Engineering Standard
SAES-L-110 30 March 2005
Limitations on Pipe Joints and Components
Piping Standards Committee Members
Al-Sannaa, M.S., Chairman
Al-Dossary, M.B.
Al-Nasri, N.I.
Al-Qahtani, K.D.
Al-Sabti, R.A.
Al-Sharif, T.M.
Al-Teraiki, A.M.
Balhareth, N.M.
Chen, J.T.
Fadley, G.L.
Ismail, A.A.
Khashab, J.M.
Kim, S.U.
Lewis, T.
Mahmoud, K.A.
Mullen, M.A.
Phan, H.C.
Solaiman, M.Z.
Stark, G.D.
Saudi Aramco DeskTop Standards
Table of Contents
1 Scope............................................................. 2
2 Conflicts and Deviations................................ 2
3 References..................................................... 2
4 Definitions...................................................... 4
5 Welded Joints................................................ 5
6 Prohibited Piping Joints and Components..... 6
7 Threaded Joints............................................. 6
8 Seal Welding of Threaded Joints................... 7
9 Pipe Fittings General Requirements.............. 8
10 Threaded and Socket Welding Fittings.......... 8
11 Steel Butt Welding Fittings............................. 9
12 Branch Connection Fittings.......................... 9
Previous Issue: 30 September 2003 Next Planned Update: 1 October 2008
Revised paragraphs are indicated in the right margin Page 1 of 12
Primary contact: Muhsen S. Al-Sannaa on 874-6679
Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
13 Specialty and Proprietary Couplings............ 10
1 Scope
1.1 This Standard covers the limitations on various types of piping joints and
components used in metallic piping for pressure piping systems within the
context of SAES-L-100.
1.2 This Standard covers additional requirements to ASME B31.1, B31.3, B31.4
and B31.8 piping codes and defines requirements governing the selection of
metallic pipe fittings, bends, miters, laps, and branch connections for plant
piping and pipelines. Tube fittings and other specialty fittings are outside the
scope of this standard.
1.3 Bolted flange joints are excluded from this standard and shall be in accordance
with SAES-L-109.
2 Conflicts and Deviations
2.1 Any conflicts between this standard and other applicable Saudi Aramco
Engineering Standards (SAESs), Materials System Specifications (SAMSSs),
Standard Drawings (SASDs), or industry standards, codes, and forms shall be
resolved in writing by the Company or Buyer Representative through the
Manager, Consulting Services Department (CSD) of Saudi Aramco, Dhahran.
2.2 Direct all requests to deviate from this standard in writing to the Company or
Buyer Representative, who shall follow internal company procedure SAEP-302
and forward such requests to the Manager, Consulting Services Department of
Saudi Aramco, Dhahran.
3 References
The selection of material and equipment, and the design, construction, maintenance, and
repair of equipment and facilities covered by this standard shall comply with the latest
edition of the references listed below, unless otherwise noted.
3.1 Saudi Aramco References
Saudi Aramco Engineering Procedure
SAEP-302 Instructions for Obtaining a Waiver of a
Mandatory Saudi Aramco Engineering
Requirement
Saudi Aramco Engineering Standards
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
SAES-A-301 Materials Resistant to Sulfide Stress Corrosion
Cracking
SAES-B-017 Fire Water System Design
SAES-L-100 Applicable Codes and Standards for Pressure
Piping Systems
SAES-L-101 Regulated Vendor Lit for Pipes, Fittings and
Gaskets
SAES-L-109 Selection of Flanges, Stud Bolts and Gaskets
SAES-L-136 Pipe Selection and Restrictions
SAES-L-350 Construction of Plant Piping
SAES-W-011 Welding Requirements for On-plot Piping
SAES-W-012 Welding Requirements for Pipelines
SAES-W-013 Welding Requirements for Offshore Structures
Saudi Aramco Materials System Specifications
02-SAMSS-001 Piping Components for Low Temperature Service
02-SAMSS-005 Butt Welding Pipe Fittings
Saudi Aramco Standard Drawings
AD-036090 Joints for Welding Cement Lined Pipe
AE-036175 Detail of Welding Boss, Threaded Connection to
Vessels and Lines
AC-036404 Flame Impingement Shield for Flangeless Valve
AE-036643 Heavy Welding Boss, Socket Weld Connections
3.2 Industry Codes and Standards
American Petroleum Institute
API SPEC 6A Wellhead and Christmas Tree Equipment
API STD 602 Compact Steel Gate Valves - Flanged, Threaded,
Welding, and Extended-Body Ends
American Society of Mechanical Engineers
ASME B16.11 Forged Steel Fittings, Socket-Welding and
Threaded
ASME B1.20.1 Pipe Threads, General Purpose (Inch)
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
ASME B16.25 Buttwelding Ends
ASME B16.3 Malleable Iron Threaded Fittings
ASME B31.1 Power Piping
ASME B31.3 Process Piping
ASME B31.4 Pipeline Transportation Systems for Liquid
Hydrocarbons and Other Liquids
ASME B31.8 Gas Transmission and Distribution Piping
Systems
ASME SEC VIII D2 Pressure Vessels, Alternative Design
American Society for Testing and Materials
ASTM A105 Standard Specification for Carbon Steel Forgings
for Piping Applications
ASTM A182 Standard Specification for Forged or Rolled
Alloy-Steel Pipe Flanges, Forged Fittings, and
Valves and Parts for High-Temperature Service
ASTM A350 Standard Specification for Carbon and Low-Alloy
Steel Forgings, Requiring Notch Toughness
Testing for Piping Components
Manufacturers Standardization Society
MSS SP-75 Specification for High Test Wrought Butt Welding
Fittings
MSS SP-83 Steel Pipe Unions, Socket-Welding and Threaded
4 Definitions
Definitions per SAES-L-100 shall apply.
Metal to Metal Seal Joint: A joint that relies on the mechanical fit between metals to
seal against pressure.
Proprietary Coupling: A joint that is developed and possibly patented by a particular
firm and could be not covered by any Industry Code.
Specialty Coupling: A joint that is not covered by any Industry Code.
LokRing: It is a proprietary coupling used to join two pipes together. It relies on the
mechanical grip between the pipe (female) and the joint (male).
Page 4 of 12
Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
Positive Seal Coupling: It is a proprietary coupling used to join two pipes together. It
relies on the mechanical grip between the pipe (male) and the joint (female).
5 Welded Joints
5.1 Pipe Welds
Welds in metallic piping shall conform to the requirements to the applicable
welding standard which are SAES-W-011, SAES-W-012 and SAES-W-013 and
other Standards referenced therein.
5.1.1 When wall thickness ratio of joined pipes is less than or equal to 1.5,
joint design details shall comply with the respective ASME B31 design
code.
5.1.2 When wall thickness ratio of joined pipes greater than 1.5, end
preparations and geometry shall comply to ASME B16.25 "Butt
Welding Ends".
5.1.3 For all four piping codes stated in paragraph 5.1.2 above, refer to
Figure 434.8.6(a)-(2) in ASME B31.4 or Figure 15 in ASME B31.8 for
graphic details of joint designs.
5.1.4 When the wall thickness of the fitting or pipe at the welding end
exceeds the wall thickness of the matching pipe resulting in an unequal
external and/or internal diameters, the welded joint design shall
comply with Fig. 434.8.6(a)-(2) of ASME B31.4 (regardless of the
design code).
5.2 Socket Welds
5.2.1 The maximum size of socket-welded joints in hazardous services shall
be 1½-inch for new construction. Maximum 2-inch may be used in
hazardous service for maintenance, minor field modifications of
existing piping systems, and when necessary to match existing
equipment connections.
5.2.2 For sour service, socket-welded joints should be avoided. In case they
could not be avoided the maximum size of socket-welded joints shall
be 1-inch.
Generally, socket welded joints should be avoided in any service where
crevice corrosion, severe erosion, or cyclic loading may occur.
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
5.2.3 The axial gap between male and female component, as shown in
Figure 328.5.2C of ASME B31.3 code, shall be maximum of 3 mm
and minimum of 1.5 mm. This gap is required prior to welding.
Commentary Note:
This axial gap requirement is only applicable to new installation of
socket welds for new construction, maintenance and modification. It
does not apply to piping already installed and welding was completed
successfully.
5.3 Fillet Welds
The use of sleeve couplings per Standard Drawing AD-036090 shall be limited
to cement lined pipe in water services such as fire fighting piping systems and
oily water service.
6 Prohibited Piping Joints and Components
The following piping components are not allowed and shall not be used in pressure
piping system within the scope of SAES-L-100.
a) Caulked joints.
b) Soldered, brazed, and braze-welded joints.
c) Expanded joints: They are slip on type of joints using O-ring to seal the pressure.
7 Threaded Joints
7.1 The thread standard shall be taper pipe thread (NPT) conforming to ASME
B1.20.1 unless otherwise required by specifications for specific connections.
Threaded connections for fire services are exempted and shall be in accordance
with SAES-B-017.
Generally, threaded joints should be avoided in any service where crevice
corrosion, severe erosion, or cyclic loading may occur.
7.2 In hazardous services, the maximum size of threaded connections shall be
1½-inch for standard fittings and valves, and 2-inch maximum when required
for maintenance, minor field modifications of existing piping systems, and to
match threaded specialty devices such as scraper signals and access fittings for
corrosion monitoring.
7.3 In non-hazardous services, the maximum size of threaded connections shall be
3-inch for standard fittings and valves, and 4-inch maximum on special items
such as fire hydrants unless a larger size is approved by the assigned Chairman,
Piping Standards Committee for the specific application.
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
7.4 The minimum length of the engaged threads pipe shall meet the requirements of
ASME B1.20.1 for taper pipe thread. The minimum number of engaged pipe
threads shall meet the requirements of Table 1.
Table 1 – Thread Engagement Requirements for Taper Pipe Threads
Number of
Nom. Pipe Size
Threads Engaged
1/2" & 3/4" 6
1" through 1-1/2" 7
2" through 3" 8
4" 10
7.5 PTFE (Teflon) tape shall not be used for service temperature greater than 204°C
on threaded connections.
8 Seal Welding of Threaded Joints
8.1 Seal welding of threaded joints is required when deemed necessary by the
Operating Organization for those locations and services where an uncontrolled
leakage would result in serious consequences for the operation or safety of plant
and personnel.
8.2 Seal welding of all threaded joints up to the first block valve is required in the
following services and applications:
a) All hydrocarbons.
b) Boiler feed water, condensate, and steam systems utilizing ASME Class
300 and higher flange ratings.
c) Toxic materials such as chlorine, phenol, hydrogen sulphide, etc.
d) Corrosive materials such as acid, caustic, etc.
e) Oilfield chemicals (e.g., corrosion inhibitors, emulsifiers, electrolytes, etc.)
f) Piping which is subject to vibration, whether continuous or intermittent
8.3 Seal welding is not required for the following services and applications:
a) Thermowells
b) Bar stock plugs downstream of a seal-welded block valve.
c) Special devices such as access fittings and scraper signals.
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
d) Joints which require frequent disassembly and are located downstream of a
seal welded block valve, e.g., sample connections.
e) Instrument piping downstream of the primary instrument isolation valve.
f) Pipe union ring threads and joints with elastomer o-rings.
g) Threaded joints, downstream of a seal welded root valve, which discharge
directly to an open drainage system or to the atmosphere.
h) Extended body valves with integrally reinforced welding end per
API STD 602.
8.4 Where seal welding is required, the seal weld shall be a fillet weld going from
the outer diameter of the female part, and it should be smooth with slight
concavity as allowed by ASME B31, to the male part covering all exposed
threads without undercut.
8.5 PTFE (Teflon) tape or joint compounds shall not be used in threaded
connections requiring seal welding.
9 Pipe Fittings General Requirements
9.1 All metallic pipe fittings shall be fully compatible with the adjoining pipe and
shall be subject to the limitations of SAES-L-136 for carbon steel line pipe.
9.2 The pipe fittings shall be sourced from an approved manufacturer per
SAES-L-101.
9.3 Carbon steel fittings shall be in accordance with the requirements of
02-SAMSS-005.
9.4 For service with design minimum temperature between minus 18°C to minus
45°C, the fittings shall comply with additional requirements of 02-SAMSS-001.
10 Threaded and Socket Welding Fittings
10.1 For steel piping in hazardous services, threaded and socket welding fittings shall
conform to ASME B16.11 Class 3000, Class 6000 or higher.
10.2 Pipe unions in hazardous services shall be limited to Class 3000 threaded or
socket welding forged steel unions in accordance with MSS SP-83. The
material shall be carbon steel per ASTM A105, ASTM A350 or alloy steel per
ASTM A182.
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
10.3 Threaded bushings with one size reduction shall not be used. When bushings
are allowed, only hex head steel bushings shall be used. Flush steel bushings are
not permitted.
10.4 Welding bosses shall be forged steel ASTM A105, ASTM A350 or
ASTM A182, as applicable, as shown on Standard Drawings AE-036175 or
AE-036643.
10.5 Integrally reinforced welding outlets of approved design (such as Weldolets,
Threadolets, Sockolets, etc.) in Class 3000, 6000 or higher, as applicable, which
abut the pipe wall with a full penetration weld are acceptable.
10.6 Malleable iron screwed fittings shall conform to ASME B16.3 Class 150 and
shall be galvanized and limited to non-hazardous services, except that pipe
unions shall be Class 300.
10.7 Pipe plugs for use in metallic piping shall be solid body, bar-stock, or forged
steel plugs in accordance with ASME B16.11.
11 Steel Butt Welding Fittings
11.1 The material and purchasing requirements of carbon steel buttweld fittings to:
ASTM A234 Grade WPB and MSS SP-75 shall conform to the requirements of
02-SAMSS-005.
11.2 Steel butt welding fittings shall conform to 02-SAMSS-005.
11.3 Integrally reinforced welding outlets not listed in SAMS Catalog shall be of a
design approved by the Chairman of the Piping Standards Committee. Refer to
SAES-L-350 for post weld heat treatment requirements for welding outlets.
11.4 Miter elbows are not permitted. In case miter bends have to be used prior
approval by the Chairman of the Piping Standards Committee is required.
12 Branch Connection Fittings
12.1 Selection of the branch connections type and fittings shall be as follows:
12.1.1 For new construction of metallic piping selection shall be made in
accordance with the Chart 1.
12.1.2 In case a branch connection with reinforcement has been selected, the
size of the reinforcement pad shall be per the applicable code.
12.1.3 For field modifications to existing piping, the branch connections as
shown on SASD AB-036719 with proper reinforcement are acceptable.
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
12.2 Laterals, Y-branches, and crosses shall be designed for a bursting strength at
least equal to the calculated bursting strength of the adjoining pipe. The use of
reinforcement other than specified in the Code, such as straps, gussets, brackets
or horseshoes shall be subject to approval by the Chairman of Piping Standards
Committee.
12.3 Branch connections, such as those for drain and vent connections, on tees,
elbows and reducers are not permitted. When not avoidable, the piping design
shall be reviewed and approved by the Chairman of Piping Standards
Committee.
13 Specialty and Proprietary Couplings
13.1 Any new proprietary or specialty mechanical joints regardless of service shall be
evaluated and approved by the Chairman of Piping Standards Committee, prior
to specification and installation. Examples are Victaulic couplings and Dresser
couplings.
13.2 Metal to Metal Seal Coupling
The following proprietary pipe couplings are acceptable within the limitations
specified for each one:
13.2.1 Positive Seal Coupling
The use of Positive Seal Coupling is limited to on shore pipelines for
non-hazardous service and limited to 12 inch maximum diameter.
13.2.2 LokRing Coupling
The use of LokRing coupling is limited to piping 2 inch maximum for
instrument air, nitrogen gas, and water service.
13.3 Clamp-type connectors for high pressure services shall conform to API SPEC
6A or shall be proprietary connectors of a design based on ASME SEC VIII and
approved by the Chairman, Piping Standards Committee in the Consulting
Services Department (for example, Grayloc, Techlok, etc.).
13.4 Proprietary couplings for pipeline repair, such as Plidco, Weld + Ends
couplings, proprietary swivel joints, such as Chiksan, or similar specialties shall
be of a design approved by the Chairman, Piping Standards Committee in the
Consulting Services Department.
Revision Summary
30 September 2003 This new revision consolidates the original SAES-L-007 and SAES-L-010 plus additional
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
sections from SAES-L-005. Also, major changes were introduced.
30 March 2005 Editorial revision to replace NACE MR0175 with newly approved SAES-A-301.
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Document Responsibility: Piping SAES-L-110
Issue Date: 30 March 2005
Next Planned Update: 1 October 2008 Limitations on Pipe Joints and Components
Chart 1 – Branch Connections
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