1、MSS SP-83-2014 Class 3000 and 6000 Pipe Unions, Socket Welding and Threaded (Carbon Steel, Alloy Steel, Stainless Steels, and Nickel Alloys)Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, Virgi
2、nia 22180-4602 Phone: (703) 281-6613 Fax: (703) 281-6671 E-mail: standardsmss-hq.org www.mss-hq.org MSS STANDARD PRACTICE SP-83i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 105 and the MSS Coordinating Committee. The content of this Standard Practice i
3、s the resulting efforts of competent and experienced volunteers to provide an effective, clear, and non-exclusive standard that will benefit the industry as a whole. This MSS Standard Practice describes minimal requirements and is intended as a basis for common practice by the manufacturer, the user
4、, and the general public. The existence of an MSS Standard Practice does not in itself preclude the manufacture, sale, or use of products not conforming to the Standard Practice. Mandatory conformance to this Standard Practice is established only by reference in other documents such as a code, speci
5、fication, sales contract, or public law, as applicable. MSS has no power, nor does it undertake, to enforce or certify compliance with this document. Any certification or other statement of compliance with the requirements of this Standard Practice shall not be attributable to MSS and is solely the
6、responsibility of the certifier or maker of the statement. “Unless indicated otherwise within this MSS Standard Practice, other standards documents referred to herein are identified by the date of issue that was applicable to this Standard Practice at the date of approval of this MSS Standard Practi
7、ce (see Annex A). This Standard Practice shall remain silent on the validity of those other standards of prior or subsequent dates of issue even though applicable provisions may not have changed.” By publication of this Standard Practice, no position is taken with respect to the validity of any pote
8、ntial claims(s) or of any patent rights in connection therewith. MSS shall not be held responsible for identifying any patent rights. Users are expressly advised that determination of patent rights and the risk of infringement of such rights are entirely their responsibility. In this Standard Practi
9、ce all text, notes, annexes, tables, figures, and references are construed to be essential to the understanding of the message of the standard, and are considered normative unless indicated as “supplemental“. All appendices, if included, that appear in this document are construed as “supplemental“.
10、Note that “supplemental” information does not include mandatory requirements. This Standard Practice has been substantially revised from the previous 2006 edition. It is suggested that if the user is interested in knowing what changes have been made, that direct page by page comparison should be mad
11、e of this document and that of the previous edition. Non-toleranced dimensions in this Standard Practice are nominal unless otherwise specified. Any excerpts of this Standard Practice may be quoted with permission. Credit lines should read Extracted from MSS SP-83-2014 with permission of the publish
12、er, Manufacturers Standardization Society of the Valves and Fittings Industry. Reproduction and/or electronic transmission or dissemination is prohibited under copyright convention unless written permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry In
13、c. All rights reserved. Originally Approved/Published: September 1976 Current Edition Approved October 2014 Current Edition Published December 2014 MSS is a trademark of the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Copyright 2014 by Manufacturers Standardization
14、 Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-83ii FOREWORD This Standard Practice was originally approved in 1976; providing coverage for Class 3000 Carbon Steel Unions primarily for use in high-pressure industrial, oil-field, and petrochemical industr
15、ies. In 1987, austenitic stainless steel grades 304/304L and 316/316L were added for use in process chemical, pharmaceutical, power generation, and other industries where corrosion resistance was a major concern. In 1995, socket-welding union dimensions for socket diameters, socket wall thicknesses,
16、 and union “water-way” bores were aligned to correspond with dimensions of the ASME B16.11 Class 3000 fittings specification. In the 2001 edition, the waterways of threaded unions were adapted to allow the use of the larger diameters of the drills used for NPT threading, which is in line with practi
17、ces for threaded fittings use within the same piping systems. In 2006, the Standard Practice was essentially reaffirmed with minor editorial changes. The 2014 revision represents a substantive revision for SP-83. The committee reviewed and confirmed the basis for the original pressure-temperature ra
18、tings contained in the Standard Practice and pressure-temperature tables were updated as a result. Based on formula, test, and field experience, coverage for numerous alloy steel, stainless steel and nickel alloy grades were added to the Standard Practice. In addition, on the same basis, dimensions,
19、 materials, and pressure-temperature ratings were added for the new inclusion of Class 6000 socket-welding and threaded unions. The revisions contained in this edition provide for a more robust and comprehensive standard for pipe unions, intended for commercial and industrial applications of a wide
20、variety. CAUTIONARY NOTES REGARDING INSTALLATION OF PIPE UNIONS a) Leakage from a union can result when joining pipe ends which are poorly aligned. b) Care should be taken to avoid placing unions in lines subject to live loads and bending loads, which may cause leakage. c) Care should be taken to pr
21、event damage to the seating surfaces. d) Due consideration should be given to the possibility of shock pressure in the system. e) Installation techniques or instructions are outside the scope of this Standard Practice. NOTE: Union parts from different manufacturers are not functionally interchangeab
22、le and combining parts from different manufacturers is not recommended. MSS STANDARD PRACTICE SP-83iii TABLE OF CONTENTS SECTION PAGE 1 SCOPE 1 2 PRESSURE RATINGS . 1 3 SIZE 1 4 DESCRIPTION . 1 5 MARKING . 1 6 MATERIAL 2 7 TESTS . 2 8 DESIGN AND DIMENSIONS . 2 9 SOCKET WELDING UNIONS . 2 10 THREADED
23、 UNIONS . 3 11 NUT THREADS . 3 12 FINISH 3 13 TOLERANCES . 3 14 CORROSION PROTECTION 3 TABLE 1 Correlation of Class Designation with Pipe Schedule 1 2 Nominal Wall Thickness of Schedule 160 Pipe 1 3 Terminology of Parts 1 4 Pressure-Temperature Service Rating, Class 3000 Pipe Unions Socket Welding a
24、nd Threaded Ends . 4 5 Pressure-Temperature Service Rating, Class 6000 Pipe Unions Socket Welding and Threaded Ends . 5 6 Minimum Recommended Nut Tightening Torque for Checking Coincidence of Axis 6 7 Class 3000 Pipe Unions Socket Welding Ends 7 8 Class 6000 Pipe Unions Socket Welding Ends 8 9 Class
25、 3000 Pipe Unions Threaded Ends 9 10 Class 6000 Pipe Unions Threaded Ends 10 FIGURE 1 Welding Gap . 2 2 Recommended Method for Checking Coincidence of Axis on Threaded Unions 6 ANNEX A Referenced Standards and Applicable Dates . 11 MSS STANDARD PRACTICE SP-831 1. SCOPE1.1 This Standard Practice esta
26、blishes envelope and other essential dimensions, finish, tolerances, testing, marking, material, and minimum performance requirements for forged carbon steel, alloy steel, stainless steel, and nickel alloy pipe unions, socket welding and threaded ends. 2. PRESSURE RATINGS2.1 These unions shall be de
27、signated as Class 3000 or Class 6000, socket welding or threaded and shall carry ratings shown in Table 4 for Class 3000 or Table 5 for Class 6000. 2.2 Class designations of these unions are correlated with ASME B36.10 Pipe Schedule Thicknesses as shown in Table 1. TABLE 1 Correlation of Class Desig
28、nation with Pipe Schedule Class Designation of Union Pipe Used in Wall Thickness Calculations (a)3000 Schedule 80 6000 Schedule 160 NOTE: (a) This table is not intended to restrict the use of pipe of thinner or thicker wall with unions. The pipe actually used may be thinner or thicker in nominal wal
29、l than that shown in this table. The rating of the pipe, or the rating of the union as shown in Tables 4 or 5, whichever is less, may govern the rating of the system. 2.3 Since ASME B36.10 does not include Schedule 160 thickness for NPS 1/8, 1/4 and 3/8, the values in Table 2 shall be used as the no
30、minal wall thicknesses of the pipe. TABLE 2 Nominal Wall Thickness of Schedule 160 Pipe NPS of Union Schedule 160 Nominal Wall 1/8 0.124 1/4 0.145 3/8 0.158 3. SIZE3.1 The size of the union is identified by the nominal pipe size (NPS). 4. DESCRIPTION4.1 The complete union shall consist of three part
31、s: male end, female end, and, nut. Equivalent terms are tabulated in Table 3. TABLE 3 Terminology of Parts Preferred Term Equivalent Terms Male Male seatend Tail Piece Nut Piece Coupling Ball End Female Female seatend Thread Piece Body Head Cone End Nut Union Coupling Nut Swivel Ring 4.2 The seating
32、 surfaces of the joint shall be integral metal-to-metal, ball-to-cone design. Male and Female ends shall be machined with sockets for socket welding or threaded with internal NPT pipe threads. Male and Female ends and Nuts may be round, polygon, or modified polygon with rounded corners, at the optio
33、n of the manufacturer. The length of the union ends shall be sufficient to provide a suitable wrenching surface. 5. MARKING5.1 Each union part shall be permanently marked in accordance with MSS SP-25. The marking shall include (but is not limited to) the following: a) Manufacturers name or trademark
34、.b) Material grade identification - in accordancewith the requirements of the applicableASTM specifications listed in Tables 4 or 5.Note: Multiple material markings shall be allowed as covered in ASTM material specifications listed in Tables 4 or 5. c) Material lot or heat number for traceability.d)
35、 Service designation: 3000 or 3M or 6000 or6M (M to designate units of 1000).e) The nominal pipe size.CLASS 3000 AND 6000 PIPE UNIONS, SOCKET WELDING AND THREADED (CARBON STEEL, ALLOY STEEL, STAINLESS STEELS, AND NICKEL ALLOYS) MSS STANDARD PRACTICE SP-832 5.2 All three parts of a union, in complian
36、ce with all requirements of this SP, shall be marked “SP83”. 5.3 Unions manufactured from materials meeting all the ASTM material specification requirements for more than one specification, class or grade, may, at the manufacturers option, be marked with more than one specification, class or grade d
37、esignation, such as F304/304L and F316/316L, or A105/A234 WPB. 6. MATERIAL 6.1 Unions shall conform to the requirements of the material specifications, grades and classes listed in Tables 4 and 5. 6.2 The three parts of a union assembly shall be manufactured from materials which have the same requir
38、ements for chemical composition, mechanical properties, and applicable heat treatment. 6.3 Union parts may be forged, seamlessly formed, or made from wrought bars conforming to the requirements for the grades and classes of the ASTM material specifications listed in Tables 4 and 5. 6.4 Unions may be
39、 made from other wrought seamless materials by agreement between the manufacturer and the purchaser, but shall not be marked “SP83”. 7. TESTS 7.1 Pressure testing is not required by this standard. 8. DESIGN AND DIMENSIONS 8.1 Socket Wall Thickness for Socket Welding Unions The socket wall thickness
40、shall be no less than the corresponding values, C, shown in Tables 7 and 8. 8.2 Minimum Body Wall Thickness for Socket Welding Unions The minimum body wall thickness, other than socket wall, must be equal to or greater than the nominal wall thickness of Schedule 80 pipe for Class 3000 or Schedule 16
41、0 pipe for Class 6000 of the same size as the union, as established by ASME B36.10M. 8.3 Minimum Wall Thickness for Threaded Unions (See Dimension C in Table 9 for Class 3000 and Table 10 for Class 6000) The minimum wall thickness at the root of the pipe thread at the wrench tight plane must equal o
42、r exceed the nominal wall thickness for Schedule 80 pipe for Class 3000 or Schedule 160 pipe for Class 6000. 8.4 Other Dimensions The dimensions for unions capable of meeting this standard are shown in Tables 7 and 8 for socket welding unions and Tables 9 and 10 for threaded unions. 8.5 Union parts
43、from different manufacturers are not functionally interchangeable and combining parts from different manufacturers is not recommended. 9. SOCKET WELDING UNIONS 9.1 To provide assembled union uniformity this Standard Practice establishes dimensions (Table 4, Column E) for the location of the bottom o
44、f the sockets. Socket welding union ends shall be faced at right angles to the axis to provide a flat surface against which to weld and the socket shall be counter-bored or otherwise machined to insure uniform depth and circularity. 9.2 When installing socket weld end unions, to minimize the possibi
45、lity of cracking of the fillet welds, it is recommended that the connecting pipe be withdrawn approximately 0.06 inches away from the bottom of the union socket bore before welding (see Figure 1). Figure 1 Welding Gap MSS STANDARD PRACTICE SP-833 10. THREADED UNIONS 10.1 Dimensions for threaded unio
46、ns are shown in Tables 9 and 10. Internal pipe threads shall be NPT in accordance with ASME B1.20.1. Gaging procedures and practice shall be in accordance with Section 3.1 of the same ASME standard. 11. NUT THREADS 11.1 Internal threads of the nut and external threads of the (Threadpiece) Female par
47、t shall be American National Thread form made in accordance with the formulae for special threads appearing in ASME B1.1, Unified and American Screw Threads, Class 2A External and 2B Internal Tolerances and Clearances. 11.2 At manufacturers option, changes to the values in Column “H” are permitted,
48、provided the requirements of ASME B1.1 and all requirements of this Standard Practice are met. 12. FINISH 12.1 Surfaces must be free of sharp burrs and have a workmanlike finish. 13. TOLERANCES 13.1 General Tolerances are listed in Tables 7, 8, 9, and 10. 13.2 Concentricity The socket shall be conce
49、ntric with the waterway bore within a tolerance of plus or minus 0.03 (0.03) inches for all sizes. 13.3 Coincidence of Axis The maximum allowable variation in the alignment of one threaded pipe end of the assembled union to the axis of the opposite threaded pipe end shall not exceed 0.19 inches in 1 foot. Figure 2 illustrates one method that may be used to check alignment. Recommended minimum nut tightening torque values for checking coincidence of axis are listed in Table 6. 14. CORROSION PROTECTION 14.1 Carbon and alloy steel unions
