SPECIFICATION: ALUMINUM SLIDE & WEIR GATES
PART 1 GENERAL
SCOPE OF WORK
The CONTRACTOR shall furnish all labor, materials, equipment and incidentals
required to install, ready for operation and field test stainless steel gates and
appurtenances as shown on the Contract Drawings and as specified herein.
The gates and appurtenances shall be supplied in accordance with the latest edition of
AWWA C562 Standard for Fabricated Aluminum Slide Gates as modified herein.
REFERENCES
AWWA C562 Fabricated Aluminum Slide Gates
ASTM A240 Stainless and Heat Resisting Plate
ASTM A276 Stainless and Heat Resisting Steel Bars and Shapes.
ASTM B584 Copper Alloy Sand Castings
ASTM B209 Aluminum Plate
ASTM B221 Aluminum Bars and Shapes
ASTM B308 Aluminum Structural Profiles
ASTM D2000 Rubber Products in Automotive Applications
ASTM D4020 Ultra-High Molecular Weight Polyethylene
ASTM F593 Stainless Steel Bolts, Hex Cap Screws and Studs
ASTM F594 Stainless Steel Nuts
AWS D1.2 Structural Welding Code - Aluminum
AWS D1.6 Structural Welding Code – Stainless Steel
SUBMITTALS
Provide the following information to confirm compliance with the specification in
addition to the submittal requirements specified in Section .
Complete description of all materials including the material thickness of all
structural components of the frame and slide.
General assembly drawings showing all details of construction, details required for
installation, dimensions, and anchor bolt locations. General assembly drawings
must be provided in 3D format.
Maximum bending stress and deflection of the slide under the maximum design head.
Calculations for maximum operating load, hoist selection, and stem design.
QUALITY ASSURANCE/QUALIFICATIONS
All of the equipment specified under this Section shall be furnished by a single
manufacturer with a minimum of 20 years experience designing and manufacturing
water control gates. The manufacturer shall have manufactured water control gates for a
minimum of 100 projects.
The manufacturer’s shop welds, welding procedures, and welders shall be qualified
and certified in accordance with the requirement of the latest edition of ASME,
Section IX or AWS D1.2 Structural Welding Aluminum.
The specification is based on the aluminum slide gate as manufactured by Rodney
Hunt, Inc of Orange, MA.
PART 2 EQUIPMENT
GENERAL
Each slide gate will be manufactured as detailed here and will be supplied fully
tested as per requirements. To the maximum extent possible, the gate assembly
comprising of frame, guides and slide will be supplied as a factory assembled unit
and shipped to site ready to install on the wall thimble or wall.
The aluminum slide gates will be manufactured in accordance with AWWA
C-562.
The gate manufacturer will be
Rodney Hunt, Inc.
or prior approved equal.
The slide gates will be designed for water tightness for both seating and
un-seating differential head per the actual site requirement as detailed in
the Aluminum Slide Gate Table.
The slide gates will be shop tested to verify the leakage performance at
operating head in the un-seating direction. Where sealing configuration
permits, hydrostatic testing will be conducted at 1.5 times operating head,
to demonstrate structural integrity. Testing for opening load at the
unseating operating head to verify actuating mechanism sizing will also be
conducted.
The slide gates will be of rising stem type unless site geometry prohibits it.
Operation will be by means of a manual hoist, electric actuator or hydraulic
cylinder as detailed in the Stainless Steel Slide Gate Table.
The slide gate will be supplied complete with all accessories such as: gate
assembly, gasket, studs and nuts for mounting, stem, thrust nut, stem
couplings, stem guides, pedestal, operating mechanism as required, gate
opening indicating arrangement and as required anchor bolts and fasteners
for stem guides and pedestal.
The allowable leakage rate for the aluminum gates in this specification shall be
1/2 the allowable leakage listed in the latest revision of AWWA C562, 0.05
gpm/ft of wetted seal perimeter in seating head and unseating head conditions.
The gates shall utilize self-adjusting seals. Due to the difficulty of accessing
gates when they are in service - gates that utilize adjustable wedges, wedging
devices or pressure pads are not acceptable.
All structural components of the frame and slide shall be fabricated of
aluminum having a minimum thickness of 1/4-inch and shall have adequate
strength to prevent distortion during normal handling, during installation and
while in service.
All welds shall be performed by welders with AWS certification for the material
grades used in fabrication.
Finish: Mill finish on aluminum. Welds shall be cleaned by buffing or brushing.
Aluminum in contact with concrete or cementitious grout shall be coated with
epoxy paint to provide isolation. All iron and steel components shall be properly
prepared and shop coated with a primer.
FRAME
The frame assembly, including the guide members, invert member and yoke
members, shall be constructed of shapes with a minimum thickness of 1/4-inch for
all wetted members.
Frame design shall allow for embedded mounting, mounting directly to a wall
with stainless steel anchor bolts and grout or mounting to a wall thimble with
stainless steel mounting studs and a mastic gasket material. Mounting style
shall be as shown on the Contract Drawings.
All wall mounted or wall thimble mounted gates shall have a flange frame. Flat
frame gates are not acceptable.
Gussets shall be provided as necessary to support the guide members in an
unseating head condition.
The frame shall extend to accommodate the entire height of the slide when the
slide is in the fully opened position on upward opening gates or downward
opening weir gates.
On self-contained gates, a yoke shall be provided across the top of the frame.
The yoke shall be formed by a structural members affixed to the top of the side
frame members to provide a one-piece rigid assembly. The yoke shall be
designed to allow removal of the slide.
A rigid aluminum invert member shall be provided across the bottom of the
opening. The invert member shall be of the flush bottom type on upward
opening gates.
A rigid aluminum top seal member shall be provided across the top of the
opening on gates designed to cover submerged openings.
A rigid aluminum member shall be provided across the invert of the
opening on downward opening weir gates.
SLIDE
The slide and reinforcing stiffeners shall be constructed of aluminum plate and
shapes. All structural components shall have a minimum thickness of 1/4-inch.
The slide shall not deflect more than 1/360 of the span or 1/16 inch, whichever
is smaller, under the maximum design head.
Reinforcing stiffeners shall be stitch welded to the slide and mounted
horizontally. Vertical stiffeners shall be welded on the outside of the horizontal
stiffeners for additional reinforcement.
The stem connector shall be constructed of two angles or plates. The stem
connector shall be continuously welded to the slide. A minimum of two bolts shall
connect the stem to the stem connector.
SEALS
All gates shall be provided with a self-adjusting seal system to restrict leakage in
accordance with the requirements listed in this specification.
All gates shall be equipped with UHMW polyethylene seat/seals to restrict
leakage and to prevent metal to metal contact between the frame and slide.
The seat/seals shall extend to accommodate the full height of the slide in all
positions.
All upward opening gates shall be provided with a resilient seal to seal the
bottom portion of the gate. The seal shall be attached to the invert member or
the bottom of the slide and it shall be held in place with stainless steel
attachment hardware.
All downward opening weir gates shall be provided with UHMW polyethylene
seat/seals across the invert member.
The seal system shall be durable and shall be designed to accommodate high
velocities and frequent cycling without loosening or suffering damage.
All seals must be bolted or otherwise mechanically fastened to the frame or slide.
The seals shall be mounted so as not to obstruct the water way opening.
Gates that utilize rubber “J” seals or “P” seals are not acceptable.
The seal system shall have been factory tested to confirm negligible wear (less
than 0.01”) and proper sealing. The factory testing shall consist of an accelerated
wear test comprised of a minimum of 25,000 open-close cycles using a well-
agitated sand/water mixture to simulate fluidized grit.
OPERATING STEM
The slide gates will be supplied with rising type operating stems unless non-rising stems
are required by installation geometry.
The stem will be supplied with ACME full or stub threading. The stem will be
designed to allow for elevation deviations of up to 2”.
The stem shall be constructed of solid stainless-steel bar for the entire length, the
metal having a tensile strength of not less than 90,000 psi for stems that are 3
inches or less in diameter. Stems that are in excess of 3 inches in diameter shall
have a tensile strength of 85,000 psi.
The threaded portion of the stem shall have a minimum outside diameter of 1-1/2
inches. Stem extension pipes are not acceptable.
The design of stem will be per the provision in AWWA C-562.
The L/r ratio will not exceed 200.
For buckling, Euler’s formula will be used with an end condition of 2.0. For
threaded sections, the radius of gyration will be based on the minor diameter. At
the stem design load as follows, the yield strength of the material will not be
exceeded.
As a minimum for manual hoists, the stem design load is the load produced with a
100 pound effort on the crank or handwheel.
For electric actuators, the stem design load is the greater of the load produced with
a 100 pound handwheel effort and 1.50 times the load produced at a locked rotor
condition.
For hydraulic actuation, the stem design load will be 1.25 times the thrust produced
at system relief pressure.
Stems of more than one section shall be joined by stainless steel or bronze
couplings. The coupling shall be threaded and bolted to the stems.
Stems shall be provided with adjustable stop collars to prevent over closing of the
slide.
STEM GUIDES
Stem guides will be provided as required to meet the stem design criteria.
Wall mounted stem guides will be adjustable in two directions, providing at least
0.50” of adjustment in both directions. Wall brackets will be stainless steel.
Wall mounted stem guides will have machine bored, split bushings to facilitate
erection. Bushings will be bronze or UHMWPE. Stem guides mounting at the base
of the pedestal do not require adjustment.
MANUAL OPERATOR MECHANISMS
Unless otherwise shown on the Drawings, gates shall be operated by a manual
handwheel or a manual crank-operated gearbox. The operator shall be mounted on the
yoke of self-contained gates or on the pedestal of non-self-contained gates.
The gate manufacturer shall select the proper gear ratio to ensure that the gate
can be operated with no more than a 40 lb. effort when the gate is in the closed
position and experiencing the maximum operating head.
An arrow with the word “OPEN” shall be permanently attached or cast onto the
operator to indicate the direction or rotation to open the gate.
Handwheel operators shall be fully enclosed and shall have a cast aluminum or ductile
iron housing.
Handwheel operators shall be provided with a threaded cast bronze lift nut to
engage the operating stem.
Handwheel operators shall be equipped with roller bearings above and below
the operating nut.
Positive mechanical seals shall be provided above and below the operating
nut to exclude moisture and dirt and prevent leakage of lubricant out of the
hoist.
The handwheel shall be removable and shall have a minimum diameter of 15
inches.
Crank-operated gearboxes shall be fully enclosed and shall have cast aluminum or
ductile iron housing.
Gearboxes shall have either single or double gear reduction depending upon
the lifting capacity required.
Gearboxes shall be provided with a threaded cast bronze lift nut to engage
the operating stem.
Bearings shall be provided above and below the flange on the operating nut
to support both opening and closing thrusts.
Gears shall be steel with machined cut teeth designed for smooth operation.
The pinion shaft shall be stainless steel and shall be supported on ball or
tapered roller bearings.
Positive mechanical seals shall be provided on the operating nut and the pinion
shafts to exclude moisture and dirt and prevent leakage of lubricant out of the
hoist.
The crank shall be cast aluminum or cast iron with a revolving nylon grip.
The crank shall be removable.
All gates having widths in excess of 72 inches and widths greater than twice their
height shall be provided with two gearboxes connected by an interconnecting shaft for
simultaneous operation.
Interconnecting shafting shall be constructed of aluminum or stainless steel.
Flexible couplings shall be provided at each end of the interconnecting shaft.
One crank shall be provided to mount on the pinion shaft of one of the gearboxes.
An extended operator system utilizing chain and sprockets shall be furnished by the
manufacturer when the centerline of the crank or handwheel, on a non-geared
operator, is located over 48 in above the operating floor. Chain wheels are not
acceptable.
A removable stainless steel or aluminum cover shall be provided to enclose
chain and sprockets.
The extended operator system shall lower the centerline of the pinion shaft to
36 in above the operating floor.
A handwheel may be utilized in conjunction with a gearbox in lieu of the
extended operator system if the centerline of the pinion shaft is 60 in or less
above the operating floor.
Pedestals shall be constructed of stainless steel. Aluminum pedestals are not acceptable.
The pedestal height shall be such that the handwheel or pinion shaft on the
crank-operated gearbox is located approximately 36 in above the operating
floor.
Wall brackets shall be used to support floor stands where shown on the
Drawings and shall be constructed of stainless steel.
Wall brackets shall be reinforced to withstand in compression at least two times
the rated output of the operator with a 40 lb. effort on the crank or handwheel.
The design and detail of the brackets and anchor bolts shall be provided by the
gate manufacturer and shall be approved by the ENGINEER. The gate
manufacturer shall supply the bracket, anchor bolts and accessories as part of
the gate assembly.
Operators shall be equipped with polycarbonate plastic stem covers.
The top of the stem cover shall be closed and vented. Gate opening indication will
be provided on the stem cover for all non-rising stem gates. A full height scale will
be mounted on the side of the stem cover and an indicator nut mounted on the
rising stem to show gate position. The scale graduation will be 1”.
The bottom end of the stem cover shall be mounted in a housing or adapter for
easy field mounting.
When shown on the Contract Drawings, provide 2-inch square nut, mounted
in a floor box, with a non-rising stem.
The square nut shall be constructed of stainless steel.
The floor box shall be constructed of stainless steel or cast iron and shall be set in
the concrete floor above the gate as shown.
Provide one aluminum or stainless-steel T-handle wrench for operation.
ELECTRIC MOTOR ACTUATORS
See Section .
WALL THIMBLES
Wall thimbles shall be provided when shown on the Contract Drawings.
The wall thimble depth shall be equal to the thickness of the concrete wall in
which the thimble is to be mounted.
Wall thimbles shall be fabricated stainless steel construction of adequate
section to withstand all operational and reasonable installation stresses.
Wall thimbles shall be constructed of 1/4-inch minimum thickness stainless
steel and the front face shall have a minimum thickness of 1/4–inch.
The fabrication process shall ensure that the wall thimble is square and plumb
and the front face is sufficiently flat to provide a proper mounting surface for the
gate frame.
The face of the wall thimble shall only be machined if recommended by the
gate manufacturer. If the wall thimble is to be machined, the front face
shall have a minimum thickness of 1/4-inch after machining.
A water stop shall be welded around the periphery of the thimble. Wall
thimbles shall be designed to allow thorough and uniform concrete placement
during installation.
Studs and nuts shall be stainless steel. Water stop may be stitch welded.
A suitable gasket or mastic shall be provided to seal between the gate frame
and the wall thimble. Electrical isolation between the thimble and gate frame
shall be provided.
ANCHOR BOLTS
Anchor bolts shall be provided by the gate manufacturer for mounting the
gates and appurtenances.
Quantity and location shall be determined by the gate manufacturer.
If epoxy type anchor bolts are provided, the gate manufacturer shall provide
the studs and nuts.
Anchor bolts shall have a minimum diameter of 1/2-inch.
PART 3 MATERIAL OF CONSTRUCTION
Frame Assembly Aluminum ASTM B209, B221, B308 T6061-T6
Slide and Stiffeners Aluminum ASTM B209, B221, B308 T6061-T6
Stem Stainless Steel, ASTM A276 Type 304 or
Stainless Steel, ASTM A276 Type 316
Wall Thimble Stainless Steel, ASTM A276 Type 304L or
Stainless Steel, ASTM A276 Type 316
Fasteners ASTM F593 and F594 GR1 for type 304
ASTM F593 and F594 GR2 for type 316
Anchor Bolts Stainless Steel, ASTM A276 Type 304 or
Stainless Steel, ASTM A276 Type 316
Invert Seal Neoprene or EPDM ASTM D-2000
(Upward Opening Gates Only)
Seat/Seals and Facing Ultra-High Molecular Weight Polyethylene
ASTM D4020
Lift Nuts Bronze ASTM B584 - C865
Pedestals and Stainless Steel, ASTM A276 Type 304L or
Wall Brackets Stainless Steel, ASTM A276 Type 316L
Operator Housing Cast Aluminum or Ductile Iron
PART 4 EXECUTION
INSTALLATION
Installation of the gates and appurtenances shall be done in a workmanlike manner. It
shall be the responsibility of the CONTRACTOR to handle, store and install the
equipment specified in this Section in strict accordance with the manufacturer’s
recommendations.
The CONTRACTOR shall review the installation drawings and installation
instruction prior to installing the gates.
The gate assemblies shall be installed in a true vertical plane, square and plumb.
The CONTRACTOR shall fill the void in between the gate frame and the wall with non-
shrink grout as shown on the installation drawing and in accordance with the
manufacturer’s recommendations.
The CONTRACTOR shall add a mastic gasket between the gate frame and wall
thimble (when applicable) in accordance with the manufacturer’s
recommendations.
FIELD TESTING
After installation, all gates shall be field tested in the presence of the ENGINEER and
OWNER to ensure that all items of equipment are in full compliance with this Section.
Each gate shall be cycled to confirm that they operate without binding, scraping, or
distorting.
The effort to open and close manual operators shall be measured and shall not exceed
the maximum operating effort specified above. Electric motor actuators shall function
smoothly and without interruption.
Each gate shall be water tested by the CONTRACTOR, at the discretion of the
ENGINEER and OWNER, to confirm that leakage does not exceed the specified
allowable leakage.
