1、 ANSI/MSS SP-55-2011 Quality Standard for Steel Castings for Valves, Flanges, Fittings, and Other Piping Components Visual Method for Evaluation of Surface Irregularities Reference Version (Not for Inspection) Standard Practice Developed and Approved by the Manufacturers Standardization Society of t
2、he Valve and Fittings Industry, Inc. 127 Park Street, NE Vienna, Virginia 22180-4602 Phone: (703) 281-6613 Fax: (703) 281-6671 E-mail: standardsmsshq.org www.msshq.org ANSI/MSS STANDARD PRACTICE SP-55i This MSS Standard Practice was developed under the consensus of the MSS Technical Committee 304 an
3、d the MSS Coordinating Committee. In addition, this Standard Practice was approved by an ANSI/MSS Consensus Committee and by ANSI as an American National Standard. The content of this Standard Practice is the resulting efforts of competent and experienced volunteers to provide an effective, clear, a
4、nd 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, and the general public. The existence of an MSS Standard Practice does not in itself preclude t
5、he 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, specification, sales contract, or public law, as applicable. MSS has no power, nor does it undertake,
6、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 responsibility of the certifier or maker of the statement. “Unless indicated otherwise within thi
7、s 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 of this MSS Standard Practice (see Annex A). This Standard Practice shall remain silent on the validity of those other sta
8、ndards 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 potential claim(s) or of any patent rights in connection therewith. MSS shall not be held responsib
9、le 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 text, notes, annexes, tables, figures, and references are construed to be essential to t
10、he 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”. Note that supplemental information does not include mandatory requirements. Substantive changes
11、 in this 2011 edition are “flagged” by parallel bars as shown on the margins of this paragraph. The specific detail of the change may be determined by comparing the material flagged with that in the previous edition. U.S. customary units in this Standard Practice are the standard; SI (metric) units
12、are for reference only. Non-toleranced dimensions in this Standard Practice are nominal, and, unless otherwise specified, shall be considered “for reference only”. Excerpts of this Standard Practice may be quoted. Credit lines should read Extracted from ANSI/MSS SP-55-2011 with permission of the pub
13、lisher, Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. 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 Ind
14、ustry, Inc. All rights reserved. Originally Published: April 1961 Current Edition Approved by MSS: September 2010 Current Edition Approved by ANSI/MSS Consensus Committee: August 2011 Current ANSI/MSS Edition Published: October 2011 MSS is a trademark of the Manufacturers Standardization Society of
15、the Valve and Fittings Industry, Inc. Copyright , 2011 by Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. Printed in U.S.A. ANSI/MSS STANDARD PRACTICE SP-55ii FOREWORD The MSS SP-55, Quality Standard for Steel Castings for Valves, Flanges, Fittings, and Other Piping Co
16、mponents Visual Method for Evaluation of Surface Irregularities, was originally adopted in 1961. It was developed forthe purpose of providing the industry with a uniform means for identifying various types of casting surface irregularities. A set of 60 reference photographs illustrating these castin
17、g surface irregularities is included in this Standard Practice to permit a visual comparison of an actual casting surface with the reference photographs for the purpose of the establishing acceptable/unacceptable casting surface irregularities. The format of this Standard Practice was revised in 199
18、6 to be consistent with other MSS Standard Practices. The 2006 revised edition included updates in the referenced standards, Annex A, to reflect current applicable dates and the updated addresses of the referenced publications organizations. This 2011 revised American National Standard edition inclu
19、des updates to the applicable organizations and referenced standards, indicating current dates, names, and addresses of the referenced publications or organizations within this Standard Practice. In addition, an Annex B has been introduced that contains the pre-existing set of 60 reference photograp
20、hs, along with various editorial corrections that include Section 5. IMPORTANT NOTICE: MSS PDF Reference Version Due to variations in viewing environments, the printed version published by MSS, or its Authorized Distributors, shall be the “Official” Rendering of this Standard Practice for inspection
21、, code application, or any other purpose. This Electronic (PDF) version is for REFERENCE ONLY. ANSI/MSS STANDARD PRACTICE SP-55iii TABLE OF CONTENTS SECTION PAGE 1 SCOPE 1 2 DEFINITION OF SURFACE QUALITY BY VISUAL INSPECTION 1 3 REFERENCE PHOTOGRAPHS 1 4 TERMINOLOGY FOR REFERENCE PHOTOGRAPHS . 1 5 C
22、OMPARISON OF MSS SP-55 ACCEPTANCE CRITERIA WITH CTI COMPARATORS COVERING SURFACE TEXTURE QUALITY STANDARDS 2 TABLE 1 Acceptance Levels in the CTI Comparators Considered Equivalent to the Acceptance Criteria of MSS SP-55 . 3 ANNEX A Referenced Standards and Applicable Dates 4 B Type I through XII Acc
23、eptable and Unacceptable Reference Photographs . 6 ANSI/MSS STANDARD PRACTICE SP-55iv This Page Intentionally Left Blank Manufacturers Standardization Society of the Valve and Fittings Industry ANSI/MSS STANDARD PRACTICE SP-551 1. SCOPE1.1 This Standard Practice is intended to supplement the require
24、ments of ASTM Standard Specifications A216/A216M, A217/A217M, A351/A351M, A352/A352M, A389/A389M, A487/A487M, and A744/A744M, and to provide a series of reference photographs typical of the various surface irregularities common to steel pressure castings and illustrations of generally acceptable and
25、 generally rejectable quality. Table 1 of Section 5 is provided to show MSS interpretation as to the relationship between this Standard Practice and the levels of surface quality illustrated by the comparators and the associated photographs of the Castings Technology International (CTI), “Comparator
26、s for the Definition of Surface Quality of Steel Castings”. 1.2 For additional nondestructive examinations defining quality of steel castings, this Standard Practice may be supplemented by the following MSS Standard Practices: SP-53, “Magnetic Particle Examination Method”; SP-54, “Radiographic Exami
27、nation Method”; SP-93, “Liquid Penetrant Examination Method”; SP-94, “Ultrasonic Examination Method”; and SP-112, “Visual and Tactile Method”. 2. DEFINITION OF SURFACE QUALITYBY VISUAL INSPECTION2.1 Twelve general types of surface irregularities are characterized in the collection (see Section 3) wi
28、th five examples being included for each type. The two examples in each case shown to the left illustrate acceptable degrees of the particular type of irregularity. The three examples to the right are characterized as containing unacceptable defects. 2.2 It is recognized that problems may be encount
29、ered in evaluating surfaces of castings over a wide range of size and section thickness using the same set of standards. This guide attempts to minimize the size effect and is intended for general use for any 4 in. x 5 in. (100mm x 125mm) area. 3. REFERENCE PHOTOGRAPHS3.1 A set of 60 reference photo
30、graphs illustrating various casting surface irregularities, which can be observed by visual inspection, is included herewith (see Annex B). These photographs are actual size examples of gradations involving acceptable and non-acceptable irregularities. It is intended that irregularities less pronoun
31、ced than those shown as non-acceptable shall be accepted under this guide. 3.2 Photographs included are of actual castings and may exhibit surface irregularities other than the type characterized in the heading. Each type of surface irregularity shall be judged only against the series of photographs
32、 identified with the type. 4. TERMINOLOGY FOR REFERENCEPHOTOGRAPHS4.1 It should be noted that all definitions and discussions of terminologies apply only to surface irregularities and not to internal defects. The types of surface irregularities illustrated in the reference photographs are as follows
33、: a) Type I Hot Tears and CracksLinear surface discontinuities orfractures caused by either internal orexternal stresses or a combination ofboth acting on the casting. They mayQUALITY STANDARD FOR STEEL CASTINGS FOR VALVES, FLANGES, FITTINGS, AND OTHER PIPING COMPONENTS VISUAL METHOD FOR EVALUATION
34、OF SURFACE IRREGULARITIES ANSI/MSS STANDARD PRACTICE SP-552 occur during, or subsequent to, solidification. In general, visible surface cracks or hot tears, or both, are not acceptable. b) Type II ShrinkageA void left in cast metal as a result ofsolidification shrinkage and theprogressive freezing o
35、f metal, which isexposed upon cutting off risers andgates.c) Type III Sand InclusionsSand that becomes entrapped in themolten metal and shows on the surfaceof the casting.d) Type IV Gas PorosityVoids in cast metal caused byentrapment of gas during solidification.e) Type V VeiningFeatures on the surf
36、ace of castingsappearing as a ridge and associated withmovement or cracking of sand.f) Type VI Rat TailsFeatures on the surface of castingsappearing as a depression resulting fromfaulting or buckling of the moldsurfaces.g) Type VII Wrinkles, Laps, Folds andCold ShutsSurface irregularities caused byi
37、ncomplete fusing or by folding ofmolten metal surfaces.h) Type VIII Cutting MarksIrregularities in casting surfacesresulting from burning or mechanicalmeans used in the cleaning of castings.i) Type IX ScabsSlightly raised surface blemishes thatare usually sand crusted over by a thinporous layer of m
38、etal.j) Type X ChapletsEvidence of chaplets on surface ofcasting disclosing incomplete fusion,which likewise can apply to internalchills.k) Type XI Weld Repair AreasEvidence of improper surfacepreparation after welding.l) Type XII Surface RoughnessSurface texture due to design, pattern,gating, and s
39、and conditions.5. COMPARISON OF MSS SP-55ACCEPTANCE CRITERIA WITH CTICOMPARATORS COVERINGSURFACE TEXTURE QUALITYSTANDARDS5.1 MSS and other societies have published standards illustrating various levels of surface texture and irregularities classified by type. 5.2 Table 1 has been included for the pu
40、rpose of showing MSS interpretation as to the levels of discontinuity by type, which would be met by castings conforming to MSS SP-55. 5.3 The CTI Comparators are plastic replicas of actual casting surfaces, each of which is also represented by a photograph of the replica. 5.4 MSS SP-55 acceptance c
41、riteria have been reviewed against the CTI Comparators to designate the acceptance criteria of each type, which are equivalent to MSS SP-55 acceptance criteria. Comparisons published in Table 1 represent the MSS interpretation. They are intended to be of assistance to those interpreting the CTI Comp
42、arators (1). (1) The CTI surface comparators for steel castings discussed in Section 5 do not identify specific levels as being acceptable. Such issues are left to the product specification or contract. ANSI/MSS STANDARD PRACTICE SP-553 TABLE 1 Acceptance Levels in the CTI Comparators Considered Equ
43、ivalent to the Acceptance Criteria of MSS SP-55 MSS SP-55 CLASSIFICATION CTI COMPARATORS EQUIVALENT TYPE I Hot tears and cracks (None acceptable) None Acceptable TYPE II Shrinkage NO EXAMPLES Use MSS SP-55 TYPE III Sand Inclusions B2 or better TYPE IV Gas Porosity C2 or better TYPE V Veining NO EXAM
44、PLES Use MSS SP-55 TYPE VI Rat Tails NO EXAMPLES Use MSS SP-55 TYPE VII Wrinkles, Laps, Folds, and Cold Shuts D2 or better TYPE VIII Cutting Marks G2 or better H4 or better TYPE IX Scabs E1 or better TYPE X Chaplets F2 or better TYPE XI Weld Repair Areas J3 or better TYPE XII Surface Roughness A3 or
45、 better ANSI/MSS STANDARD PRACTICE SP-554 ANNEX A Referenced Standards and Applicable Dates This Annex is an integral part of this Standard Practice and is placed after the main text and before Annex B (Photographs) for convenience. Standard Name Description ASTM; ANSI/ASTM Standard Specification fo
46、r: A216/A216M-08 Steel Castings, Carbon, Suitable for Fusion Welding, for High-Temperature Service A217/A217M-10 Steel Castings, Martensitic Stainless and Alloy, for Pressure-Containing Parts, Suitable for High-Temperature Service A351/A351M-10 Castings, Austenitic, for Pressure-Containing Parts A35
47、2/A352M-06 Steel Castings, Ferritic and Martensitic, for Pressure-Containing Parts, Suitable for Low-Temperature Service A389/A389M-10 Steel Castings, Alloy, Specially Heat-Treated, for Pressure-Containing Parts, Suitable for High-Temperature Service A487/A487M-93(2007) Steel Castings Suitable for P
48、ressure Service A744/A744M-10 Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe Service MSS SP-53-1999 (R 2007) Quality Standard for Steel Castings and Forgings for Valves, Flanges, and Fittings and Other Piping Components Magnetic Particle Examination Method SP-54-1999 (R 2007) Qualit
49、y Standard for Steel Castings for Valves, Flanges and Fittings and Other Piping Components Radiographic Examination Method SP-93-2008 Quality Standard for Steel Castings and Forgings for Valves, Flanges, Fittings, and Other Piping Components Liquid Penetrant Examination Method SP-94-2008 Quality Standard for Ferritic and Martensitic Steel Castings for Valves, Flanges, Fittings, and Other Piping Components Ultrasonic Examination Method SP-112-2010 Quality Standard for Evaluation of Cast Surface Finishes Visual and Tactile Method CTI Comparators for the D
