1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-20764-9 SANS 1551-1:2008Edition 1.2Any reference to SABS 1551-1 is deemedto be a reference to this standard(Government Notice No. 1373 of
4、8 November 2002)SOUTH AFRICAN NATIONAL STANDARD Check valves (flanged and wafer types) Part 1: PN series Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Afr
5、ica SANS 1551-1:2008 Edition 1.2 Table of changes Change No. Date Scope Amdt 1 2000 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 valv
6、e components, to change the requirements for flanges of valves and to allow for agreed additional features on valves. Amdt 2 2008 Amended to change the designation of SABS standards to SANS standards, to update the definition of “acceptable” and to update referenced standards. Acknowledgement Standa
7、rds South Africa 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 StanSA SC 5120.12E, Water and sanitation Equipment and systems Reticulation valves, in accord
8、ance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This document was published in February 2008. This document supersedes SABS 1551-1:2000 (edition 1.1). A vertical line in the margin shows where the text has been technically modified by amendment No
9、. 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
10、for information only. SANS 1551-1:2008 Edition 1.2 1 Contents Page Acknowledgement Foreword 1 Scope . 3 2 Normative references . 3 3 Definitions 4 4 Wafer and flanged check valves B General requirements . 5 5 Wafer check valves B Specific requirements . 11 6 Flanged check valves B Specific requireme
11、nts 13 7 Marking 15 8 Methods of test 15 8.1 Hydraulic test 16 8.2 Seat leakage test for resilient seated check valves 16 Annex A (normative) Notes to purchasers . 18 Annex B (informative) Quality verification of check valves 19 Annex C (informative) Bibliography 19 SANS 1551-1:2008 Edition 1.2 2 Th
12、is page is intentionally left blank SANS 1551-1:2008 Edition 1.2 3 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
13、 mm and that are intended for general hydraulic (water, air, gas or petroleum) applications at working pressures of up to 2 500 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 1092-3 or BS EN 1092-2), va
14、lves 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 1092-3. Amdt 21.3 This part of SANS
15、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
16、references The following standards contain provisions which, through reference in this text, constitute provisions of this part of SANS 1551. 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 a
17、greements 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 Standards South Africa. ASTM A 802/A802M, Standard practice
18、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 s
19、teels for mechanical and allied engineering purposes Part 4: Valve steels. Amdt 2 SANS 1551-1:2008 Edition 1.2 4 BS EN 1092-2, Flanges and their joints Circular flanges for pipes, valves, fittings and accessories, PN designated Part 2: Cast iron flanges. Amdt 2 BS EN 1092-3, Flanges and their joints
20、 Circular flanges for pipes, valves, fitting and accessories, PN designated Part 1: Copper alloy flanges. Amdt 2 BS EN 1561, Founding Grey cast irons. Amdt 1 BS EN 1563, Spheroidal graphite cast iron. Amdt 1 BS EN 1982, Copper and copper alloys. Ingots and castings. Amdt 1 BS 4504-3-3.1, Circular fl
21、anges for pipes, valves and fittings (PN designated) Part 3: Steel, cast iron and copper alloy flanges Section 3.1: Specification for steel flanges. Amdt 2 BS 4504-3-3.2, Circular flanges for pipes, valves and fittings (PN designated) Part 3: Steel, cast iron and copper alloy flanges Section 3.2: Sp
22、ecification for cast iron flanges. Amdt 2 BS EN 10083-1, Steels for quenching and tempering Part 1: General technical delivery conditions. Amdt 2 BS EN 10090, Valve steels and alloys for internal combustion engines. Amdt 2 BS EN 12164, Copper and copper alloys Rod for free machining purposes. Amdt 1
23、 BS EN 12165, Copper and copper alloys Wrought and unwrought forging stock. Amdt 1 SANS 936/937 (SABS 936/937), Spheroidal graphite iron castings and austenitic spheroidal graphite iron castings. SANS 1034 (SABS 1034), Grey iron castings. SANS 1123, Pipe flanges. Amdt 1 SANS 1700, Fasteners. Amdt 1
24、3 Definitions For the purposes of this part of SANS 1551, the following definitions apply: 3.1 acceptable acceptable to the authority administering this standard, or to the parties concluding the purchase contract, as relevant Amdt 1; amdt 2 3.2 agreed agreed upon in writing in the order or contract
25、 Amdt 1 3.3 flanged check valve a check valve that has flanged ends and is intended to be connected to pipe flanges by means of individual bolts SANS 1551-1:2008 Edition 1.2 5 3.4 nominal pressure (PN) a numerical designation that is a convenient round number for reference purposes. All equipment of
26、 the same nominal size (DN) and designated by the same PN number shall have compatible rating dimensions 3.5 nominal size (DN) a numerical designation of bore that is common to all components in a piping system other than components designated by outside diameter or by thread size. It is a convenien
27、t round number for reference purposes and is only loosely related to manufacturing dimensions. It is designated by the letters DN followed by a number 3.6 test pressure a pressure equal to 1,5 times the working pressure 3.7 wafer check valve a check valve primarily intended for clamping between pipe
28、 flanges by means of through-bolts Amdt 1 3.8 working pressure the designed maximum allowable non-shock operating pressure of a valve at the specified operating temperature Amdt 1 4 Wafer and flanged check valves General requirements 4.1 Rating A valve shall be of one of the following ratings, as re
29、quired: a) PN10: for a working pressure not exceeding 1,0 MPa; b) PN16: for a working pressure not exceeding 1,6 MPa; and c) PN25: for a working pressure not exceeding 2,5 MPa. 4.2 Materials 4.2.1 Metallic materials Metallic materials used in the manufacture of components of a valve (including bolts
30、 and nuts) shall comply with the relevant requirements given in columns 3 and 4 (or, if so agreed upon, in columns 6 and 7) of table 3(a), 3(b) or 3(c), as appropriate. When similar metals are used for mating components that move relative to one another, the Vickers hardness of the materials of the
31、components shall differ by at least 40 units. 4.2.2 Non-metallic materials Non-metallic materials used for gland packings, the seating material of doors and the sealing material for body joints shall be suitable for use at a temperature in the range 0 C to 120 C (but see 1.2) and shall a) not consti
32、tute a toxic hazard; SANS 1551-1:2008 Edition 1.2 6 b) not support microbiological growth; and c) not give rise to unpleasant taste(s) or odour(s). 4.2.3 Valve trim materials Valve trim materials shall comply with the relevant requirements given in columns 3 and 4 (or, if so agreed upon, in columns
33、6 and 7) of table 3(a), 3(b) or 3(c), as appropriate. If the above materials are not used, the materials that are used shall be acceptable. Amdt 1 4.3 Design and construction 4.3.1 Door action A door shall operate freely either under its own weight (applicable only to single door valves) or, if so r
34、equired, under the action of an acceptable stainless steel door return spring (or springs). 4.3.2 Door seat rings The method of fixing loose door seat rings shall be as agreed upon. Fixing screws (if any) shall be of corrosion-resistant material. 4.3.3 Lifting eyes for valve bodies A valve of mass e
35、xceeding 20 kg shall have a replaceable lifting eye (or eyes) so positioned that the mounting of the valve in its intended orientation is ensured. 4.3.4 Construction The construction of a valve shall be such that, when the valve is tested in accordance with a) 8.1.2.1(a), there is no leakage or swea
36、ting through the body of the door(s), b) 8.1.2.1(b), the door(s) and the door mechanism(s) do not suffer any damage that may affect the operation of the valve; c) 8.1.2.2, for metal seated check valves, there is no water leakage past the seats in excess of that given in column 2 of table 1 for the n
37、ominal size given in column 1; d) 8.1.2.3, for all check valves, there is no leakage or sweating through the body or through any joint on the body and no part of the valve fails; and e) 8.2, for resilient seated check valves, the leakage rate does not exceed the water flowrate given in column 3 or t
38、he gas flowrate given in column 2 of table 2, appropriate to the nominal size given in column 1. SANS 1551-1:2008 Edition 1.2 7 Table 1 Maximum permissible water leakage rate for metal seated check valves Amdt 1 1 2 Nominal size (DN) Leakage rate mL/min 40 50 80 100 150 200 250 300 350 400 450 500 6
39、00 1,0 1,0 1,5 1,5 2,0 2,5 3,0 3,5 4,0 5,0 5,5 6,0 7,0 Table 2 Maximum permissible leakage rate for resilient seated check valves Amdt 1 1 2 3 Leakage rate Nominal size (DN) Water mL/min Air bubbles per minute 40 50 80 100 150 200 0,30 0,45 0,90 1,70 4,00 6,75 2 3 6 11 27 45 Larger sizes As agreed u
40、pon 4.3.5 Castings with defects 4.3.5.1 Before undergoing the tests referred to in 4.3.4, castings shall be inspected visually for absence of unacceptable defects. A suitable level of acceptability for each specified type of defect shall be agreed upon a) by verbal description of the permissible def
41、ects, their size and their concentration, or b) by reference to an acceptable “first-off“ casting held in safekeeping, or c) by reference to a series of samples showing acceptable and unacceptable defects, or SANS 1551-1:2008 Edition 1.2 8 d) with the aid of reference photographs of acceptable casti
42、ngs, analogous to the method of ASTM A 802/A802M for steel castings. 4.3.5.2 Castings that are unacceptable in terms of this part of SANS 1551 shall not be repaired in any manner. NOTE The types of defect provided for in ASTM A 802/A802M are as follows: A Surface texture; B Non-metallic inclusions;
43、C Gas porosity; D Solidification discontinuities; E Sand expansion discontinuities; F Metal inserts; G Thermally cut surfaces; and H Mechanically prepared surfaces. 4.4 End faces 4.4.1 Flange facing Body end faces shall be fully machined, shall be free from blow-holes, burrs and sharp edges and shal
44、l be finished in accordance with the requirements for joint surfaces as given in SANS 1123. 4.4.2 Parallelism Body end faces shall be normal (to within the lesser of 0,5 or 3 mm) to the centreline of the bore of the valve and, in addition, the faces shall be parallel to each other to within the less
45、er of 0,5 or 3 mm. 4.5 Finish 4.5.1 All cast parts shall have a neat and acceptable appearance and shall be clean, free from blow-holes, sand, buckles, warps or any other defect that impairs the appearance or could impair the strength of the part. 4.5.2 Machined surfaces shall be free from burrs and
46、 sharp edges. 4.5.3 Check valves shall, after having been hydraulically tested, be thoroughly cleaned and then coated, if so required, in a manner as agreed upon. SANS 1551-1:2008 Edition 1.2 9 Table 3(a) Materials for check valves with stainless steel trim 1 2 3 4 5 6 7 Compo-nent Material (see 4.2
47、) Standard Grade or alloy designation Alternative material (see 4.2) Standard Grade or alloy designation Materials other than trim materials Body cover BS EN 1561 220 BS EN 1563 600/3 500/7 420/12 Door Cast iron SANS 1034 250 Spheroidal graphite iron SANS 936 SG 38 Bolting Carbon steel SANS 1700 SAN
48、S 1700 Trim materials Door seat rings and body face rings Stainless steel EN 10090 304S15 Stainless steel EN 10090 316S15 410S21 302S25 431S29 Hinge pin Stainless steel EN 10090 304S15 Stainless steel EN 10090 316S15 410S21 302S25 431S29 Amdt 1; amdt 2 SANS 1551-1:2008 Edition 1.2 10 Table 3(b) Mate
49、rials for check valves with copper alloy trim 1 2 3 4 5 6 7 Compo-nent Material (see 4.2) Standard Grade or alloy designation Alternative material (see 4.2) Standard Grade or alloy designation Materials other than trim materials Body cover BS EN 1561 220 BS EN 1563 600/3 500/7 420/12 Door Cast iron SANS 1034 250 Spheroidal graphite iron SANS 936 SG 38 Bolting Carbon steel SANS 1700 SANS 1700 Trim materials Door seat rings and body face rings Gun metal BS EN 1982 LG2 Aluminium bronze BS EN 1982 AB1 AB2 Aluminium bronz
