SUMMARY OF THE REVISED NATIONAL PLUMBING CODE

BOARD OF MASTER PLUMBERS

Chairman: ENGR. REYNALD B. ILAGAN
Members: ENGR. PEDRITO D. CAMILET, JR
ENGR. JAIME JAJAY E. CRUZ

HISTORY OF PLUMBING PRACTICE

 Republic Act No. 1378 – Plumbing Law signed by Pres. Magsaysay.
 Republic Act No. 1364 – Sanitary Engineering Law signed by Pres. Magsaysay.
 Republic Act No. 6541 – Building Code of the Philippines
 City Ordinance 2411 – Plumbing Code for the City of Manila
 Governor General Harrison – issued a letter of proposal for proper waste disposal.
 John F. Hass – first Chief of the Division of Plumbing Construction and Inspection.
 Jaime M. Cabase – spearheaded the updating of the Revised Plumbing Code
 Feati University – Plumbing Engineering was first introduced.
 NAMPAP – National Master Plumbers Association of the Philippines
 NAWASA – National Waterworks and Sewerage Authority
 1902 – the plumbing trade was duly recognized by the government.
 1935 – NAMPAP has been registered with the Securities and Exchange Commission
 July 1956 – First licensure examination for master plumbers
 January 28, 1959 – Plumbing Code was promulgated and approved by Malacanang.
 1966-1969 – Examiners and NAMPAP prepared a curriculum for Plumbing Engineering.
 November 28, 1967 – First Amendment to the Plumbing Code was approved (inclusion
of Asbestos Cement Pipe as approved plumbing material)
 February 23, 1994 – First fully computerized examination for master plumbers
 December 21, 1999 – Section 4 of R.A. 1378 was approved by Pres. Estrada.

MASTER PLUMBER’S CODE OF ETHICS

Registered Master Plumber shall maintain a professional bearing consistent with an

honorable and dignified pursuit of his/her profession, adhering to a set of conduct
becoming his/her calling, and shall not:

1. Act in an unprofessional manner and demand any remuneration

2. Supplant another Registered Master Plumber
3. Underbid another Registered Master Plumber
4. Take advantage of a salaried government position
5. Allow the use of his/her license as a Registered Master Plumber
6. Injure falsely or maliciously, directly or indirectly, the reputation of another RMP
7. Advertise in self-laudatory language, act in any manner and engage in any practice
which tend to dishonor to the dignity of the RMP, NAMPAP, and the plumbing
profession.
22 BASIC PRINCIPLES

1. All premises shall be provided with a supply of pure and wholesome water.
2. Plumbing fixtures shall be supplied with water of sufficient volume
and adequate pressure.
3. Plumbing shall be designed and adjusted to use the minimum quantity of water.
4. Devices shall be so designed and installed to prevent from explosion.
5. Every building shall be connected to the sewer system.
6. Each family dwelling unit shall have one water closet, one kitchen sink,
a lavatory, a bathtub or shower.
7. Plumbing fixtures shall be made of smooth non-absorbent material and
be located in ventilated enclosures.
8. The drainage system shall be designed, constructed and
maintained and with adequate cleanouts.
9. All piping shall be made of NAMPAP approved materials.
10. Each fixture shall be equipped with a water sealed trap.
11. The drainage piping system shall be designed to provide adequate circulation of air.
12. Vent terminals shall extend to the outer air.
13. Plumbing systems shall be subjected to tests to effectively disclose leaks and defects.
14. No substance which will clog or destroy the pipes shall be allowed.
15. Proper protection shall be provided to prevent contamination.
16. No water closet shall be located in a room which is not properly
ventilated and lighted.
17. Suitable provision shall be made for disposing of building sewage
if there is no available sewer.
18. Suitable provision shall be made to prevent from backflow of sewage.
19. Plumbing systems shall be maintained by Registered Master Plumbers.
20. All plumbing fixtures must be properly spaced.
21. Plumbing shall be installed with due regard to preservation of
strength and prevention of damage of other structural
members.
22. Sewage that are deleterious shall not be discharged into the
ground or into any waterway.
 CHAPTER 1: ADMININISTRATION

APPLICATION FOR PERMITS

 A Registered and Licensed Master Plumber shall file an application at the
office of the Building Official in behalf of the building owner: Application shall:
 Identify & describe the plumbing work covered
 Have the description of the land upon which the plumbing work is to be done
 Indicate the use or occupancy
 Be accompanied by plans, drawings, diagrams, computations, technical
specifications, and other pertinent data required by Administrative Authority
 Be signed by the Owner or permittee
 Be signed & sealed by the Registered & Licensed Master Plumber.

 Plans & Specifications:

 All plumbing plans, drawings, diagrams, design analyses/computations as
required, technical specifications, bill of materials & other required
documents for all types of occupancy shall be prepared, signed & sealed
by a Registered & Licensed Master Plumber, without limitation pursuant to
Republic Act 1378, as amended.
 The above requirements shall be submitted in (6) sets

PERMIT ISSUANCE
 The Administrative Authority may issue Partial Permit for the construction of a
part of a large and/or complicated plumbing system before the entire plans &
specifications for the whole system submitted or approved:
 Retention of approved plans, specifications, computations & other pertinent data:
 One (1) set for Administrative Authority
 Two (2) sets returned to the Applicant
 One (1) set kept at the Jobsite
 Expiration:
 One (1) year from date of issuance
 Within 120 days if the work is suspended or abandoned

APPLICATION FOR EXISTING PLUMBING SYSTEM

 Additions, Alterations or Repairs
 Changes in Building Occupancy
 Maintenance
 Moved Buildings

INSPECTIONS
 General:
 No portion of any plumbing system shall be concealed until inspected & approved
 All Administrative Plumbing Personnel, Plumbing Inspector shall be a
Registered and Licensed Master Plumber
 Inspection Request:
 Shall be filed at least three (3) working days before such inspection is intended.
 Shall be in writing & jointly signed by Owner & the Registered and
Licensed Master Plumber-Contractor.

CONNECTION APPROVAL
 Permanent Connection: shall be approved by Administrative Authority
 Temporary Connection: shall be endorsed by Administrative Authority
 CHAPTER 2: DEFINITIONS

 ABS - Acrylonitrile-Butadiene-Styrene
 ACCESSIBLE - When applied to a fixture, connection, appliance or equipment,
shall mean having access thereto, but which may require prior removal of an access panel,
door or similar obstruction.
 READILY ACCESSIBLE - shall mean direct access without necessity of removing any panel,
door or similar obstruction
 AIRBREAK - a physical separation, which may be a low inlet into the indirect waste
receptor from the fixture, appliance or device indirectly connected.
 AIR GAP, DRAINAGE - the unobstructed vertical distance through the free atmosphere
between the lowest opening from any pipe, plumbing fixture, appliance or appurtenance
conveying waste to the flood level rim of the receptor.
 AIR GAP, WATER DISTRIBUTION - an unobstructed vertical distance through the free atmosphere
between the lowest opening from any pipe or faucet conveying potable water to the flood-
level rim of any tank, vat or fixture.
 APPROVED TESTING AGENCY - an organization primarily established for purposes of testing
to approve standards and approved by the Administrative Authority.
 BACKFLOW - the flow of water or other liquids, mixtures or substances into the distributing pipes
of a potable supply of water from any source other than from its intended source.
 BACKFLOW CONNECTION - condition or any arrangement whereby reverse flow can occur.
 BACKPRESSURE BACKFLOW - occurs due to an increased reverse pressure above the supply
pressure. This may be due to pumps, boilers, gravity or other sources of pressure.
 BACKFLOW PREVENTER - device or means to prevent flow of liquid from returning to the
source of supply. Also called “Vacuum Breaker”
 BACK-SIPHONAGE - the flowing back of used, contaminated or polluted water from a
plumbing fixture or vessel into a water supply pipe due to a negative pressure in such pipe.
 BACKWATER VALVE - a device installed in the drainage system to prevent reverse flow.
 BACKVENT PIPE - the part of the vent line, which connects directly with an individual trap
underneath or behind the fixture and extends to the branch or main vent pipe at any point
higher than the fixture or fixture traps it serves. This is sometimes called an “Individual Vent”
 BALL COCK - a valve opened & closed by the fall & rise, respectively of an attached
ball floating on the surface of the liquid.
 BALL JOINT - a type of pipe connection in which a ball-shaped end is held in a cuplike
shell and allows movements in every direction.
 BATTERY OF FIXTURES - any of two or more similar adjacent fixture which discharge into a
common horizontal soil or waste branch.
 BELL OR HUB - that portion of a pipe which, for a short distance, is sufficiently
enlarged to receive the end of another pipe of the same diameter for the purpose of making
a caulked or push-on joint.
 BENDING PIN (or IRON) - a tool for straightening or bending lead pipe.
 BIDET - Also called a “stiz” bath.
 BLANK FLANGE - a pipe flange that is not drilled for bolt holes.
 BLIND FLANGE - a flange that closes the end of the pipe. There is no opening for
the passage of liquid & gas.
 BLOW-OFF - a controlled outlet of a pipeline to discharge liquid or detritus.
 BOILER BLOW-OFF - a valve outlet of a boiler that permits discharge of accumulated sediment.
 BRANCH - any part of piping system other than the main, riser or stack.
 BRANCH INTERVAL - a length of soil or waste stack corresponding in the general to a storey
height, but in no case less than 2.43m within which the horizontal branches from one floor or
storey of a building are connected to the stack.
 BRANCH VENT - a horizontal vent connecting one or more individual vertical back
vents with the vent stack or stack vent.
 BRAZED JOINT - any joint obtained by joining of metal parts with alloys which melt
at temperatures higher than 499 degrees centigrade, but lower than the melting temperature
of the parts to be joined.
 B&S - Brown & Sharpe (Specification) or Bell & Spigot (Ends of Pipes)
 BUILDING DRAIN - that part of the lowest horizontal piping of a drainage system which receives
the discharge from soil, waste & other drainage pipes inside the walls of the building & conveys
it to the building sewer beginning 0.6m outside the building wall.
 BUILDING SEWER - that part of the horizontal piping of a drainage system which starts from the
end drain & conveys it to a public sewer, private sewer, individual sewage disposal system or
other point of disposal.
 BUILDING SUBDRAIN - that portion of an underground system, which cannot drain by
gravity into the building sewer.
 BUILDING SUPPLY - the pipe carrying potable water from the water meter or other source of
water supply to a building or other point of use or distribution on the lot. Building supply shall
also mean water service connection.
 CAULKING - plugging an opening with oakum, lead or other materials that are
pounded into the annular space. Also, the material pounded into the annular opening.
 CATCH BASIN - a receptacle in which liquids are retained for a sufficient period of
time to allow settable material to deposit.
 CERTIFIED BACKFLOW ASSEMBLY TESTER - a person who has shown competence to test and
maintain backflow assemblies to the satisfaction of the Administrative Authority having
jurisdiction.
 CESSPOOL - a non-watertight lined excavation in the ground which relieves the
discharge of a sanitary drainage system or part thereof, designed to retain the organic matter
& solids discharging therefrom, but permitting the liquid to seep through the bottom & sides of
the cesspool.
 CHASE - a vertical shaft for installation of different pipe stacks.
 CHECK VALVE - a valve that automatically closes to prevent the flow of liquid or
gas in a reverse direction.
 CIRCUIT VENT - a group vent pipe which starts in front of the extreme fixture
connection on a horizontal branch and connects to the vent stack. A.k.a. “Loop Vent”.
 COMMON VENT - A.k.a. “Loop Vent or Unit Vent”.
 COMBINATION WASTE & VENT SYSTEM - a specially designed system of waste piping embodying
the horizontal wet venting of one or more sink or floor drains by means of a common horizontal
waste & vent pipe, adequately sized to provide free movement of air above the flow line of
the drain.
 COMBUSTIBLE CONSTRUCTION - a structure which any part of its structural framework will
ignite & burn at a temperature of 756 degrees centigrade or less.
 COMMON - that part of plumbing system designed & installed to serve more than (1)
appliance, fixture, building or system.
 CONFINED SPACE - a room or space having a volume less than 1.4 m3 with 250 kilogram
calorie of the aggregate input rating of all fuel-burning appliances installed in that space.
 CONTINUOUS VENT - a continuous vent is vertical vent that is a continuation of the
drain to which the vent connects.
 CONTINUOUS WASTE - a drain connecting the compartments of a set of fixtures to trap
or connecting other permitted fixtures to a common trap.
 CONDUCTOR OR DOWNSPOUT - a vertical pipe to convey rainwater.
 CORPORATION COCK - a stop valve placed at the connection of the water service pipe
to the water main.
 CRITICAL LEVEL - C-L or C/L marking on a backflow prevention device or vacuum breaker is
a point conforming to approved standards & established by the testing laboratory (usually
stamped on the device by the manufacturer) which determines the minimum elevation
above the flood level rim of the fixture or receptacle served where the device may be
installed. When a backflow prevention devices does not bear a critical level marking, the
bottom of the vacuum breaker, combination valve or the bottom of any such approved
device shall constitute the critical level.
 CROSS-CONNECTION - any connection or arrangement, physical or otherwise, between
a potable water supply system and any plumbing fixture or any tank, receptacle, equipment
or device, through which enables non-potable, used, unclean, polluted, contaminated water
or other substances to enter into any part of such potable water system under any condition.
 DEAD-END - the extended portion of a pipe that is closed at one end to which no
connections are made on the extended portion, thus permitting the stagnation of liquid or air
therein.
 DEVELOPED LENGTH - the length of a pipe along its centerline & fittings
 DIAMATER - is the “nominal diameter” as designated commercially:
 I.D. - inside diameter
 O.D. - outside diameter
 DOMESTIC SEWAGE- the liquid & water-borne wastes derived from the ordinary living
processes, free from industrial wastes & of such character that permit satisfactory disposal
without special treatment. It is discharged into the public sewer or into a private sewage
disposal system.
 DOUBLE-BEND FITTING - a pipe fitting with adjacent reverse bends and shaped like letter “S”.
 DOUBLE OFFSET - two offsets in succession or in series such that the centerlines of the outside
ends are in the same straight line.
 DOWNSPOUT - the vertical portion of a rainwater conductor
 DRAIN - a pipe, which carries ground surface waters, storm water or
wastewater into a building drainage system.
 DRAINAGE SYSTEM - includes all the pipings within public or private premises which convey
sewage or other liquid wastes to a legal point of disposal but does not include the mains of a
public sewer system or a public sewage system or disposal plant.
 DURHAM SYSTEM - a term used to describe soil or waste system where all pipings are of
threaded pipe, tubing or other such rigid construction using recessed drainage fittings to
correspond to the types of piping.
 EFFECTIVE OPENING - is the minimum cross-sectional area at the point of water supply
discharged measured or expressed in terms of: (also applicable to air gap installation)
 Diameter of a circle
 Diameter of a circle of equivalent cross-sectional area (if the opening is not circular)
 EXISTING WORK - the on-going installation of the plumbing installation of the plumbing
system or any part thereof which has been installed prior to the effectivity of the National
Plumbing Code.
 FERRULE - a metallic sleeve, caulked or joined to an opening in a pipe, into
which a plug is screwed that can be removed for cleaning or examining the interior of the
pipe.
 FIXTURE - a receptacle other than a trap attached into a plumbing system
in which water or wastes may be collected or retained for ultimate discharge into the
plumbing system.
 FIXTURE BRANCH - the water supply pipe between the fixture supply pipe & the water-
distributing pipe.
 FIXTURE DRAIN -the drainpipe from the trap of a fixture to the junction of that
drain with any other drainpipe.
 FIXTURE SUPPLY - a water supply pipe connecting the fixture with the fixture branch.
 FIXTURE UNIT - is an arbitrary quantity in terms of which the load producing effects
of water requirements on the plumbing system of different kinds of plumbing fixtures are
expressed in some arbitrary chosen scale.
 One fixture unit is equivalent to a rate of flow at 28.3 liters per minute or (1 cu.
ft. per minute)
 FLOOD LEVEL - the level in a fixture at which water begins to overflow over the
top of rim of the fixture.
 FLOOD LEVEL RIM - is the top edge of the receptacle from where water overflows.
 FLOODED - a fixture is flooded when the liquid therein rises to the flood level rim.
 FLUSH TANK - a tank located above or integral with water closet, urinal or similar
fixtures for flushing or removing excrements in the fixture.
 FLUSH VALVE - is a device located at the bottom of the tank for the purpose of
flushing water closet or similar fixtures.
 FLUSHOMETER TANK - is integrated within a n air accumulator vessel which is designed to
discharge a predetermined quantity of water into fixtures for flushing purposes.
 FLUSHOMETER VALVE - is a device, which discharges a predetermined quantity of water
into fixtures for flushing purposes & is actuated by direct water pressure.
 GATE VALVE - a valve in which the flow of water is cut off by means of a circular
disc fitted against a machine-smoothed faces, at right angles to the direction of flow. The disk
is raised or lowered by means of a threaded stem connected to the handle of the valve. The
opening in the valve is usually as large as the full bore of the pipe.
 GLOBE VALVE - a valve in which the flow of fluid is cut off by means of a circular
disc that fits over & against the horizontal valve seat. The movement of the plane of the disc
is parallel to the normal direction of flow of water through the orifice (hole) resulting to tortuous
passage which offers a high-pressure loss. (to throttle water pressure)
 GOOSENECK - a return bend of a small sized pipe, one end of which is about
30cm long & the other end is about 7.5cm long. It is commonly used as a faucet for a pantry
sink. Also, the term means the flexible tubing connection between the service pipe & the water
main.
 GREASE INTERCEPTOR -an interceptor of at least 3 cubic meters capacity to serve one or
more fixtures which is remotely located.
 GREASE TRAP - a device designed to retain grease from 1 to a maximum of 4 fixtures.
 GROUP VENT - a branch vent that performs its functions for 2 or more traps
 HORIZONTAL BRANCH - is a drain pipe extending laterally from a soil or waste stack or building
drain with or without vertical sections or branches, which receives the discharge from one or
more fixture drains and conducts it to the soil or waste stack or to the building drain.
 HORIZONTAL PIPE - is any pipe or fitting installed in a horizontal position or which forms an angle of
not more than forty-five 45 degrees from the horizontal plain.

 HOUSE DRAIN - is that part of the lowest horizontal piping of a plumbing system
which receives the discharges from soil, waste and other drainage pipes inside of a building
and conveys it to the house sewer outside of the building.
 HOUSE SEWER - is that part of a plumbing system extending from the house drain
at a point 0.60m from the outside face of the foundation wall of a building to the junction with
the street sewer or to any point of discharge, and conveying the drainage of one building site.
 HOUSE STORM SEWER - is the pipeline from the building to the public or street storm drainage
system.
 HUBLESS PIPES - are cast iron soil pipes with plain ends connected together with
bolted stainless steel bands and neoprene gaskets.
 INDIRECT WASTE PIPE - is a pipe that does not connect directly with the drainage
system but conveys liquid wastes by discharging into a plumbing fixture, interceptor or
receptacle directly connected to the drainage system.
 INDIVIDUAL VENT - is a pipe installed to vent a fixture trap & which connects with the vent
system above the fixture served to terminate in the open air. (a.k.a. backvent)
 INDUSTRIAL WASTE- any and all liquid or water-borne waste from industrial or commercial
processes, except domestic sewage.
 I.P.S. - means Iron Pipe Size
 INSANITARY - a condition contrary to sanitary principles or injurious to health.
 INTERCEPTOR (CLARIFIER) - is a device designed & installed to separate & retain deleterious,
hazardous or desirable matters from normal wastes & permits normal sewage or liquid wastes
to discharge into the disposal terminal by gravity.
 INVERT - the lowest portion of the interior part of any pipe or conduit that is
not vertical.
 LABELLED - equipment or materials bearing a label of a listing agency. All labels shall
be embossed, stamped or indelibly marked with stickers, glued on the finished product
indicating the weight, specifications & logo of the manufacturer.
 LATERAL
 In plumbing – A secondary pipeline
 In sewerage – A common sewer to which no other branch sewer is connected.
It receives sewage from building sewer service connections only.
 LATRINE - a water closet consisting of a continuous through containing
water. The though extends under two or more adjacent seats. Prohibited by health authorities
for permanent installations.
 LAVATORY - a.k.a. wash basin
 LEACHING CESSPOOL - a cesspool that is not watertight.
 LEADER - a pipe connected from building gutter to the downspout or conductor.
 LENGTH OF PIPE - is measured along its centerline
 LIQUID WASTE - is the discharge from any fixture, appliance or appurtenance in
connection with a plumbing system which does not receive fecal matter.
 LOCAL VENT - a pipe or shaft to convey foul air from a plumbing fixture or a room
to the outer air.
 LOOP OR CIRCUIT VENT - a vertical vent connection on a horizontal soil waste pipe branch at
a point downstream of the last fixture connection and turning to a horizontal line above the
highest overflow level of the highest fixture connected thereat; the terminus connected to the
stack vent in the case of loop venting or to the vent stack nearby in the case of circuit venting.
 MAIN - any system of continuous piping, which is a principal artery of the
system were branches are connected.
 MAIN VENT - the principal artery of the venting system to which vent branches are
connected.
 MOBILE HOME PARK SEWER - that part of the horizontal piping of sanitary drainage
system which measures 0.6 meter downstream from the last mobile home site and conveys
sewage to a public sewer, private sewer, individual sewage disposal system or other points of
disposal.
 NUISANCE - any work regulated by the “Plumbing law” that is dangerous to human life
or detrimental to health & property
 OAKUM - hemp or old hemp rope soaked in oil or tar to make it waterproof.
 OFFSET - in a line of piping is a combination of elbows or bends, which brings
one section of the pipe out of the line but into a line parallel with the original section.
 PB (POLYBUTELENE) - tube made of plastic material colored black. The cross-sectional
shape is normally oval and is denoted by its outside diameter (O. D.). Normally used as water
service connection from main to meter.
 PE (POLYETHYLENE)- tube made of plastic material colored black. The cross-sectional shape is
circular and is denoted by its outside diameter (O. D.).
 PIPE - a cylindrical conduit or conductor conforming to the particular
dimensions commonly known as “pipe size” & its denoted by its interior diameter (I. D.).
 PLUMBING - the art & technique of installing pipes, fixtures & other apparatuses in
buildings for bringing the supply, liquids, substances &/or ingredients & removing them; & such
water, liquid & other carried-wastes hazardous to health, sanitation, life, property; also the
pipes and fixtures after installation i.e., the plumbing system.
 PLUMBING APPLIANCE – any one of a special class of device or equipment intended to
perform a special plumbing function. Such device or equipment may operate automatically
or may be manually adjusted or controlled by the user or operator.
 PLUMBING APPURTENANCE - a manufactured device or a prefabricated assembly or an
on- the-job assembly of component parts, and serves as adjunct to the basic piping system &
plumbing fixtures. An appurtenance demands no additional water supply nor does it add any
discharge load to a fixture or the drainage system. It performs some useful functions in the
operation, maintenance, servicing, economy or safety of the plumbing system.
 PLUMBING FIXTURES - are approved-type installed receptacles, devices or appliances
supplied with water or receive liquid or liquid-borne wastes and discharge such wastes into the
drainage system to which they may be directly or indirectly connected. Industrial or
commercial tanks, vats & similar processing equipment are not plumbing fixtures, but may be
connected to or discharged into approved traps or plumbing fixtures.
 PLUMBING SYSTEM- includes all potable water supply & distribution pipes, all plumbing fixtures
& traps; all sanitary & storm drainage systems; vent pipes, roof drains, leaders & downspouts;
& all building drains & sewers, including their respective joints & connections; devices,
receptacles, tap, hot & chilled water pipings; potable water treating or using equipment; fuel
gas piping; water heaters & vents for same.
 PLUMBING UNIT - a minimum standard quantity of plumbing fixtures that discharge wastes into
a plumbing installation including:
 1 water meter
 1 water closet
 1 lavatory
 1 shower head & drain for a bathtub or shower stall
 1 kitchen sink
 1 laundry tray
 3 floor drains
 4 faucets/hose bibb
 PRESSURE - the normal force exerted by a homogeneous liquid or gas, per unit of area
on the wall of the container
 Static Pressure - the pressure existing without any flow of motion
 Residual Pressure - the pressure available at the fixture or water outlet;
allowance is made for pressure drop due to friction loss, head, meter & other
losses in the system during maximum demand period.
 PRIMARY BRANCH - of the building drain is the single sloping drain from the base of a stack to
its junction with the main building drain.
 PRIVATE SEWAGE DISPOSAL SYSTEM – a septic tank with the effluent discharging into a
subsurface disposal field, into one or more seepage pits or into a combination of subsurface
disposal field & seepage pit or of such other facilities as may be permitted under the
procedures set forth elsewhere in the Plumbing Code.
 PRIVATE SEWER - a building sewer, which receives the discharge from more than one
building drain & conveys it to the public sewer, private sewage disposal system, or other
points of disposal.
 PRIVY - an outhouse or structure used for the deposition of excrement.
 PRIVY VAULT - a pit beneath a privy where excrement collects.
 PUBLIC SEWER - a common sewer directly controlled by public authority to which
all abutters have equal rights of connections.
 PVC (POLYVINYL CHLORIDE)
 Potable water pipings - color-coded BLUE
 Drainpipes - color-coded GRAY, ORANGE or BROWN
 QUALITY OF MATERIALS - all plumbing fixtures and materials used in any discharge or plumbing
system or parts thereof shall be free from defects.
 RECEPTOR - an approved plumbing fixture device of such materials, shape & capacity
to adequately receive the discharge from indirect waste pipes, constructed & located to be
readily cleaned.
 REGULATING EQUIPMENT - include all valves and controls used in plumbing systems which are
accessible.
 RELIEF VENT - a vertical vent line, the primary function of which is to provide
additional circulation of air between the drainage & vent systems or to act as an auxiliary vent
on a specially designed system such as a “yoke vent” connection between the soil & vent
stacks.
 RETURN BEND - an open return bend usually made up of two 90degree bends with
inside & outside threads, flanged, or welded fittings; and also applied to 180degrees bend in
copper tubing.
 RIM - an unobstructed top open edge of a fixture.
 RISER - a water supply pipe, which extends vertically to one full story or
more to convey water into a pipe branches or plumbing fixtures.
 ROUGHING-IN - the installation of all pipings and fitting parts of the plumbing
system, which can be completed prior to the installation of fixtures & accessories. These
include sanitary & storm drainage, tap, hot & chilled water supplies, gas pipings, vent pipings
& the necessary fixture supports.
 SANITARY SEWAGE - the wastewater containing human excrements & liquid household waste.
Also called domestic sewage
 SEAL - the vertical distance between the dip & the crown weir of a trap.
Also, the water in the trap between the dip & the crown weir.
 SECONDARY BRANCH - any branch in the building drain or other than the primary branch.
 SEEPAGE PIT - a loosely lined excavation in the ground, which receives the
discharge of a septic tank & designed to permit the effluent from the septic tank to seep
through pit bottom & sides.
 SEPTIC TANK - a water-tight receptacle which receives the discharge of a
sanitary plumbing system or part thereof, designed & constructed to retain solids, digest
organic material through a period of detention & to allow the liquids to discharge into the soil
outside of the tank through a system open-jointed sub-surface pipings or a seepage pit.
 SERVICE PIPE - the pipe from the street water main or other source of water supply
to the building served.
 SEWAGE - any wastewater containing animal or vegetable matter in
suspension or solution and may include liquids containing chemicals in solution.
 SEWER - a pipe or conduit for carrying sewage & wastewater.
 SEWERAGE OR SEWERAGE WORKS - a comprehensive term, including all constructions for
collection, transportation, pumping, treatment & final disposition of sewage.
 SHAFT - a vertical opening through a building for elevators, dumbwaiters,
lights, ventilation or similar purposes.
 SIAMESE CONNECTION - a hose fitting with clapper valves for combining the flow from two or
more lines of hose into a single stream. The inlet fitting of a fire standpipe located above
ground level.
 SIPHONAGE - a suction created by the flow of liquids in pipes. A pressure less
than atmospheric.
 SHIELDED COUPLING - an approved elastomeric sealing gasket with an approved outer
shield & a tightening mechanism.
 SLIP JOINT - an adjustable tubing connection, consisting of a compression nut, a
friction ring, & a compression washer, designed to fit a threaded adapter fitting or a standard
taper pipe thread.
 SOIL STACK PIPE - a vertical soil pipe conveying fecal matter & wastewater.
 SOIL PIPE - any pipe, which conveys the discharge water from water closet, urinal or
fixtures having similar functions, with or without the discharges from other fixtures to the building
drain or building sewer.
 SOLDERED JOINT - a pipe joint obtained by joining metal parts with metallic fixtures or alloys
which melt a temperature below 427 degrees centigrade & above 149 degrees centigrade.
 SPIGOT - the end of a pipe which fits into a bell. Also a word used
“synonymously with faucet”.
 SPECIAL WASTE - wastes which require some special methods of handling such as the use of
indirect waste piping & receptors; corrosion-resistant piping; sand, oil or grease interceptors;
condensers or other preteatment facilities.
 STACK - the vertical main of a system of soil, waste or vent pipings
extending through one or more stories & extended thru the roof
 STANDPIPE - a vertical pip, or a reservoir, into which water is pumped to give it at a
head, classified as:
 Wet Standpipe - water pressure is maintained at all times
 Automatic Standpipe System - operates automatically by opening a hose
valve
 Manually-Operated Standpipe System - remote control device at each
hose station
 Dry Standpipe - having no permanent water inside the pipe.
 STORM WATER - that portion of the rainfall or other precipitation which runsoff over
the earth surface after a storm
 SUBSOIL DRAIN - an underground drainpipe that receives only sub-surface or
seepage water & convey it to a sump for disposal by gravity flow or by lift pump.
 STACK VENT - an extension of a soil or waste stack above the highest horizontal
drain connected to the stack. The uppermost end above the roof is called “Stack Vent Through
Roof” (SVTR).
 SUMP - an approved tank or pit which receives sewage or wastewater
and is located below the normal grade of the gravity system & must be emptied by
mechanical means.
 SUPPORTS - supports, hangers, anchors, brackets, cradles, are devices for holding &
securing pipes and fixtures to walls, ceiling, floors or structural members.
 SURFACE WATER - that portion of rainfall or other precipitation which runs off over the
surface of the ground.
 TAILPIECE - the pipe or tubing that connects the outlet of a plumbing fixture to the trap.
 TAPPED TEE - a tee with the branch tapped to receive a threaded pipe or fittings.
 TRAP - a fitting or device designed and constructed to provide, when
properly vented, a liquid seal prevents the backflow of foul air or methane gas without
materially affecting the flow of sewage or wastewater through it.
 TRAP ARM - that portion of a fixture drain between a trap and a vent.
 TRAP SEAL - the maximum vertical depth of liquid that a trap will retain, measured
between the crown weir & the top of the dip of the trap.
 TUBE - a cylindrical conduit or conductor conforming to the particular
dimensions known as “tube sizes” & denoted by its outside diameter (O.D.).
 UNCONFINED SPACE - a room space having a volume equal to at least 1.4 m3 of the
aggregate input rating of the fuel-burning appliance installed in that space. Rooms adjacent
and open to the space where the appliance is installed, through openings not furnished with
doors, are considered a part of the unconfined space.
 UNIT VENT - an arrangement of venting so installed that one vent pipe will serve (2) traps.
 VACUUM - air pressure less than atmospheric. Also, implies siphonage, in
piping system.
 VACUMM PREVENTER - see Backflow Preventer.
 VENT PIPE - a pipe or opening used for ensuring the circulation of air in a plumbing
system & for leaving the negative pressure exerted on the trap seals.
 VENT STACK - the vertical vent pipe installed primarily for providing circulation of
air to & from any part of the soil, waste of the drainage system.
 VENT SYSTEM - pipes installed to provide flow of air to or from a drainage system
or to provide a circulation of air within such system to protect trap seals from siphonage &
back pressure.
 VERTICAL PIPE - any pipe or fitting installed in a vertical position or which forms an
angle of not more than forty-five (45) degrees with the vertical line.
 WASTE PIPE - a pipe, which conveys only wastewater or liquid waste of fecal matter.
 WATER TREATMENT - a device which conditions or treats water supply to improve
water quality, remove suspended solids by filtration.
 WATER - DISTRIBUTING PIPE - a pipe which coveys potable water from the
building supply pipe to the plumbing fixtures & other water outlets.
 WATER MAIN - or street main is the water-supply pipe for public or community use.
 WATER SUPPLY SYSTEM - of a building or premises consists of the water service pipe, water
supply line, water distributing pipe and the necessary branch pipes, fittings, valves all
appurtenances required for the supply of potable water.
 WET VENT - that portion of a vent pipe through where wastewater also flows
through.
 WELDED JOINT OR SEAM - any joint or seam obtained by the joining of metal parts in a plastic
molten state.
 WELDER, PIPELINE - a person who specializes in the welding of pipes & holds a valid certificate
of competency from a recognized testing agency, based on the requirements of the
regulating authority.
 WYE - a hose connection with two-gated outlets permitting two
connections of the same or smaller coupling diameter to be taken from a single supply line.
Also, a pipe fitting of three branches that form the letter “wye”.
 YOKE VENT - a pipe connecting upward from a soil or waste stack below the floor &
below horizontal connection to an adjacent vent stack at a point above the floor & higher
than the highest spill level of fixtures for preventing pressure changes in stacks.

CHAPTER 3: GENERAL REGULATIONS

GRADE OF HORIZONTAL PIPING

 Drainage pipes shall be run in practical alignments & at a uniform slope between
manholes of not less than 20mm/m or 2% toward the point of disposal.
If it is impracticable to obtain such slope due to the following conditions:
 Excessive depth of the proposed drainage line
 Structural and/or geological features of the terrain
 Existing adverse in arrangements of building structure
Any such pipe or piping 102mm or larger in diameter may have a slope of 10mm/m or 1%
provided it is approved by Administrative Authority

CHANGES IN DIRECTION OF DRAINAGE FLOW

 Changes in direction of piping shall be made by the use of approved pipe fittings &
shall be the angles presented by:
 22 ½ degrees bend
 45 degrees bend
 60 degrees bend or other approved fittings of longer sweeps.
 Horizontal drainage lines connecting to a vertical stack shall enter through:
 45 wye branches
 combination wye & 1/8 bend branches
 or other approved fittings of longer sweeps.
 Horizontal drainage lines connecting to other horizontal drainage lines shall enter through:
 45 wye branches
 combination wye & 1/8 bend branches
 or other approved fittings of longer sweeps.
 Vertical drainage lines connecting to other horizontal drainage line shall enter through:
 45 wye branches
 or other approved fittings of longer sweeps.
 60 degree branches or offsets (only for pipes installed in true vertical position)
PROHIBITED FITTINGS & PRACTICES
 No Drainage Fitting shall use:
 Double hub fitting for leak-caulked joint in vertical position
 Single or double tee branch
 Single or double tapped tee branch
 Side inlet quarter bend
 Running thread, band or saddle
Except that: double hub sanitary tapped tee may be used on vertical lines as a fixture
connection. (approved stainless steel bands with neoprene gaskets for jointing hubless
cast iron soil pipes are acceptable for use)
 No Drainage or Vent piping shall be drilled & tapped for making connections
thereto, and no cast iron soil pipe shall be threaded.
 No Waste Connection shall be made to a closet bend or stub of a water closet or
similar fixtures.
 No Vent pipe shall be used as a soil or waste pipe & vice versa

PROTECTION OF PIPING, MATERIALS & STRUCTURES

 All pipings passing under or through walls shall be protected from breakage with
embedded metal pipe sleeves.
 All pipes passing through or under cinders or other corrosive materials shall be
protected from external corrosion by encasing same with polyethylene sheath or in
any other approved manner.
 Void between pipes & sleeves through concrete floors in the ground shall be appropriately
sealed with bitumen.
 The bottom of all pipe trenches deeper than the footing of any adjacent building or
structure & parallel to it must be at least 45degrees therefrom, unless permission is
granted by Administrative Authority.
 No building sewer or other drainage pipings or part thereof, constructed of materials
other than that approved for use under or within the building, shall be installed under
or within 0.6m of any building or structure, nor less than 0.3m below the finish ground
surface.

HANGERS & SUPPORTS

 VERTICAL PIPING:
 Cast Iron Soil Pipe - Bell & Spigot & Hubless pipe shall be supported at every
storey or closer.
 Screwed Pipe - Iron Pipe Size (IPS) shall be supported at not less than every other
storey height.
 Copper Tubing - shall be supported at each storey or at a maximum intervals of 3m o.c.
 Lead Pipe - shall be supported at intervals not exceeding 1.20m at centers
with a rigid vertical back-up
 Plastic Pipe - shall be supported at every 1m interval.

 HORIZONTAL PIPING:
 Cast Iron Soil Pipe
a. Suspended cast iron soil pipe shall be supported at not more than 1.5m
intervals, except that pipe exceeding 1.5m length may be supported at not
more than 3m intervals. Supports shall be adequate to maintain alignment & to
prevent sagging & shall be placed within 0.45m of the hub or joint.
b. Hubless or compression gasket joints must be supported at least every other
joint except that when the developed length between supports exceeds 1.2m,
they shall be provided at each joint.
 Screwed Pipe - IPS shall be supported at approximately 3.0m intervals for piping
19mm diameter & smaller & 3.6m intervals for piping 25mm & larger in diameter.
 Copper Tubing - shall be supported at approximately 1.8m intervals for piping
38mm diameter & smaller & 3.0m intervals for piping 51mm & larger in dia.
 Lead Pipe - shall be supported at by stiff metal or wooden backing for entire
length with hangers properly spaced.
  In Ground - piping buried on the ground shall be laid on the firm bed for its
entire length, except where concrete cradle support is provided which is
adequate & approved by the Administrative Authority.
 Plastic Tube - shall be supported by stiff metal or wood backing with hangers in its
entire length for small-size tubings up to 38mm diameter & without backings but
with spaced metal hangers at approved spacing for larger-size tubings.

TRENCHING, EXCAVATION & BACKFILL

 Tunnels shall have:
 a clear height of 0.6m above the pipe & shall be limited in length to 1/2 the depth
of the trench.
 2.4m max. length & shall be limited in length to 1/2 the depth of the trench.
 driven pipes shall have at least one pipe size larger than the pipe to be laid

 Trenches shall be back-filled in thin layers of 0.3m above the top of the pipe with clean
earth which shall not contain stones, boulders, cinders or other materials which can
damage or break the pipes or cause corrosive action.
 CHAPTER 4: PLUMBING FIXTURES

MATERIALS – GENERAL REQUIREMENTS

 All porcelain enamel surfaces on plumbing fixtures shall be acid resistant
 Water closet bowls for public use shall be elongated bowl types equipped with open-
front seats.
MATERIALS – ALTERNATIVES
 Restaurant kitchen & other special-use sink may be made of approved-type
bonderized & galvanized sheet steel not less than Ga.16 U.S. B&S or 1.6mm thk.
STAINERS & CONNECTIONS
 Strainers serving shower drains shall have a waterway equivalent area of the
“tailpiece” – meaning, the sum of all the areas of the perforation of the strainer is
equivalent to the outlet area.
 Fixtures having concealed slip joint connections shall be provided with an access
panel or utility at least 0.3m in its least dimension for inspection & repair.
 Continuous waste fixture tailpiece connections were exposed or accessible may be of
seamless drawn brass not less than Ga. 20 B&S or 0.8mm thk.

 Continuous waste or waste & overflow shall not be less than:

 38mm outside dia. (O.D.) for:
- sinks, dishwashers, laundry tubs, bathtubs, & similar fixtures
- urinals (brass & copper-not allowed!)
 32mm outside dia. (O.D.) for:
- lavatories, drinking fountains & similar small fixtures
SPECIAL FIXTURES & SPECIALTIES
 Wastewater drain for “Sacrarium” cupsink at church altar & baptisteries font outlet shall
discharge direct to the ground & not connected to any sanitary or drainage system.
INSTALLATION
 No water closet or bidet shall be set closer than 0.375m from its center to any side of
the wall or obstruction or closer than 0.75m center to center to any similar fixture.
 No urinal shall be set closer than 0.6m center to center.
SHOWER STALLS
 Each shower receptor shall be a n approved type and be constructed to have a
finished dam, curb, or threshold which is at least 25.4mm lower than the outside floor.
 In no case shall any dam or threshold be less than 51mm or more than 228mm in depth
when measured from the top of the dam or threshold of the drain.
 The finished floor of the receptor shall slope uniformly from sides towards the drain not
less than 2% or 20mm/m or more than 4% or 40mm/m.
 559mm min. width of threshold.
 1.2m min. distance between the door or entry to the drain.
 0.6m2 min. finished interior area of shower stalls (any shape) & shall be capable of
encompassing a 762mm dia. circle.
 The minimum area & dimensions shall be maintained from a point above the shower
drain outlet to a height of 1.78m with no protrusions other than the fixture valve or
valves, shower head & safety grab bars or rails.
 When shower receptors are built above ground the sub-floor & rough side of walls to a
height of no less than 76mm above the top of the finished dam or threshold.
 No metallic shower sub-pans or linings may be built-up on jobsite of not less than (3)
three layers of standard grade 6.8kg asphalt-impregnated roofing felt. All folds, laps &
reinforcing webbing shall extend to at least 101mm in all directions producing a tensile
strength of not less than 0.9kg/mm in either directions.
 For public showers: drains in gutters shall not be spaced more than 4.9m apart.
 48.880C max. temperature of hot water in showers & shall have:
 individual shower control valves of the pressure balance or the thermostatic mixing
valve type for individual water heaters
 master thermostatic mixing valve type in lieu of individually controlled pressure
balance or the for multiple gang showers
 MINIMUM RATIO of PLUMBING FACILITIES
 1 laundry tray & 1 automatic washer standpipe per 1 dwelling unit
 2 laundry trays & 2 automatic washer standpipes per 10 apartments
 1 kitchen sink per 1 dwelling unit or 1apartment
 1 lavatory per 5 persons (where there is exposure to skin contamination with
poisonous, infectious, or irritating materials)
 1 laundry tray per 50 persons
 1 slop sink per 100 persons
 1 water closet & 1 urinal per 30 workmen (for temporary workingmen facilities)
 1 drinking fountain per occupied floor in schools, theaters, auditoriums, dormitories
offices or public building
 total no. of water closets required for females shall be at least equal for the total no.
of water closets & urinals required for males.
 For assembly areas (theaters, auditoriums, dormitories, offices, of public buildings) used by
more than 6 persons:
 1 drinking fountain for the first 75 persons & additional of 1 drinking fountain for the next
150 persons.
 CHAPTER 5: INSPECTION & TESTS
 It is the duty of the Registered & Licensed Master Plumber to notify the Administrative
Authority not less than 3 days before the work is inspected.
 In water testing, the water shall be kept in the pipe system or in the potion under test
for at least 15 minutes before the inspection starts.
 In air testing, after closing all other inlets & outlets, air is forced in the pipe system
(through a connection with an air compressor), until there is a uniform gauge pressure
of 34.5 Kpa sufficient to balance a column of mercury 254mm in height for a period of
at least 15 minutes.
 In water piping, it shall be tested & proved tight under water pressure not less than the
working pressure which is to be used plus 50% for a period of at least 15 minutes. A
344.5 Kpa air pressure may be substituted for the water test.

CHAPTER 6: WATER SUPPLY AND DISTRIBUTION

BACKFLOW PREVENTION DEVICES, ASSEMBLIES, & METHODS

 AIR GAP - the minimum air gap to provide backflow protection.

 EFFECTIVE OPENING - the minimum cross sectional area at the seat of the control valve
or the supply pipe or tubing which feeds the device outlet. If two or more lines supply one
outlet, the effective opening shall be the sum of the cross-sectional areas of the individual
supply lines or the area or the single outlet, whichever is smaller.

 ATMOSPHERIC VACUUM BREAKER (AVB) - consist of a body, a checking member & an

atmospheric opening.

 DOUBLE CHECK VALVE BACKFLOW PREVENTION ASSEMBLY (DC) - consists of two independently
acting internally or externally loaded check valves, four properly located test cocks with
connectors & two isolation gate valves.

 PRESSURE VACUUM BREAKER BACFLOW PREVENTION ASSEMBLY (PVB)

- consists of a loaded air inlet valve, an internally loaded check valve, two properly
located test cocks & two isolation gate valves.

 REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTION ASSEMBLY (RP)

- consists of two independently acting internally loaded check valves, a differential
pressure relief valve, four properly located test cocks & two isolation gate valves.
GENERAL REQUIREMENTS
 Access & clearance for testing, maintenance & repair shall require 305mm min. space
between the lowest portion of the assembly & the grade, floor or platform. Elevated
installations more than 1.52m above the floor or grade shall be provided with platform
sufficient to support maintenance person.
 Where potable water is discharge to the drainage system, it shall be by means of an
approved air gap of two (2) pipe dia. min. to 25mm max. from the supply outlet & the
top surface of the drainage inlet.

SPECIFIC REQUIREMENTS
 Water Closet & Urinal Flushometer Valves shall be equipped with a listed atmospheric
vacuum breaker & shall be installed at the discharge level of the flushometer valve
with a critical level at least 152mm distance according to its listing above the overflow
rim of a water closet bowl or highest part of a urinal.
 Water Closet & Urinal Tanks shall be equipped with a listed ballcock & shall be installed
with the critical level at least 25mm above the full opening of the overflow pipe.
 152mm minimum installation of a listed atmospheric vacuum breaker:
 in the discharge side of the last valve for inlets to Tanks, Vats, Swimming Pools &
other receptors.
 above the highest point of usage & located on the discharge side of the last valve for
Potable Water Outlets with Hose Attachments. &
 above the aspirator unit for Water Inlets to Water Supplied Aspirators.

MATERIALS
 Water pressure pipes shall be of:
 For cold-water distribution systems - Brass, Copper, Centrifugal Cast Iron Pipe (CCI),
B&S & F&F ends, Ductile Cast Iron Pipe (DCI), Galvanized Wrought Iron, Galvanized
Steel, or other approved PE & PVC water pressure pipe.
 For hot & cold-water distribution systems- CPVC water pipe & tubing
 Cast iron fittings up to & including 51mm in size, when used in connection with potable
water piping shall be galvanized.
 All small-sized malleable iron water fittings shall be galvanized.
 Water pipes & fittings with a lead content that exceed 8% shall be prohibited & shall
not be used in potable piping systems.

VALVES
 Valves up to & including 51mm size shall be brass or other approved materials. Sizes
over 51mm may have cast iron or brass bodies. Each gate valves shall be a fullway
type with working parts of non-corrosive materials.
 A valve used to control two (2) or more openings shall be a fullway gate valve.

GRAVITY SUPPLY TANKS

 Covers of gravity tanks shall be vented with a return-bent vent pipe having an area
not less than the area of the down-feed riser pipe.
 For overflow control, inlets shall be controlled by a float valve, float switch or
electrode- type water level control.
 Shall have a valved drain pipe & an screened overflow pipe

WATER PRESSURE, PRESSURE REGULATORS & PRESSURE RELIEF VALVES

 Inadequate water pressure – water pressure less than 103 Kpa
 Excessive water pressure – water pressure greater than 551 Kpa
 All pipe determinations shall be based on eighty percent (80%) the reduced pressure.
 For listed non-storage instantaneous heaters having an inside diameter of not more
than 76mm is not required to have pressure relief valve with approved drain.
 Each pressure relief valve shall be an approved automatic type with drain, & each
such relief valve shall be set at a pressure not more than 1033 Kpa.
 approved Combination Temperature & Pressure Relief Valve (CT & PRV)

INSTALLATION, INSPECTION, & TESTING

 All water service yard piping shall be at least 0.3m below the finish ground level.
 Water pipes if run or laid with the same trench or building sewer shall be:
 Min. of 0.3m above the top sewer or drain line (may be constructed of clay or
materials no approved for use within a building)
 Placed on a solid shelf excavated on one side with min. of 0.3m clearance from
the side of sewer, drain line & the water line
  Unions shall be installed in the water supply piping within 0.3m away from regulating
equipment, water heater, conditioning tanks & similar equipment which require
removal for servicing or replacement.

SIZE OF POTABLE WATER PIPING

 “Size of water piping shall be based on the total water demand”
 The quantity of water required to be supplied to every plumbing fixture shall be
represented by “Fixture Units” (FU)
 61m max. length of supply piping.
 No building water service pipe shall be less than 19mm in diameter.

EQUIVALENT WATER SUPPLY FIXTURE UNITS

SUPPORT
 Support all piping at intervals of not more than (4ft.) four feet or (1219mm), at
end of branches & change of direction or elevation.
 Support trap arms in excess of (3ft.) three feet or (914mm) in length as close as
possible to the trap.
 Closet rings shall be fastened (1/4inch) or (6.4mm) above finished floor.
THRUST BLOCKING
 In lines with rubber gasketed joints, thrust blocks shall be installed at all:
 Changes in direction, as tees & bends
 Changes in size, as at reducers
 Stops, as at dead ends; &
 Valves, where thrusts may be expected.
 CHAPTER 7: EXCRETA DRAINAGE SYSTEM

MATERIALS
 Excreta Drainage Pipings shall be of Cast Iron, Ductile Iron, Galvanized Steel,
Galvanized Wrought Iron, Lead, Copper, Brass, Series 1000 PVC DWV, Extra-strength
Vitrified Clay Pipe or other approved materials having smooth & uniform bore except
that:
 No Galvanized Wrought Iron or Galvanized Steel Pipe shall be used underground & shall be
kept at least 152mm above ground.
 No Vitrified Clay Pipes or Fittings for building drain or sewer shall be used above ground
or whenever piping is pressurized by a pump or ejector. They shall be kept 0.3m below
finish ground level.
 Drainage Fittings shall be Cast Iron, Malleable Iron, Lead, Copper, Brass, ABS, PVC,
Vitrified Clay Pipe or other approved materials having smooth interior waterway of the
same diameter as the piping served.
 ABS & PVC DWV piping installations shall be used in high rise buildings
SIZE OF DRAINAGE PIPING
 Minimum Trap Diameters & Drainage Fixture Unit Values
CHANGES IN DIRECTION OF EXCRETA DRAINAGE FLOW
 Changes in direction of drainage piping shall be made by appropriate use of
approved fittings & shall be of the angles presented by a 22 ½ degrees or 1/16 bend,
45degrees or 1/8 bend, and 60degrees or 1/6 bend or other approved fittings of
equivalent sweeps.
 Vertical drainage lines connecting with horizontal drainage lines shall enter through
forty- five (45) degree branches or other approve fittings of equivalent sweep. Sixty
(60) degree branches or offsets may be used only installed in a true vertical position.

CLEANOUTS
 Each horizontal drainage pipe shall be provided with a cleanout at its upper terminal
& each rung of piping which is more than 15 meters in total developed length shall be
provided with a cleanout & every 15 meter length or a fraction thereof.

 Cleanouts may be omitted:

 On horizontal drain less than 1.5 meter in length unless such line is serving sink or
urinals.
 On short horizontal drainage pipe installed at a slope of seventy-two (72) degrees
or less from the vertical line (or an angle 1/5 bend).
 Additional cleanout shall be provided on a horizontal line with an aggregate offset
angle of direction exceeding 135 degrees.
 Each 90degrees cleanout extension shall be extended from a wye type fitting or
other approved fitting of equivalent sweep
 Clearances in front of the cleanout:
 in piping 51mm or less shall have clearance of not less than 305mm in front of the
cleanoout.
 in piping 51mm or larger shall have clearance of not less than 450mm in front of
the cleanoout.
 in underfloor piping shall be extended to or above finish floor or shall be extended
outside the building when there is less than 450mm vertical & 750mm horizontal
clearance from means & access to such cleanout.
 6.1m max. distance from an access door, trap door, or crawl hole (in residential)
DRAINAGE OF FIXTURES LOCATED BELOW THE UPSTREAM MANHOLE OR BELOW THE
MAIN SEWER LEVEL
 The minimum size of any pump discharge or any discharge pipe from a sump having
a water closet connected thereto shall not be less than 50.8mm diameter.
 All such pumps & receiving tanks shall be automatically discharged & when rated
“public use” shall be provided with dual pumps or ejectors. The invert of the lowest
inlet to the tank shall have a 51mm min. distance above the high water or “starting”
level of the pumping operation.
 Vent of sump & receiving tanks shall extend separately to the roof having a 51mm min.
 Air tanks for ejector shall have an air pressure of 3kg min. for each meter of height the
sewage is raised.
 Fixture outlets shall not be connected to the horizontal excreta drainage piping system
within 2.4m of any vertical to horizontal change of direction of a stack containing suds-
producing fixtures. (Fixtures using soaps/detergents)
 The diameter of an individual vent shall not be less than 32mm nor less than 1/2 the
diameter of the drain to which it is connected.

CHAPTER 8: INDIRECT WASTE PIPING, WET VENTED SYSTEMS

AND SPECIAL WASTES

INDIRECT WASTE CONDITIONS

 The airgap for drainage shall be not less than 25mm between the plumbing fixture,
appliance or appurtenance outlet & the rim of the floor sink or receptor.

INDIRECT WASTE PIPING

 Indirect waste pipes less than 4.6m in length need not to be larger in diameter than the
drain outlet or tailpiece of the fixture or 13mm in diameter min.

INDIRECT WASTE RECEPTORS

 No standpipe receptor for any clotheswasher shall extend more than 8m or less than
0.45m
above its trap.
 Stills, sterilizers & simillar equipment shall be drain through an airgap.

STEAM & HOT WATER DRAINAGE CONDENSERS & SUMPS

 No steam pipe shall be directly connected to any part of a plumbing or drainage system,
nor shall any water having a temperature above 60degrees C be discharged under
pressure directly into any part of a drainage system.
 All condensers & sumps shall be properly trap with a deep sealed trap extending within
152mm at the bottom of the tank.
 Traps shall have 19mm dia. opening to serve as siphon breaker.
 Sumps, condensers or intercepting tanks constructed of concrete shall have:
 Walls & bottom 102mm thickness
 Cement plaster not less than 13mm thickness
 Sumps, condensers or intercepting tanks constructed of metal shall be not less than
No.12
U.S. Standard Gauge (2.77mm thickness)

CHEMICAL WASTES
 Where acid or corrosive chemical is placed & each vent pipe connected thereto, shall be
constructed of chemical-resistant glass-lined pipe, high silicon iron pipe, lead pipe not less
than 3.2mm wall thickness, an approved type of ceramic glazed or unglazed vitrified clay
or other approved corrosion resistant material.

VERTICAL WET PIPING

 Wet venting is limited to vertical drainage piping receiving the discharge from the trap
arm of one (1) & two (2) fixture unit. Fixtures that also serves as a vent for not to exceed four
(4) fixtures.

 Size of wet vent shall be:

  Max. of 1 pipe size larger than the required min. waste pipe size of:
 the upper fixture
 the sum of the fixture units served by such wet-vented section
 Min. 51mm diameter

COMBINATION WASTE & VENT SYSTEMS (CW & VS)

 Shall be permitted only where structural conditions preclude the installation of
conventional systems
 Any branch more than 4.6m in length shall be separately vented
 Min. area of vent shall be 1/2 the inside cross-sectional area of the drain pipe served.
 Min. dia. of traps shall be 2 pipe sizes larger than any fixture, tailpiece or connection.
 In no case any tailpiece or connections shall exceed 0.6m long.

AIR CONDITIONING EQUIPMENT

 19.1mm min. size of condensate wastes pipe
 Air-conditioning condensate waste pipes shall connect indirectly to the drainage
system through an airgap or airbreak.

CHAPTER 9: VENTS AND VENTING

MATERIALS
 Vent Pipes shall be of Cast Iron, Ductile Iron, Galvanized Steel, Galvanized Wrought
Iron, Lead, Copper, Brass, Schedule 40, ABS, DWV, Series 1000 PVC or other approved
materials having smooth & uniform bore except that:
 No Galvanized Wrought Iron or Galvanized Steel Pipe & Fittings shall be used
underground & shall be kept at least 152mm above ground.
 Horizontal & vertical vent lines & vent stacks shall be Copper, Cast Iron, Galvanized
Wrought Iron or Polyvinyl Chloride Pipes.
 Vent Fittings shall be Cast Iron, Galvanized Malleable Iron or Galvanized Steel, Lead,
Copper, Brass, ABS, PVC, Vitrified Clay Pipe or other approved materials having smooth
interior waterway of the same diameter as the piping served.

SIZE OF VENTS
 Shall not be less than 1 1/4 (32mm) nor less than 1/2 the dia. of the drain to which it is
connected.
 The aggregate cross-sectional area shall not be less than the largest required building
sewer.

VENT TERMINATION
 Each vent stack through roof (VSTR) shall:
 extend its flashing all around the stack
 terminate vertically not less than 15cm above the roof
 have a clearance of 0.3m away from any vertical surface nearby
 Each vent opening shall:
 not terminate not less than 3m from or at least 0.9m above any operable window,
door opening, air intake or vent shaft
 at least 0.9m min. away from any lot line, alley & street boundary lines.

VENT STACKS & RELIEF VENTS

 Yoke vent in connection with the vent stack shall be placed not less than 1.0m above
the floor level.
 CHAPTER 10: TRAPS AND INTERCEPTORS

TRAPS REQUIRED
 Not more than 1 traps shall be permitted on a trap arm.
 1 trap may serve:
 3 single compartment sink of the same depth
 3 lavatories immediately adjacent to each other not more than 0.75m apart.
 In no case any tailpiece or connections shall exceed 0.6m long.

TRAP SEALS
 Each fixture trap shall have a water seal of not less than 51mm & not more than 102mm
deep.

INDUSTRIAL INTERCEPTORS (CLARIFIERS) & SEPARATORS

 Shall be so designed & located as to be readily accessible for cleaning & shall have
a water seal of not less than 152mm deep.

GREASE TRAPS
 Shall not be installed for a facility that has an approved rate of flow of greater than 3.4L/sec
& lower than 1.3L/s.
 The total capacity of fixtures discharging to any grease trap shall not exceed 2 1/2
times the certified liters per minute flowrate of grease traps.
 Grease traps may be used as a fixture outlet provided:
 Hor. distance between the fixture & the grease trap does not exceed 1.2m.
 Vertical tailpipe or drain does not exceed 0.75m.
 Grease traps shall have an approved water seal of 51mm min. in depth or the
diameter of its outlet.

SAND INTERCEPTORS
 Shall be have a dimension of 0.2m2 min. for the net free opening of the inlet section & a
610mm min. depth under the invert of the outlet pipe.

CHAPTER 11: STORM DRAINAGE SYSTEM

RAINWATER SYSTEMS
 Rainwater Downspout or Conductor Pipings placed within the interior side of the
building inside a vertical pipe chase or run within a vent shaft shall be of Cast Iron,
Ductile Iron, Galvanized Steel, Iron, Lead, Copper, Brass, Schedule 40, ABS, Series 1000
PVC DWV, or other approved materials.
 Rainwater Downspout or Conductor located on the exterior side of a low height
building shall be not less than Ga. 26 galvanized sheet metal.

ROOF DRAIN
 Strainers
 Should not exceed 102mm above the surface of the roof immediately adjacent
to the drain
 Dome-type strainers shall have at least 1 1/2 times the area of the outlet pipe to
which it is connected.
 Roof Deck strainers shall have at least 2 times the area of the outlet pipe to which
it is connected.
 Vertical Wall Areas
 For 1 wall – add 50% of area of the wall to the roof area
 For 2 adjacent walls – add 35% of the total wall areas to the roof area
 For 2 walls opposite each other & of the same heights – add NO additional area
 Vertical piping may be round, square or rectangular provided that the area of a
rectangular piping shall have at least the equivalent cross sectional area of a circular
piping & its dimensions shall not exceed 3 to 1.
 CHAPTER 12: TRAPS AND INTERCEPTORS

SEWER REQUIRED
 It is considered that public sewer is not available if it is located more than 61m from the
proposed building or exterior drainage facility or any lot or premises thereat.
 Building sewer  beginning 0.6m from outside face of the wall.

SIZE OF BUILDING SEWERS

 Size of any building sewer shall be determined on the basis of the total number of
fixture units drained by such sewer, but in no case size of building sewer shall be less
than 150mm.

GRADE, SUPPORT, & PROTECTION OF BUILDING SEWER

 Grade of building sewers shall not be less than 2%. In special cases where 2% grade
cannot be achieved, it may be reduced but shall not be less than 1%.
 Building sewer shall be installed not less than 0.6m from the outer face of the building,
foundation or wall nor less than 0.3m below the finish surface of the ground.

CLEANOUTS
 Additional building sewer cleanouts shall be installed not to exceed 15m o.c. in straight
runs & each aggregate change in direction exceeding 135degrees.
 No cleanouts will be required when a building sewer or a branch thereof does not
exceed 3m in length.
 Manholes can be installed in lieu of cleanouts & shall be located not exceeding 91m
in between & outlet pipe connections shall be made by the use of flexible compression
joints no closer than 0.3m from outside of the manhole.

SEWER & WATER PIPES

 The bottom of the water pipe, at all points, shall be at least 0.3m above the top of the
sewer or drain line.
 Water pipes constructed of clay or other materials not approved for the use within a
building shall be laid a 0.3m min. clear above the sewer or drain pipe.
 Water pipe joints shall be installed not less than 3m away from sewer line in both directions.

ABANDONED SEWERS & SEWAGE DISPOSAL FACILITIES

 Every abandoned building (house) sewer, or part thereof, shall be plugged or capped
in an approved manner within 1.5m of the property line.
 All drainage piping shall clear domestic water supply wells by at least 15.2m. The
distance may be reduced to not less than 7.6m when the drainage piping is
constructed of materials approved for the use within a building.
 CHAPTER 13: JOINTS AND CONNECTIONS

TYPES OF JOINT
 Caulked joints - for bell-&-spigot Cast Iron Soil (CISP) & other similar joints
shall be firmly packed with oakum or hemp & filled with pig lead to a depth of not less
than 25.4mm.
 Threaded joints - for Iron Pipe Size (IPS) pipe & fittings shall be standard taper
pipe threads. Threaded Plastic Pipe shall be Sch.80 min. wall thickness.
 Wiped joints - joints in lead pipe fittings or between lead pipe or fittings &
brass or copper pipe, ferrules, solder nipples or traps shall be full-wiped lead joints.
Wiped lead joints shall have an exposed surface on each side of a joint not less than
19mm & at least as thick as the material being joined.
 Solder & Sweat joints - joints in copper tubing shall be made by the appropriate use of
approved brass or copper fittings. Solders & fluxes with a lead content which exceeds
0.002 are prohibited in piping systems used to convey potable water.
 Flared joints - for soft copper water tubing
 Cement Mortar joints - except for repairs & connections to existing lines
constructed with such joints such joints prohibited on new building sewers.
 Burned Lead joints - shall be fused together to form a uniform weld at lest thick as the
lead sheets being joined.
 Asbestos Cement Sewer Pipe joints - shall be a sleeve coupling of the same
composition as the pipe or of other approved materials, and sealed with neoprene
rubber rings or joined by approved type compression coupling
 Mechanical joints - shall be for Centrifugal Cast Iron water pipe.
 Molded Rubber Coupling Joints - joined by means of molded neoprene rubber
coupling joints. Neoprene rubber shall be used in soils subject to oil intrussion.
 Elastomeric Gasketed & Rubber-ring Joints - shall conform to IAMPO (International
Association of Plumbing & Mechanical Officials) Installation Standard. Neoprene
gaskets are recommended for oil handling piping works.
 Pressure-Lock Type Connection - a mechanical connection which depends on an
internal retention device to prevent pipe or tubing separation. Connection is made by
inserting the pipe or tubing inside the filling to a prescribed depth.
 Shielded Coupling & Hubless Cast Iron Pipe joints - shall not be considered as slip joints.

USE OF JOINTS
 Clay Sewer pipes - shall be joined with neoprene gasket for hub & spigot joints.
 Screwed Pipe to Cast iron Pipe - shall be either caulked or threaded
 Lead to Cast Iron, Wrought Iron or Steel - shall be by means of wiped joints to
caulking ferrule, soldering nipple or bushing.
 Copper Water Tube - shall be joined by brass fittings properly soldered or brazed together.

SPECIAL JOINTS
 Copper Tubing to Screw Pipe Joints - shall be made by the use of brass adaptor fittings.
Joints between copper tubing & the fittings shall be properly sweated or soldered or
made with flared & screw ends adaptor fittings the connection between the treaded
pipe & the fitting made with a standard pipe size screw joint.
 Slip joints - may be used in fixture drains & traps.
 Expansion joints - used in soil & waste stacks to provide necessary expansion &
contraction joints of the pipes for high-rise buildings.

FLANGED FIXTURE CONNECTIONS

 Gasket Material shall be graphite-impregnated asbestos, felt, or similar approved types.
CHAPTER 14: QUALITY AND WEIGHTS OF MATERIALS, PLUMBING MATERIALS AND REFLECTED
STANDARDS

USE OF COPPER TUBING

 Copper tube shall not be used for piping carrying chemical or industrial wastes

LEAD
 Lead bends & lead traps shall not be less than 3.2mm in wall thickness.

CLOSET RINGS (CLOSET FLANGES)

 Each such closet ring or closet flange shall be approximately 178mm in diameter, when
installed together with the soil pipe, present a 38mm wide flange & a groove face to
receive the fixture gasket or ball wax.
 Caulked-on closet rings or closet flanges shall not be less than 6.4mm thick & not less
than 51 in overall depth.
 Four (4) bolts per water closet.

VALVES & FITTINGS

 Drainage Gate Valves shall be:
 Cast Iron bodies for 102mm or larger
 Cast Brass or Bronze bodies for sizes less than 102mm

REFERENCE SPECIFICATIONS FOR PLUMBING MATERIALS

 AHAM - Association of Home Appliance Manufacturers
 ANSI - American National Standard Institute
 ASME - American Society of Mechanical Engineers
 ASSE - American Society of Sanitary Engineers
 AWWA - American Water Works Association
 CISPI - Cast Iron Soil Pipe Institute
 CS & PS - Commercial Standards & Product Standards
 FS - Federal Specifications
 IAPMO - International Association of Plumbing & Mechanical Officials
 PDI - Plumbing & Drainage Institute
 PNS- Philippine National Standard Certification Mark
 UL - Underwriter’s Laboratories, Inc.
 WQA - Water Quality Association
 ISO - International Standard Organization
 EN - European Committee for Standardization Central Secratariat

PLUMBING MATERIALS
 ABS- Acrylonitrile-Butadine-Styrene
 DWV - Drain, Waste & Vent
 CPVC - Chlorinated Polyvinyl Chloride
 UPVC - Unplasticized Polyvinyl Chloride
 CPE- Chlorinated Polyethylene
APPENDIX A: RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYSTEM

GENERAL
 Velocities shall not exceed 3m/sec of the maximum values given in the appropriate
installation standard.
 Allowances in Equivalent Length of Pipe shall be based on non-recessed threaded
fittings. For recessed threaded fittings or streamline solder fittings, use 1/2 the
allowances.

DEMAND WEIGHT OF FIXTURES IN WATER SUPPLY FIXTURE UNITS

 The weights for maximum separate demands may be taken as 75% of the demand
for supply.

APPENDIX B: PRIVATE SEWAGE DISPOSAL SYSTEMS

GENERAL
 Where permitted by the rules & regulations of the Department of Environment &
Natural Resources (DENR). The building sewer may be connected to a private sewage
disposal system & shall be determined:
 Basis of location
 Soil porosity
 Ground water level
The system shall consist of a septic tank with effluent discharging into a subsurface
disposal field, into one (1) or more seepage pits or into a combination of subsurface
disposal field & seepage pits.

CAPACITY OF SEPTIC TANKS

 The capacity of any one septic tank & its drainage system shall be limited by the soil
structure classification.

AREA OF DISPOSAL FIELDS & SEEPAGE PITS

 When disposal fields are installed, it shall have:
 Minimum of 14m2 of trench bottom shall be provided for each system
 Side wall area of the required 304.8mm & not to be exceed 914.4mm below leach
line
 When leaching beds are permitted in lieu of trenches:
 The area of each such bed shall be at least 50% greater than the tubular
requirements for trenches.
 Side wall area of the required 304.8mm & not to be exceed 914.4mm below leach
line
 No excavation for a leach line or leach bed shall extend within 1.5m of the water table.
 No excavation for a seepage pit shall extend within 3m of the water table.

SEPTIC TANK CONSTRUCTION

 Septic tanks shall have a min. of 2 compartments
 Inlet compartment of any septic tank shall not be less than 2/3 of the total capacity of
the tank.
 Secondary compartment of any septic tank shall have a min. capacity of 1m3 & max.
capacity of 1/3 the total capacity of the tank.
 0.9m x 1.5m Min. dimension

 0.6m min & 1.8m max. depth

 Septic tanks having over 6m3 capacity, secondary compartment of such septic tank
shall have a min. 1.5m length.
 Septic tanks shall have a min. of 2 manholes with 508mm min. dimension
 Whenever a first compartments exceeds 3.7min length, additional manhole shall be
provided.
 Size of the vertical leg of a round inlet & outlet fittings shall not be less than the size of the
connecting sewer nor less than 104.6mm. a baffle type fitting shall not be less than the
size of the connecting sewer nor less than 106.6mm hor. dimension from inlet & outlet pipe
inverts.

 The inlet & outlet pipe or baffle shall extend 101.6mm above & at least 304.8mm below
the water surface. The invert of the inlet pipe shall be at level not less than 50.8mm above
 the invert of the outlet pipe.
 Side walls shall extend at least 228.6mm above the liquid depth. The cover of the septic
tank shall be at least 50.8mm above the back vent openings.
 Partitions or baffles between compartments shall be of solid durable material & shall
extend at least 101.6mm above the liquid level.

CONCRETE SEPTIC TANKS

 Shall have bituminous coating or by other approve means extending at least 101.6mm
below the water line.

STEEL SEPTIC TANKS

 Shall have a of No.12 U.S. Ga. (2.8mm) min. thickness & shall have bituminous coating
or by other approve means extending at least 101.6mm below the water line.

DISPOSAL FIELDS
 When seepage pits are used in combination with disposal fields, the filter material in
trenches shall terminate at least 1.5m from the pit excavation.
 The inverts of all outlets shall be level & the invert of the inlet shall be at least 25.4mm
above the outlets.

SEEPAGE PITS
 Shall be circular in shape & shall have an excavated diameter of 2.2m min.
 Shall have a sidewall of 3m min. below inlet.
 Concrete slab covering of 127mm min. thickness.
 228.6mm min. inspection hole.

CESSPOOLS
 May be installed for single family dwellings where it is established that a public sewer
system will be available in less than two (2) years.
 Shall have a sidewall of 3m min. below inlet provided a strata of gravel or equally
pervious material of 1.2m in thickness is found therein. But in cases without such
conditions, sidewall may be increased to 6.1m min. below the inlet.

COMMMERCIAL or INDUSTRIAL SPECIAL LIQUID WASTE DISPOSAL

 Interceptors shall have not less than two (2) compartments.