Previous Issue: 28 January 2004 Next Planned Update: 1 November 2010
Revised paragraphs are indicated in the right margin Page 1 of 17
5 October 2005
Hot Tap and Stopple Fittings
Materials and Corrosion Control Standards Committee Members
Al-Anezi, Mohammed A., Chairman Al-Rumaih, Abdullah M., Vice Chairman Abdulhadi, Abdullatif I. Al-Anizi, Salamah S. Al-Gahtani, Moraya S. Al-Ghasham, Tawfiq Y. Al-Mugbel, Wajdi M. Al-Nabulsi, Khalid M. Al-Sannaa, Muhsen S. Balhareth, Nasser M. Bash, Fahad M. Burgess, Brian W. Choi, Ho J. Cruz, Ivan C. Dias, Olavo C. Kermad, Abdelhak Lobley, Graham R. Mehdi, Mauyed S. Moore, Mark A. Niemeyer, D.C. Palmer, Robert E. Stark, Gregory D. Tems, Robin D.
Saudi Aramco DeskTop StandardsTable of Contents
1 Scope... 3
2 Conflicts and Deviations... 3
3 References... 3
4 Purchase Order Information ... 5
5 General... 5 6 Design... 6 7 Materials... 8 8 Fabrication... 11 9 Tolerances... 13 10 Repair of Defects... 14
11 Inspection and Testing... 14
12 Marking... 16
13 Preparation for Shipment... 17
14 Material Selection and Testing Subcommittee... 17
This specification provides the requirements for design, material selection, fabrication, testing and marking of hot tap and stopple fittings including: split tees, stopple fittings, full encirclement saddles, flanges and Lock-O-Ring (LOR) flanges to be used in sweet or wet sour service. Additional requirements for sour service are given in paragraph 7.8. This entire specification may be attached to and made a part of purchase orders.
2 Conflicts and Deviations
2.1 Any conflicts between this specification and other applicable Saudi Aramco Materials System Specifications (SAMSSs), Engineering Standards (SAESs), Standard Drawings (SASDs), or industry standards, codes, and forms shall be resolved in writing by the Company through the Manager, Consulting Services Department of Saudi Aramco, Dhahran.
2.2 Direct all requests to deviate from this specification in writing to the Company who shall follow internal company procedure SAEP-302 and forward such requests to the Manager, Consulting Services Department of Saudi Aramco, Dhahran.
The selection of material and equipment, and the design, construction, maintenance, and repair of equipment and facilities covered by this specification 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 Standard
SAES-A-301 Materials Resistant to Sulfide Stress Corrosion Cracking
Saudi Aramco Inspection Requirements
Form 175-026400 Hot Tap and Stopple Fittings Saudi Aramco Standard Drawing
3.2 Industry Codes and Standards American Petroleum Institute
API SPEC 5L Specification for Line Pipe American Society of Mechanical Engineers
ASME B16.5 Steel Pipe Flanges and Flanged Fittings ASME B16.47 Large Diameter Flanges
ASME B31.3 Process Piping
ASME B31.4 Liquid Petroleum Transportation Piping Systems ASME B31.8 Gas Transmission and Distribution Piping
Systems ASME SEC II Materials
ASME SEC VIII Rules for Construction of Pressure Vessels ASME SEC IX Welding and Brazing Qualification
American Society for Testing and Materials
ASTM A105 Specification for Forgings, Carbon Steel for Piping Components
ASTM A106 Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service
ASTM A216 Specification for Steel Castings
ASTM A234 Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service ASTM A370 Standard Test Methods and Definitions for
Mechanical Testing of Steel Products
ASTM A516 Specification for Pressure Vessel Plates, Carbon Steel
ASTM A537 Specification for Pressure Vessel Plates, Heat-Treated Carbon-Manganese-Silicon Steel ASTM A578 Standard Specification for Straight-Beam
Ultrasonic Examination of Plain and Clad Steel Plates for Special Applications ASTM A694 Specification for Forgings, Carbon Steel and
ASTM A833 Standard Practice for Indentation Hardness of Metallic Materials by Comparison Hardness Testers
ASTM E10 Standard Test Method for Brinell Hardness of Metallic Materials
ASTM E92 Standard Test Method for Vickers Hardness ASTM E165 Standard Test Method for Liquid Penetrant
Examination Manufacturers Standardization Society
MSS SP-44 Steel Pipeline Flanges
MSS SP-75 Specification for High Test Wrought Butt-Welding Fittings
American Welding Society
AWS A5.XX Specifications for Welding Filler Metals (Series of Specifications)
4 Purchase Order Information
The Purchase Order shall specify the following:
a) Nominal size, thickness, and the material grade of the pipe to be tapped b) Nominal size of the branch
c) Overall length of the fitting (when limited by space)
d) Distance from center of run to end of outlet (when limited by space)
e) Design pressure, design temperature, design factor, test pressure and flange rating f) Applicable Code for split tees (see paragraphs 188.8.131.52 and 11.4.1)
f) Lock-O-Ring flange and plug, if required
g) Service fluid and condition (i.e., sour or non-sour)
Items specified or referenced by brand names or proprietary names are not intended to exclude equivalent items offered by other names. Products of comparable type, quality and characteristics may be submitted by the vendor with the Quotation for approval by CSD.
6.1 Split Tees
6.1.1 The split tee shall be provided with a 12.7 mm welding outlet, Class 3000 for field hydrostatic testing. This welding boss shall be located as indicated in Standard Drawing AB-036719.
6.1.2 If the branch size is fifty percent (50%) or more of the run size, then the calculated wall thickness, including reinforcement, of the split tee run shall be provided in the entire cross section of the two halves of the run (except for the recess for the backing strip)
6.1.3 The top half of the split tee shall have a 45-degree bevel on the longitudinal seams. The bottom half shall not be beveled. The circumferential weld ends shall be square beveled up to 0.75 inch. Thereafter, a 45-degree bevel shall be provided.
Refer to paragraph 9.1 for the maximum gap between the two halves and between pipe outside diameter and split tee inside diameter to clear the pipe weld reinforcement.
6.1.4 Backing strips for the field longitudinal welds shall be supplied. They shall be weldable carbon steel strips 1.6 mm thick and approximately 25 mm wide for sizes above 4" NPS or 12 mm wide for sizes 4" NPS and smaller. The length shall be the same as the length of the run of the split tee. A matching recess shall be machined into each half of the split tee. The backing strips shall be tack or skip welded to the top half of the split tee.
6.1.5 Flanges used for hot tap or stopple fittings shall meet the requirements of the bolting and seating area of ASME B16.5, ASME B16.47, MSS SP-44 or Standard Drawings specified in the Purchase Order.
6.1.6 Extruded Split Tees
184.108.40.206 The wall thickness of split tees of the extruded type shall be designed in accordance with the requirements of either ASME B31.4/ASME B31.8, paragraph 404.3.1(b)/831.4 or ASME B31.3, paragraph 304.3.3. In case ASME B31.4/ASME B31.8 is specified, the design factor shall be 0.5 (instead of 0.72) for SAMS stock procurement.
220.127.116.11 The minimum specified nominal thickness of extruded split tee runs (headers) shall be per Table 1:
Table 1 – Minimum Specified Nominal Thickness of Run (Header) for Extruded Tees
Split Tee Run Size Minimum Nominal Thickness of Split Tee Run
100-200 mm (4"-8") 9.5 mm (3/8") 250-350 mm (10"-14") 12.7 mm (1/2") 400-450 mm (16"-18") 19.1 mm (3/4") 510-560 mm (20"-22") 22.2 mm (7/8") 610 (24") and above 31.8 mm (1.25")
18.104.22.168 The maximum radius of curvature (rx) of the external
contoured portion of the outlet for extruded split tees (see Figure 1) used for stoppling operations shall not exceed: a) for outlet O.D. < 20" NPS, rx = 25.4 mm
b) for outlet O.D. ≥ 20" NPS,
rx = 7% of outlet O.D. + 12.7 mm.
6.1.7 Fabricated Split Tees
22.214.171.124 Split tees larger than 30 inch size intended for stoppling operations shall be of the fabricated type unless specifically approved by CSD.
126.96.36.199 For other applications and sizes, split tees with the branch welded to the run (instead of extruded) are acceptable, provided that the split tee can withstand the specified
hydrostatic test pressure without permanent deformation. The wall thickness of split tees with a welded branch shall be designed to provide integral reinforcement of the branch opening as required by either ASME B31.4/ASME B31.8,
paragraph 404.3.1(b)/831.4 or ASME B31.3, paragraph 304.3, as applicable.
188.8.131.52 The minimum specified nominal thickness of the run (header) for all sizes of fabricated tees shall be 19.1 mm (0.75"). 6.2 Full Encirclement Saddles
6.2.1 Full encirclement saddles shall be in accordance with Standard Drawing
AB-036719 Type 1.
The branch shall be extruded or forged to the run. Saddles which have the outlet welded to the run are prohibited. Only longitudinal seams are permitted. The dimensions and plate thickness shall be as indicated in the Purchase Order.
6.2.2 Side straps shall be provided and welded to the bottom half of the saddle with continuous full size fillet welds. The side straps shall be 50 mm wide if the run is under 600 mm. For runs 600 mm and larger the side straps shall be 75 mm wide. The thickness of the straps shall be equal to the thickness of the run.
6.2.3 The outlet shall have an outside knuckle radius of 25 mm minimum. 6.2.4 The top half of the run shall be provided with a vent hole 3 mm in
6.3 Lifting lugs shall be provided on both sides of the lower half of all fittings size 10 in and larger.
7.1.1 The material shall be equivalent to one of the specifications listed below. The mechanical and chemical properties of the split tee material shall be similar to the pipe material where it will be installed, as specified in the Purchase Order. Split tee materials of lower yield strength than the pipe may be used unless this would result in a nominal wall thickness in excess of 38 mm.
7.1.2 Boron shall not be intentionally added, and the residual level shall not exceed 0.0005%.
7.2.1 Materials shall conform to the requirements of ASTM A234/ASTM A234M Grade WPB including Supplementary Requirements S1 "Product Analysis".
7.2.2 High strength starting stock shall not be used for Grade WPB fittings without prior approval by CSD. In no case shall the actual yield strength of the finished fittings exceed 386 MPa (56,000 psi) unless approved by CSD. All other requirements shall conform to ASTM A234 WPB. 7.2.3 The carbon equivalent (CE) shall not exceed 0.42% when calculated
according to the formula:
15 ) ( 5 ) ( 6 ) (IIW C Mn Cr Mo V Ni Cu CE = + + + + + + (1)
7.3 Grade X42 Through X70 Fittings
7.3.1 With the exception of the chemical composition requirements in paragraph 7.3.2 and impact testing requirements in paragraph 7.3.3 below, the material shall conform to the requirements of MSS SP-75, with Supplementary Requirements SR-4 for hardness only., SR-5 (actual yield strength limitation).
7.3.2 Chemical composition, including carbon equivalent, shall be in accordance with the following table:
Table 2 – Chemical Composition
Requirement of Grade X42 through X70 Fittings
Chemical Requirements Composition Weight % Product Analysis Carbon 0.20 Manganese 1.00–1.45 Phosphorus 0.030 Sulfur 0.010 Silicon 0.15–0.40 c Nickel 0.50 d Chromium 0.30 d Molybdenum 0.25 d Copper 0.35 d Titanium 0.05 Vanadium 0.10 Columbium 0.04
Vanadium plus Columbium 0.12
a) All values are maximum unless a range is stated
b) The carbon equivalent, as calculated by the formula in 7.2.3, shall not exceed 0.42 %
c) If vacuum carbon deoxidation is used, silicon shall not exceed 0.10 % by heat analysis and 0.12 % by product analysis. d) The sum of Ni + Cr + Mo + Cu shall not exceed 1.0%.
7.3.3 Charpy impact notch toughness testing
a) Impact testing is required for all sizes (including less than 14") and grades (i.e., X42 through X70).
b) The impact tests shall be conducted at -18°C (0°F) in accordance with ASTM A370.
c) Welding procedure qualifications shall include impacts tests of the base metal, weld metal, and heat-affected zone (HAZ).
d) The average of three specimens shall not be less than 25 ft-lbs (35 J). The lowest single value shall not be less than 20 ft-lbs (28 J).
7.4 The vendor shall provide a certified material test report listing the actual results of the chemical analysis, mechanical properties, notch toughness properties, heat treatment, non-destructive examination, and any special tests required by the Purchased Order.
7.5 Starting stock materials used to manufacture fittings shall conform to one of the following materials. Materials conforming to other national standards may be used, subject to approval by CSD.
a) Welded fittings: ASTM A516 (all grades) or ASTM A537 (all grades) b) Seamless fittings: ASTM A106 or API SPEC 5L (seamless only) c) Material for LOR plugs shall be per ASTM A694, ASTM A105M or
If the Purchase Order specifies a grade with higher SMYS (specified minimum yield strength) than the materials listed above, then the vendor shall submit their proposed materials to CSD for approval.
7.6 All other non-pressure containing components shall be vendor's standard material.
7.7 All O-rings supplied for use on LOR plugs shall be the molded type. O-rings with joints (including those made by joining O-ring cord) are not acceptable. 7.8 For Sour service the following additional requirements are applicable:
7.8.1 The steel shall be vacuum degassed.
7.8.2 The maximum sulfur shall be 0.002%. Sulfur content up to and including 0.005% is acceptable if the steel is calcium treated for inclusion shape control. Typical calcium content is between one and three times the sulfur content.
7.8.3 The maximum phosphorous shall be 0.015%.
7.8.4 The fitting shall be 100% UT examined for laminations in accordance with ASTM A578. The acceptance level is C. The edges of the fitting shall be free of laminations for a width of 50 mm.
8.1.1 All Welding Procedure Specifications and Procedure Qualification Records shall be written in English and conform to ASME SEC IX. 8.1.2 All welders shall be qualified in accordance with ASME SEC IX,
including tack welders. 8.1.3 Processes
The following processes are approved for use: 184.108.40.206 Shielded Metal Arc Welding (SMAW) 220.127.116.11 Gas Tungsten Arc Welding (GTAW) 18.104.22.168 Submerged Arc Welding (SAW)
22.214.171.124 Gas Metal Arc Welding (GMAW) - Short Circuiting transfer shall not be used.
126.96.36.199 Flux Cored Arc Welding (FCAW) - Shall not be used for the root pass on single sided welds.
8.1.4 Welding without the addition of filler material is not permitted. 8.1.5 Welding Consumables
188.8.131.52 Electrodes, filler wires, and fluxes shall conform to the requirements of the ASME SEC II, Part C (identical to the AWS A5.XX specification series). Other consumables may be used only with the specific approval by CSD.
184.108.40.206 Low-hydrogen processes shall be used for all fittings when the wall thickness exceeds 13 mm.
220.127.116.11 A change in filler metal deposit chemistry from A-No. 1 of ASME SEC IX to A-No. 2 and vice-versa is not permitted without requalification.
18.104.22.168 Active Submerged Arc Welding fluxes shall not be used. 8.1.6 Welding Procedure Qualifications
Any GMAW electrode to be used for procedures with impact toughness requirements and any SAW flux or FCAW electrode shall be restricted to the specific brand, type, and maximum size as used for the PQR. If so restricted, the brand name and type of flux or electrode shall be specified on both the WPS and PQR.
22.214.171.124 Hardness Testing
Hardness testing conducted in accordance with ASTM E92, shall be made on a full-thickness, transverse cross-section of the weld that has been mounted, polished to metallographic quality, and etched. Two traverses shall be made, one within 1.0 mm from the O.D. surface and one within 1.0 mm from the I.D. surface. Each traverse shall consist of at least two
hardness indentations in each of the following locations: • Parent metal on left-hand side of the weld,
• heat affected zone as close as possible to the fusion line on the left-hand side of the weld,
• weld metal,
• heat affected zone as close as possible to the fusion line on the right-hand side of the weld, and
• parent metal on right-hand side of the weld.
Only Vickers 5 kg or 10 kg hardness testers shall be used. Hardness of base metal, HAZ, and weld metal shall not exceed VHN 250.
8.2 Extruded Split Tees and Full Encirclement Saddles
Extruded split tees and full encirclement saddles shall have the outlet hot extruded.
8.3 Split Tees with the Branch Welded
Split tees with the branch welded to the run shall have full penetration welds as indicated in ASME B31.4, Figure 404.3.1(c)(3) or ASME B31.8, Appendix I Figure I1.
8.4 Heat Treatment
8.4.1 All fittings shall be heat treated after all forming and welding processes are completed. Flanges may be welded to the heat treated tee without re-heat treating provided that the re-heat treatment of the flange to tee weld is not required by the governing code.
8.4.2 All fittings supplied in accordance with this specification shall be heat treated as follows:
Table 3 – Heat Treatment of Extruded Tee and Branch Welds
Extruded Tee or Branch Weld Heat Treatment
Extruded Tee Normalize, Normalize and temper, or
quench and temper
Welded Tee Post-weld Heat Treatment (PWHT)
Flange to Tee PWHT if required by governing code or
Stress relieved, or normalized, or normalized and tempered, or quenched and tempered shall be as defined in ASTM A234 or MSS SP-75.
8.4.3 Seamless Grade WPB fittings for which the final forming operation is completed at a temperature above 620°C and below 980°C need not be subsequently heat treated provided they are cooled in still air.
8.4.4 Hot formed high strength fittings shall be cooled below the lower critical temperature prior to heat treatment.
9.1 Fittings shall have tolerances such that they provide the following gaps between the inside radius of fitting (sleeve) and the nominal outside radius of pipe:
660 mm and larger: 6.4 mm max.
9.2 The fittings dimensions shall provide a root gap on the longitudinal joint of 3.2 to 8.0 mm when fit onto the specified nominal size pipe.
9.3 Inside diameter of outlet : ± 1.6, -0 mm of specified nominal ID (measured by gage or caliper of actual diameter in all directions)
9.4 Wall thickness of fitting : ± 12.5% of specified thickness 9.5 Center run to top outlet : ± 3.2 mm of specified distance 9.6 Length of fitting : ± 9.5 mm of specified length 9.7 Intersection of centerline of
branch with centerline of run : 1.6 mm max. offset
9.8 The flange face shall be parallel within 0.8 mm with a plane perpendicular to the centerline of the branch, as measured from the edge of the flange.
10 Repair of Defects
10.1 Repair of any imperfection in finish shall be in accordance with ASTM A234, Section 12.
10.2 Cracks shall be repaired only if approved by Inspection. The vendor shall submit details of the repair procedure and nondestructive examination of the repair area for Inspection's approval for any crack repairs prior to making the repair.
10.3 Unsuccessful weld repairs after the second attempt shall be completely cut out and replaced.
11 Inspection and Testing
The fittings are subject to inspection by Saudi Aramco Inspection representative per Saudi Aramco Inspection Requirements Form 175-026400 attached to the Purchase Order.
11.2 Visual Examination and Dimensional Check
General appearance shall show good workmanship and fit-up. Weld surfaces shall show a smooth contour. Welds shall be visually inspected in accordance
with ASME B31.3 Normal Fluid Service. Dimensions of the fitting shall be checked against approved vendor's drawings.
11.3 Non-destructive Examination
11.3.1 The plate to be used for the fabrication of high yield strength fittings which have a specified minimum yield strength of 359 MPa (52 000 psi) and higher shall be ultrasonically tested for laminations in accordance with ASTM A578 (acceptance level C). The edges of the fitting shall be free of laminations for a width of 50 mm.
11.3.2 All butt welds in fabricated fittings, regardless of strength level, shall be 100% radiographed in accordance with ASME SEC VIII Div. 1, UW-51.
11.3.3 All other full penetration groove welds shall be inspected by magnetic particle testing (MT) in accordance with ASME SEC VIII Div. 1, Appendix 8.
11.3.4 All weld ends (longitudinal and circumferential) for field welding shall be checked with dye penetrant (color contrast penetrant) in accordance with ASTM E165. Acceptance criteria shall be per ASME SEC VIII Div. 1, Appendix 8.
Alternatively, the weld ends may be magnetic particle tested in accordance with ASME SEC VIII Div.1, Appendix 8.
11.4 Pressure Tests
11.4.1 Fabricated fittings shall be hydrostatic tested if the branch size is in the range from two sizes smaller than the run (header) up to the same size as the run (header). The test pressure shall be 1.5 times its MAOP for fittings designed to ASME B31.3 Code. For fittings designed to ASME B31.4/ASME B31.8 Code, the test pressure shall be 1.25 times its MAOP for design factor of 0.72, and 1.5 times its MAOP for design factors of 0.5 and 0.6.
11.4.2 The Lock-O-Ring plug shall be hydrostatic tested to 1.25 times the MAOP from the underside (header side) of the plug. No leakage of the O-ring seals is allowed.
11.5 Production Hardness Tests
The hardness tests shall be conducted on all fittings:
11.5.2 A minimum of three hardness indentations shall be made on the parent metal of each fitting, with the test locations spaced evenly across the piece being tested. For extruded fittings one of the hardness shall be in the outlet section. For fabricated fittings, an additional three hardness indentations shall be made, evenly spaced, along the weld. Where accessible, the weld metal hardness should be measured on the I.D. surface of the fittings.
11.5.3 The hardness shall not exceed 236 HB. If any single indentation exceeds the allowable hardness limit, two additional hardness
indentations shall be taken within 25 mm of the first reading, and the three hardness values shall be averaged. If the average exceeds the allowable limit, the fitting shall be rejected, and all the other fittings from the same heat shall be 100% hardness tested.
11.5.4 At the manufacturer's option, all fittings that have failed the hardness test requirements in paragraphs 11.5.3 may be re-heat treated and hardness tested again. The second heat treatment shall be equivalent to the original heat treatment unless additional production test coupons are made to verify all the required mechanical properties are met. Any second heat treatment must still comply with the original welding procedure essential and supplementary essential variables. Fittings that pass the hardness test requirements and the strength requirements after re-heat treatment may be accepted. Fittings that fail a second time shall be permanently rejected.
11.6 Production Tensile Test
A tensile test shall be performed on one specimen per lot of extruded fitting production and shall meet the requirements of the basic specification.
12.1 The fittings shall be marked with a 100 mm wide painted band around top and bottom half at one end in order to facilitate matching during field installation. 12.2 Top and bottom halves shall be stencil-marked with Saudi Aramco Purchase
Order number, item number, nominal size, type of material, maximum allowable operating pressure, hydrotest pressure, fitting weight, and actual Carbon
Equivalent of the header material. The stenciled marking shall be made on the inside and outside of the fitting run. For LOR plugs, the Purchase Order number and the item number shall be stenciled on the top (outer) surface.
The top and bottom halves shall also be die-stamped, using low stress stamps, with the Purchase Order and item number. The stamping shall be adjacent to the stencil-marks.
12.3 Fittings purchased for non-sour service shall be identified by painting a white longitudinal stripe for the full length of the fitting. The stripe shall be 50 mm on the outside surface of both halves. Fittings purchased for sour service shall be stenciled "for sour service."
12.4 Hot tap and stopple fittings shall have the maximum allowable operating
pressure and temperature die-stamped on the flange rim. The die stamping shall be made on the bottom run as well as the flange run of the fitting.
13 Preparation for Shipment
Export packing, marking and shipping shall be in accordance with the Purchase Order.
14 Material Selection and Testing Subcommittee Graham Lobley Coordinator
Abdullah Al-Rumaih Member
Fahad Al-Bash Member
Olavo Dias Member
Muhsen Al-Sannaa Member
Mauyed Mehdi Member
Nasser Balhareth Member
Khalid Al-Nabulsi Member
Robin Tems Member
Abdelhak Kermad Member
Brian Burgess Member
Hojin Choi Member
Gregory Stark Member
Wajdi Al-Mugbel Member