SOUTH AFRICAN NATIONAL STANDARD

Transcription

1 ISBN Any reference to SABS is deemed to be a reference to this standard (Government Notice No of 8 November 2002) SOUTH AFRICAN NATIONAL STANDARD Check valves (flanged and wafer types) Part 1: PN series Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001 Tel: Fax: SABS

2 Table of changes Change No. Date Scope Amdt Amended to update normative references, to change certain definitions, to add to the trim material, to change the requirements for the leakage rate of valves, to change the allowable material used for valves and valve components, to change the requirements for flanges of valves and to allow for agreed additional features on valves. Amdt Amended to change the designation of SABS standards to SANS standards, to update the definition of "acceptable and to update referenced standards. Acknowledgement The SABS Standards Division wishes to acknowledge the valuable assistance derived from publications of the American National Standards Institute. Foreword This South African standard was approved by National Committee SABS/TC 138/SC 04, Water and sanitation Equipment and systems Metallic pipes and fittings, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in February This document supersedes SABS :2000 (edition 1.1). A vertical line in the margin shows where the text has been technically modified by amendment No. 2. SANS 1551 consists of the following parts, under the general title Check valves (flanged and wafer types): Part 1: PN series. Part 2: Class series. Annex A (Notes to purchasers) forms an integral part of this document. Annex B (Quality verification of check valves) and annex C (Bibliography) are for information only. Reaffirmed and reprinted in June This document will be reviewed every five years and be reaffirmed, amended, revised or withdrawn.

3 Contents Page Acknowledgement Foreword 1 Scope Normative references Definitions Wafer and flanged check valves General requirements Wafer check valves Specific requirements Flanged check valves Specific requirements Marking Methods of test Hydraulic test Seat leakage test for resilient seated check valves Annex A (normative) Notes to purchasers Annex B (informative) Quality verification of check valves Annex C (informative) Bibliography

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5 Check valves (flanged and wafer types) Part 1: PN series 1 Scope 1.1 This part of SANS 1551 specifies the characteristics of cast iron swing-type check valves (wafer or flanged type) that have a nominal size in the range 40 mm to 600 mm and that are intended for general hydraulic (water, air, gas or petroleum) applications at working pressures of up to kpa and at temperatures not exceeding 120 C (but see 1.2). 1.2 Subject to appropriate modifications or pressure/temperature deratings (see BS EN or BS EN ), valves that comply with the requirements of this part of SANS 1551 can be used at temperatures exceeding 120 C. Amdt 1; amdt 2 NOTE The PN series of check valves are designed to be used in conjunction with flanges that comply with the relevant requirements of BS EN Amdt This part of SANS 1551 does not purport to address all of the safety problems associated with the use of check valves in hazardous environments. It is the responsibility of the user of this part of SANS 1551 to establish appropriate safety and health practices and to implement any applicable regulations. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of SANS All standards are subject to revision, and, since any reference to a standard is deemed to be a reference to the latest edition of that standard, parties to agreements based on this part of SANS 1551 are encouraged to take steps to ensure the use of the most recent editions of the standards indicated below. Information on currently valid national and international standards can be obtained from the SABS Standards Division. ASTM A 802/A802M, Standard practice for steel castings Surface acceptance standards visual examination. BS 970-1, Wrought steels for mechanical and allied engineering purposes Part 1: General inspection and testing procedures and specific requirements for carbon, carbon manganese, alloy and stainless steels. Amdt 2 BS 970-4, Wrought steels for mechanical and allied engineering purposes Part 4: Valve steels. Amdt 2 3