MSS-SP-锻制不锈钢对焊管件-.pdf

MSS SP-43-2008Wrought and Fabricated Butt-Welding Fittings for Low Pressure,Corrosion Resistant ApplicationsStandard Practice Developed and Approved by the Manufacturers Standardization Society of the Valve and Fittings Industry,Inc.127 Park Street,NE Vienna,Virginia 22180 Phone:(703)281-6613 Fax:(703)281-6671 Email:infomss-hq.orgwww.mss-hq.orgMSSSTANDARD PRACTICESP-43iThis 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 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 MSS 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.Unless otherwise specifically noted in this MSS SP,any standard referred to herein is identified by the date of issue that was applicable to the referenced standard(s)at the date of issue of this MSS SP.(See Annex A).This document has been substantially revised from the previous 1991(R 2001)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 made of this document with the previous edition.Any part of this Standard Practice may be quoted.Credit lines should read Extracted43 2008 from MSS SP-,with permission of the publisher,the Manufacturers Standardization Society.Reproduction prohibited under copyright convention unless written permission is granted by the Manufacturers Standardization Society of the Valve and Fittings Industry,Inc.Originally Approved October,1950 Copyright 1982 by Manufacturers Standardization Society of the Valve and Fittings Industry,Inc.Printed in U.S.A.MSSSTANDARD PRACTICESP-43iiFOREWORDASME B16.9 is the American Standard for steel butt-welding fittings and although not so stated,it is implied that its scope deals primarily with the schedules of wall thicknesses which are common to carbon steel and the grades of alloy steel piping that are selected for pressure and temperature considerations.The rapid expansion of the process industries in the field of chemicals,plastics,textiles,etc.,has created a demand for a class of pipe referred to as stainless piping,using this word in its generic sense.This field employs the use of the austenitic stainless steels and also nickel and its related alloys.This stainless piping is used with resistance to corrosion,elimination of product contamination,or combination of the two as the principle reason for material selection.Pressure is seldom,if ever,a critical consideration.When pressure is a consideration reference is made to ASME B16.9.Mechanical strength,resistance to vacuum,and economy,are the most usual criteria in the selection of pipe thickness in this field,and for this reason the wall thicknesses employed in the field of corrosion resistant pipe are lighter than those in common usage with carbon steel piping.In 1949 ANSI approved standard B36.19 Stainless Steel Pipe in which a schedule of wall thickness was established and designated as Schedule 10S.Numerous companies were also using a wall thickness lighter than Schedule 10S for services where contamination rather than corrosion was the prime consideration.These lighter wall thicknesses were designated Schedule 5S and the original 1950 edition of SP-43 established a series of Schedule 5S fittings.The 5S thicknesses were published in SP-43 and were developed in cooperation with representatives of the various principal chemical companies and processing industries.In 1952 the Stainless Steel Pipe Standard B36.19 was revised to recognize the Schedule 5S wall thickness pipe as American Standard.The purpose of this Standard Practice is to provide industry with a set of dimensional standards for butt-welding fittings that can be used with these light wall pipes of corrosion resisting materials.The center-to-end dimensions of all fittings are identical with those in ASME B16.9 which give to industry the advantage of uniform design room practice and a maximum utilization of existing die equipment.The only departure from this is in the lap-joint stub end where for purposes of economy the face-to-end of the product has been reduced for use with thin wall piping.The advantage of longer center-to-end dimensions of the size 3/4 elbows resulted in the change in the tables to permit a gradual changeover,providing the manufacturers ample time to deplete existing stocks,re-tool and replenish stocks.The 1991 revision of the SP was required to delete the metric equivalents.The 2001 Reaffirmation had no technical changes.There were minor e。