1、 MSS SP-87-1991 Reaffirmed 1996 Reinstated 2011 Factory-Made Butt-Welding Fittings for Class I Nuclear Piping Applications Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, Virginia 22180-4602 Ph
2、one: (703) 281-6613 Fax: (703) 281-6671 E-mail: infomss-hq.org www.mss-hq.org i MSS STANDARD PRACTICE SP-87 This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 113, and the MSS Coordinating Committee. The content of this Standard Practice is the result of the
3、efforts of competent and concerned volunteers to provide an effective, clear, and non-exclusive specification that will benefit the industry as a whole. This MSS Standard Practice is intended as a basis for common practice by the manufacturer, the user, and the general public. The existence of an MS
4、S Standard Practice does not in itself preclude the manufacture, sale, or use of products not conforming to the Standard Practice. Mandatory conformance is established only by reference in a code, specification, sales contract, or public law, as applicable. “Other standards documents referred to her
5、ein are identified by the date of issue that was applicable to this Standard Practice at the date of issue of this Standard Practice. See Annex A. This Standard Practice shall remain silent on the applicability of those other standards of prior or subsequent dates of issue even though applicable pro
6、visions may not have changed. References contained herein which are bibliographic in nature are noted as supplemental in the text.” By publication of this Standard Practice, no position is taken with respect to the validity of any potential claim(s) or of any patent rights in connection therewith. M
7、SS 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 Practice all notes, annexes, tables, and figures are construed to be ess
8、ential to the understanding of the message of the standard, and are considered part of the text unless noted as “supplemental“. All appendices appearing in this document are construed as “supplemental“. “Supplemental“ information does not include mandatory requirements. Non-toleranced dimensions in
9、the Standard Practice are nominal, and, unless otherwise specified, shall be considered “for reference only.“ Any part of this Standard Practice may be quoted. Credit lines should read Extracted from MSS SP-87-1991 (R 1996 Reinstated 2011) with permission of the publisher, the Manufacturers Standard
10、ization Society of the Valves and Fittings Industry, Inc. Reproduction is prohibited under copyright convention unless written permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry Inc. Originally Approved/Published: September 1977 Originally Withdrawn
11、: December 2001 Reinstated: March 2011 Copyright , 1982 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. NOTICE: MSS SP-87-1991 (R 1996) was reinstated in 2011 for the purpose of making an active version available to those utilizing the Standard Pra
12、ctice and/or complying with nuclear-related codes and piping applications. CONTENTS SECTION PAGE 0. INTRODUCTION 1 1. SCOPE . 1 2. REFERENCES . 1 3. WELDING . 1 4. PRESSURE RATINGS . 1 5. SIZE 3 6. MARKING 3 7. MATERIAL . 3 8. FITTING DIMENSIONS 3 9. SHAPE REQUIREMENTS 3 10. METHOD OF MANUFACTURE .
13、4 TABLE 1. TOLERANCES 5 2. DIMENSIONS OF LONG RADIUS ELBOWS . 6 3. DIMENSIONS OF SHORT RADIUS ELBOWS . 7 4. DIMENSIONS OF LONG RADIUS RETURNS . 7 5. DIMENSIONS OF SHORT RADIUS RETURNS . 8 6. DIMENSIONS OF STRAIGHT TEES . 8 7. DIMENSIONS OF REDUCING OUTLET TEES 9 8. DIMENSIONS OF CAPS . 11 9. DIMENSI
14、ONS OF REDUCERS . 12 ANNEX A. LIST OF REFERENCED STANDARDS 14 ii MSS STANDARD PRACTICE SP-87 FACTORY-MADE BUTT-WELDING FITTINGS FOR CLASS I NUCLEAR PIPING APPLICATIONS 0. INTRODUCTION Pipe Fittings for Nuclear Class I applications require dimensional and testing controls beyond those presently conta
15、ined in existing ANSI Standards to provide more stringent design adequacy requirements in keeping with the high reliability needed for Class I nuclear power plant piping systems. 1. SCOPE The objective of this Standard is to provide production type fittings which are suitable for application of the
16、stress indices and flexibility factors given in NB-3600 of the ASME Boiler and Pressure Vessel Code, Section III, Division 1, Nuclear Power Plant components. It is recog- nized that certain conditions will require fittings over and beyond the scope of this standard and in order not to complicate thi
17、s production fitting standard, such fitting must be negotiated be- tween purchaser and manufacturer. This standard covers overall dimensions, tolerances and marking for wrought carbon and alloy-steel (ferritic and austenitic) factory-made welding fittings including long and short radius, 90 degree e
18、lbows (not reducing), 45 degree long radius elbows, 180 degree long and short radius returns, straight and reducing tees, concentric reducers and caps. Both seamless, and welded fittings manufactured to the requirements of Section III Nuclear Power Plant Components are included. In case of conflict
19、between this standard and ANSI ASME B16.9 or ANSI/ASME B16.28, the requirements of this standard are applicable. 2. REFERENCES Standards and specifications adopted by refer- ence in this standard are shown in Annex A, for convenience of identifying edition number, date and source of supply. 3. WELDI
20、NG Only longitudinal and circumferential welds are permitted within a fitting. The characteristics shall be identified by the manufacturer as indi-cated in Table NB3682.a-1 of the ASME Boiler and Pressure Vessel Code, Section III, Division I, and properly certified and stamped. Unless otherwise spec
21、ified by the purchaser, non-flush or flush welds may be provided at the manufacturers option. This information shall be furnished upon request. 4. PRESSURE RATINGS Fittings shall be designed for the pressure ratings calculated for straight pipe having a joint efficiency of 1, of the same or equivale
22、nt material, with which they are recommended for use. The design adequacy of elbows, returns, concentric reducers, and caps are acceptable without proof test when calculated as described in Subsection 4.1, or at the manufacturers option, by proof testing in accordance with Subsection 4.2. The design
23、 of tees shall be estab- lished by proof test in accordance with Sub- section 4.2. 4.1 Calculated Design Adequacy 4.1.1 The design of long radius elbows and returns is considered acceptable provided the wall thickness in the inner arc is not less than the nominal thickness of the pipe, except at the
24、 ends where the wall thickness is not less than 87 percent of nominal. The design of short radius elbows and returns is considered acceptable provided the wall thickness in the inner arc is not less than 1.2 times the nominal thickness of the pipe, except at the ends where the wall thickness is not
25、less than 87 percent of nominal. 4.1.2 The design of concentric reducers, and caps is considered acceptable if the design meets 1 MSS STANDARD PRACTICE SP-87 the requirements of the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. 4.1.3 Calculations used to establish the design adequa
26、cy of fittings shall be made available to the purchaser upon request. 4.2 Design Proof Tests 4.2.1 Records of successful proof test shall contain at least the items shown in the following list. Records of such tests shall be made available at the facility for inspection by the purchaser. Items to be
27、 included in Records of Design Proof Tests. (Additional information may be included at Manufacturers option.) a) Fitting Type, nominal dimensions and material. (For example, 10 x 10 tee, Sched- ule 40, SA 234 WPB). b) Anticipated minimum thickness of the lightest production fitting. c) Actual minimu
28、m thickness of test fitting. d) Length, nominal wall thickness and material of each pipe attached to the test fitting for the test. e) Actual tensile strength of material used in the test fitting. f) Computed proof test pressure. g) Pressure gage identification and date of most recent calibration. h
29、) Maximum pressure applied in test. i) Rupture location, if rupture occurred. j) Date of test. k) Signature of manufacturers employee who witnessed the test. 4.2.2 Fittings that are representative of pro-duction shall be selected for test. The fitting shall not be thicker than 1.1 times the anticipa
30、ted thickness of the lightest production fitting. 4.2.3 Fittings, representative of production, selected for test shall be identified as to material, grade, and lot, including heat treatment. Straight seamless or welded pipe sections, whose calcu- lated bursting strength is at least as great as that
31、 calculated for the fitting, and not thicker than 1 times the nominal pipe wall, shall be welded to each end of the fitting to be tested. Any internal misalignment greater than 0.09 inch shall be reduced by taper boring at a slope not over 1:3. Length of straight pipe sections for closures shall be
32、at least twice the pipe O.D. Test fluid shall be water or other liquid used for hydrostatic testing. 4.2.4 Hydrostatic pressure shall be applied and increased until either rupture occurs or the pressure is 1.05 times the computed proof test pressure. The computed test pressure is defined by the equa
33、tion: Pc = computed proof test pressure, psi Sa = the actual tensile strength (in psi) of the material of the test fitting (de- termined on specimens representa- tive of the test fitting). t = nominal thickness of the matching pipe. Matching pipe is that pipe for which the fitting is recommended for
34、 use, inches. D = specified outside diameter of pipe, inches. For reducing fitting, t and D shall be taken for that matching pipe which gives the smaller value of t/ D. 4.2.5 Design adequacy is considered to be demonstrated if either rupture occurs at a pressure equal to or higher than Pcor if 1.05
35、Pcis held without rupture. 4.2.6 It is not necessary to conduct an indi- vidual test on fittings with all combinations of sizes, wall thickness, arc lengths and grades of steel. A successful proof test on one prototype fitting may represent others to the extent de- scribed herein, except a long radi
36、us elbow is not an acceptable prototype for a short radius elbow. 2 DtS 2Pca MSS STANDARD PRACTICE SP-87 4.2.7 One test fitting may be used to qualify a fitting of a similar design pattern no smaller than one-half nor larger than two times the size of the test fitting. 4.2.8 The test on a non-reduci
37、ng tee qualifies for reducing tees of the same design pattern manufactured from the same material thickness as the non-reducing tee. 4.2.9 The test on a reducer of a given reduc- tion qualifies for reducers of further reduction, manufactured from the same material thickness as the tested reducer. 4.
38、2.10 The untested fitting must have a t/D ratio not less than one-half nor more than two times the t/D ratio of the test fitting. 4.2.11 Proof tests which have been conducted prior to the issuance of this standard and which are equivalent to the above requirements shall be considered as fulfilling t
39、he requirements of this standard. 5. SIZE The “size“ of the fittings in the tables is identified by the corresponding “nominal pipe size.“ For fittings 14 in. and larger, the O.D. of the pipe corresponds with the nominal pipe. 6. MARKING Each fitting shall be permanently(1)marked in accordance with
40、MSS SP-25, and in addition show the following: a) Material (By means of identification symbols estab-lished for the respective grade in the appro-priate ASME specifications.) b) Standard - - SP-87 (1)Supplementary Note: Where steel stamps are used they should be low stress type and care should be ta
41、ken so that the marking is not deep enough to cause cracks or to reduce wall thickness of the fitting below the minimum allowed. 7. MATERIAL Wrought fittings covered by this standard shall be in accordance with ASME. Specifications SA234, SA403 and SA420 in conjunction with supplementary specificati
42、on SA652. 8. FITTINGS DIMENSIONS One of the principles of this standard is to establish overall dimensions. Dimensional standards for these fittings will be found in Tables 2 through 9. Overall dimensions for these fittings are the same as ANSI/ASME B16.9 and B16.28. Detailed dimensions for the bodi
43、es of fittings may vary from manufacturer to manu-facturer within the limitations of this standard. When required such dimensions shall be avail-able by agreement between the manufacturer and purchaser. 9. SHAPE REQUIREMENTS 9.1 90, 45 Elbows and 180 Returns 9.1.1 These shall be manufactured to appr
44、oxi- mate a continuous radius that provides the A dimension in Tables 2, 3, 4 and 5. 9.1.2 Out-of-roundness is defined as the dif- ference between maximum and minimum out- side diameters measured on any radial cross section. The maximum out-of-roundness throughout the body shall not exceed the tol-
45、erance given in Table 1. 9.1.3 The actual thickness of the elbows may not exceed 1.25 times the nominal wall, except as follows: a) For short radius elbows, since the nominal wall must be increased by 20% to com-pensate for shape, the actual thickness of this elbow may not exceed 1.5 times the nomin
46、al wall. b) For elbows with a counterbore or other close tolerance internal machining, the thickness must be increased to provide3 MSS STANDARD PRACTICE SP-87 material for these additional machining operations. For these elbows, thicknesses up to the next higher schedule than the nominal wall may be
47、 used. Where there is no next higher schedule the wall may not be thicker than 1.33 times the nominal wall. For short radius elbows, the next higher schedule above the adjusted nominal wall may be used, or where there is no next higher schedule the wall may not be thicker than 1.33 times the adjuste
48、d nominal-wall. 9.2 Tees 9.2.1 The outlet dimension M shown in Tables 6 and 7 shall not be less than indicated. The M dimension may be increased upon mutual agreement between purchaser and manufacturer. 9.2.2 The exterior of the transition surface between the run and outlet portions (external crotch
49、 radius) shall be smooth contoured and not less than 0.1 times the nominal outside diameter of the outlet pipe. 9.2.3 The minimum body wall thickness shall not be less than 0.875 times the nominal wall thickness of the matching run pipe, except that the area immediately adjacent to the outlet end (within a 2t length) cannot be less than 0.875 times the nominal wall thickness of the matching outlet pipe. 9.2.4 The actual thickness throughout the
