1、 MSS SP-53-2012 Quality Standard for Steel Castings and Forgings for Valves, Flanges, Fittings, and Other Piping Components Magnetic Particle Examination Method Standard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 127 Park Str
2、eet, NE Vienna, Virginia 22180-4602 Phone: (703) 281-6613 Fax: (703) 281-6671 E-mail: standardsmss-hq.org www.mss-hq.org MSS MSS STANDARD PRACTICE SP-53 i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 304 and the MSS Coordinating Committee. The content o
3、f this Standard Practice is 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
4、the manufacturer, the user, 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 docum
5、ents such as a code, specification, 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
6、to MSS and is solely the responsibility of the certifier or maker of the statement. “Unless indicated otherwise within this MSS Standard Practice, other standards documents referenced to herein are identified by the date of issue that was applicable to this Standard Practice at the date of approval
7、of this MSS Standard Practice (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
8、to the validity of any potential claim(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 responsibilit
9、y. In this Standard Practice, 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 co
10、nstrued as “supplemental”. Note that supplemental information does not include mandatory requirements. U.S. customary units in this Standard Practice are the standard; the SI (metric) units are for reference only. Substantive changes in this 2012 edition are “flagged” by parallel bars as shown on th
11、e margins of this paragraph. The specific detail of the change may be determined by comparing the material flagged with that in the previous edition. Non-toleranced dimensions in this Standard Practice are nominal unless otherwise specified. Excerpts of this Standard Practice may be quoted with perm
12、ission. Credit lines should read Extracted from MSS SP-53-2012 with permission of the publisher, Manufacturers Standardization Society of the Valve and Fittings Industry. Reproduction and/or electronic transmission or dissemination is prohibited under copyright convention unless written permission i
13、s granted by the Manufacturers Standardization Society of the Valve and Fittings Industry Inc. All rights reserved. MSS is a registered trademark of Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Originally Approved: January 1957 Originally Published: 1958 Edition Cur
14、rent Version Approved: October 2012 Current Version Published: December 2012 Copyright , 2012 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. MSS STANDARD PRACTICE SP-53 ii FOREWORD Historically, magnetic particle inspection has been applied to ste
15、el castings since the mid-1900s. It became regarded as an aid to the manufacture of steel castings, particularly pressure containing castings, for use in “severe services”. The application of magnetic particle inspection had progressed to the point of recognition in 1944, warranting the issuance by
16、ASTM of its method of “Magnetic Particle Testing and Inspection of Commercial Steel Castings“, known as ASTM A272-44 (withdrawn in 1945). It had been the practice of manufacturers and users of steel castings to survey castings for the type of defects as revealed by the procedures and to reach agreem
17、ent on the extent and areas for which this procedure was to be used. There had been no standard establishing a dividing line between acceptable magnetic particle indications and those requiring probing or further exploration. In the mid-1950s, there was an increasing demand on the part of certain us
18、ers of steel valves, fittings, and flanges, particularly in the oil refining industry, to establish minimum requirements for freedom from discontinuities of the type revealed by magnetic particle tests. As the demand for such a quality level grew, it has become apparent that some uniform code of acc
19、eptance would have to be developed beyond the mere procedure for making the inspection. To this end the ASTM has promulgated E125, “Reference Photographs for Magnetic Particle Indications on Ferrous Castings“. These photographs typify the type, character, and extent of indication relative to the qua
20、lity definitions embraced in this MSS Standard Practice. The reference photographs were originally obtained by a procedure in accordance with ASTM E109, “Method for Dry Powder Magnetic Particle Inspection”, which replaced ASTM A272 in regards to the type of castings covered herein are concerned. Not
21、e that ASTM E109 was eventually withdrawn in 1981 and subsequently replaced by ASTM E709. The original selection of photographs and their interpretation was undertaken by the Steel Founders Society of America and were made available to ASTM Committee E-7 for the purpose of establishing the “Referenc
22、e Photographs“. These reference photographs served a parallel purpose to ASTM E7l, “Industrial Radiographic Standards for Steel Castings“, originally prepared by the Navy Departments Bureau of Ships as reference for repair and/or acceptance of steel castings upon a basis of radiographic inspections.
23、 Thus, the magnetic particle reference photographs were treated as another type of “go-no-go“ gage in defining the original criteria established within this MSS Standard Practice. Note that ASTM E71 was withdrawn in 1974 and subsequently replaced by ASTM E446. The MSS SP-53 was originally approved i
24、n January 1957. Complying with MSS SP-53 serves to codify a quality level in cast steel valves, fittings, and flanges involving casting discontinuities to an extent beyond that which may be attained through visual inspection. The quality herein implied is the minimum consideration of safety for the
25、services in which such castings are to be used. There is no implication intended that “visual quality inspection“ of steel casting will not fully support the ratings and requirements of ASME B16.5. The ASTM E125 Reference Photographs were originally adopted at the prompting of a Joint Task Force pro
26、moted by Subcommittee 3, of ASA (later known as ANSI) Standards Committee B31, on Refinery Piping Systems; consisting of representatives of ASA, Steel Founders Society of America (SFSA), ASTM, ASME, and MSS. In addition, the aforementioned Standards Committee B31(developer of the standard known toda
27、y as ASME B31 or the American National Standard Code for Pressure Piping), involving the section in B31 relating to Refinery Piping Systems, was concerned with pressure castings and expressed interest in MSS SP-53, given its scope and examination applicability. It was then contemplated during this t
28、ime that MSS SP-53 would be employed by the B31 Refinery group as a “practical vehicle whereby the Pressure Piping Codes safe practice precepts may be exerted over the steel castings used in the manufacture of valves, fittings, and flanges”. This Forward is informational and provides a historical pe
29、rspective on the subject. MSS acknowledges the original assistance and collaboration involving MSS SP-53 by the supporting members of the former ASA Standards Committee B31 as mentioned above. MSS STANDARD PRACTICE SP-53 iii TABLE OF CONTENTS SECTION PAGE 1 SCOPE . 1 2 DEFINITIONS . 1 3 PROCEDURES .
30、 1 4 ACCEPTANCE STANDARDS . 1 5 REFERENCE PHOTOGRAPHS . 1 6 REMOVAL AND REPAIR OF DISCONTINUITIES 2 TABLE 1 Acceptance Standards 3 ANNEX A Referenced Standards and Applicable Dates 4 MSS STANDARD PRACTICE SP-53 1 QUALITY STANDARD FOR STEEL CASTINGS AND FORGINGS FOR VALVES, FLANGES, FITTINGS, AND OTH
31、ER PIPING COMPONENTS MAGNETIC PARTICLE EXAMINATION METHOD 1. SCOPE 1.1 This Standard Practice provides methods and acceptance standards for magnetic particle examination of ferritic steel valves, flanges, fittings, and other piping components by use of dry magnetic powder or wet magnetic particles.
32、It is applicable to the examination of repairs and the initial examination of castings and forgings. 1.2 The methods contained in this Standard Practice provide uniform procedures that will produce satisfactory and consistent results upon which the acceptance standards of Table 1 may be used. 1.3 Th
33、is examination guide may be used on a voluntary basis or when specified in an inquiry, contract, or order and when mutually agreed upon by the manufacturer and the purchaser. 1.4 This Standard Practice includes the examination of pressure containing castings and forgings. 2. DEFINITIONS 2.1 Pressure
34、 Containing Piece A piece whose failure would permit the contained fluid to escape to the atmosphere. For valves, the body, bonnet (cover), and end pieces (of multi-piece valve bodies, e.g., ball valves) shall be considered the pressure containing pieces. 2.2 Indication A detectable magnetic particl
35、e accumulation resulting from a distortion of the magnetic field. 2.3 Linear Indication An indication in which the length is more than three times the width. 2.4 Rounded Indication An indication which is circular or elliptical with its length less than three times its width. 2.5 Standard Definitions
36、 See ASTM E1316, “Standard Terminology for Nondestructive Examinations”; relating to magnetic particle inspection and examination. 3. PROCEDURE 3.1 All exterior and accessible interior surfaces of the pressure containing parts shall be examined by the magnetic particle method. Examination may occur
37、prior to machining or after machining at the manufacturers option. This Standard Practice may also be used for examination of other parts when mutually agreed upon by the manufacturer and the purchaser. 3.2 Magnetic particle procedures and personnel qualification requirements for casting examination
38、 shall be in accordance with ASTM E709. For forgings, the examination procedures and personnel qualification requirements shall be in accordance with ASTM A275/A275M. 4. ACCEPTANCE STANDARDS 4.1 Acceptance Standards for magnetic particle indications shall be as shown in Table 1. 5. REFERENCE PHOTOGR
39、APHS 5.1 Typical Magnetic Particle Indications are shown in ASTM E125, Reference Photographs for Magnetic Particle Indications on Ferrous Castings. 5.2 Indications of weld discontinuities illustrated in ASTM E125 are merely examples of discontinuities in weld repairs and are not indicative of the de
40、gree of severity. MSS STANDARD PRACTICE SP-53 2 5.3 The reference examples of false indications and magnetic anomalies, illustrated in ASTM E125, are necessary as a guide to the type of indications and not necessarily indicative of any conditions concerning integrity or usefulness under the scope of
41、 quality defined within this Standard Practice. It is recognized, that in some instances, surveys by methods other than magnetic particle examination may be necessary to establish what indications belong to these reference categories. 6. REMOVAL AND REPAIR OF DISCONTINUITIES 6.1 Piping parts and com
42、ponents rejected through the application of these standards may be repaired. If welding is required, it shall be performed by qualified personnel and in accordance with requirements specified in the applicable steel casting or forging specification. 6.2 Discontinuities in excess of those represented
43、 by acceptable indications shall be removed by suitable means. If removal of surface discontinuities to an acceptable level does not result in reducing the wall thickness below the acceptable minimum, the area shall be blended smoothly into the surrounding surface. Where removal of discontinuities r
44、esults in a wall thickness below the acceptable minimum, the resultant cavity may be repaired by welding. Welded areas shall be blended smoothly into the surrounding surface. 6.3 Areas which as a result of magnetic particle examination, have been weld repaired or from which discontinuities have been
45、 removed without requirement for weld repair, shall be re-examined by the magnetic particle method. 6.4 The acceptance standards for magnetic particle re-examination required under Section 6.3 shall be as shown in Table 1. MSS STANDARD PRACTICE SP-53 3 TABLE 1 Acceptance Standards A. CASTINGS Maximu
46、m acceptable indications are as follows: 1. Linear indications (as defined in Section 2.3) 0.3 in. (8 mm) long for materials up to 0.5 in. (13 mm) thick 0.5 in. (13 mm) long for materials 0.5 in. to 1 in. (13 mm to 25 mm) thick 0.7 in. (18 mm) long for materials over 1 in. (25 mm) thick Linear indic
47、ations must be separated by a distance greater than the length of the longest, adjacent acceptable linear indication. 2. Rounded indications (as defined in Section 2.4) 0.3 in. (8 mm) diameter for materials up to 0.5 in. (13 mm) thick 0.5 in. (13 mm) diameter for materials over 0.5 in. (13 mm) thick
48、 Four or more rounded indications in a line separated by 0.06 in. (2 mm) or less edge-to-edge are unacceptable, unless the total length does not exceed the individual diameter size allowed for the material thickness being evaluated. B. FORGINGS Maximum acceptable indications are as follows: 1. Linea
49、r indications (as defined in Section 2.3) 0.2 in. (5 mm) long for materials 0.5 in. (13 mm) or less thick 0.4 in. (10 mm) long for materials 0.5 in. to 1 in. (13 mm to 25 mm) thick 0.6 in. (15 mm) long for materials over 1 in. (25 mm) thick Linear indications must be separated by a distance greater than the length of the longest, adjacent acceptable linear indication. 2. Rounded indications (as defined in Section 2.4) 0.2 in. (5 mm) diameter for materials up to 0.5 in. (13 mm) thick 0.3 in. (8 mm) diameter for materials over 0.5 in. (13 mm) thick Four or more rounded indications
