Standard No.:	GB/T 24925-2019
English Name:	Low temperature valve—Technical specifications
Chinese Name:	低温阀门 技术条件
Chinese Classification:	J16    Valve
Professional Classification:	GB    National Standard
ICS Classification:	23.060.99 23.060.99    Other valves 23.060.99
Issued by:	SAMR and SAC
Issued on:	2019-10-18
Implemented on:	2020-5-1
Status:	valid
Superseding:	GB/T 24925-2010 Cryogenic valve technical specifications
Language:	English
File Format:	PDF
Word Count:	14500 words
Price(USD):	380.0
Delivery:	via email in 1 business day

Low temperature valve - Technical specifications 1 Scope This standard specifies the structural types, technical requirements, test methods, inspection rules, marking, painting, packaging, transportation and storage of low temperature valve (hereinafter referred to as “valve”). This standard is applicable to the flanged, wafer and welded low-temperature gate valves, stop valves, check valves, ball valves and butterfly valves with nominal pressures of PN16~PN400 and nominal dimension of DN15~DN1,200, or those with pressure class of 150~2,500, nominal dimension of NPS 1/2~NPS 48 and medium temperature of -196℃~-29℃. This standard may be used for reference for other low temperature valves. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 229 Metallic materials - Charpy pendulum impact test method GB/T 9113 Integral steel pipe flanges GB/T 12220 Industrial valves - Marking GB/T 12221 Metal calves - Face to face, end to end, center to face and center to end dimensions GB/T 12222 Multi-turn valve actuator attachments GB/T 12223 Part-turn valve actuator attachments GB/T 12224 General requirements for industrial steel valves GB/T 12225 General purpose industrial valves - Specification of copper alloy castings GB/T 12234 Bolted bonnet steel gate valves for petroleum and natural gas industries GB/T 12235 Steel globe valves and lift check valve for petroleum petrochemical and allied industries GB/T 12236 Steel swing check valve for petroleum petrochemical and allied industries GB/T 12237 Steel ball valves for petroleum petrochemical and allied industries GB/T 12238 Flanged and wafer resilient seal butterfly valves GB/T 13402 Large diameter steel pipe flanges GB/T 21387 Axial flow check valve GB/T 22652 Overlaying-welding procedure qualification for valves sealing face GB/T 26479 Fire test for soft-seated quarter-turn valves GB/T 26480 Valve inspection and testing GB/T 26482 Fire type-testing requirement for check valves GB/T 26640 Specification for minimal thickness of the shell of valves GB/T 28776 Steel gate, globe and check valve for the petroleum and natural gas industries (for sizes DN100 and smaller) JB/T 6438 Technical requirements for plasma arc overlaying welding for valve sealing surface JB/T 6439-2008 Methods of magnetic examination for valves JB/T 6440-2008 Methods of radiographic examination for steel castings valves JB/T 6903-2008 Methods for ultrasonic examination of steel forgings for valves JB/T 7248 Technical specification for low temperature service steel casting for valves JB/T 7746 Compact steel valves JB/T 7927 Valve cast steel visual quality requirements JB/T 7928 Industrial valves - Delivery specification JB/T 8527 Metallic sealing butterfly valve JB/T 12003 Specification for valve cryogenic test rig JB/T 12622 Liquefied natural gas valves - Performance testing NB/T 47009 Low alloy steel forgings for low temperature pressure equipment NB/T 47010 Stainless and heat-resisting steel forgings for pressure equipments NB/T 47013.2-2015 Nondestructive testing of pressure equipment - Part 2: Radiographic testing NB/T 47013.4 Nondestructive testing of pressure equipments - Part 4: Magnetic particle testing NB/T 47013.5-2015 Nondestructive testing of pressure equipments - Part 5: Penetrant testing NB/T 47014 Welding procedure qualification for pressure equipment 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 bonnet extension part between the top of the bonnet bracket and the bottom of the bonnet packing box part between the top of the lower bushing of the bonnet and the bottom of the packing box for the valve with lifting stem part between the top of the lower bonnet bearing and the bottom of the packing box for quarter-turn valve

Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Structural types 5 Technical requirements 5.1 General requirements 5.2 Performance 5.3 Valve body 5.4 Bonnet 5.5 Valve stem 5.6 Opening and closing parts and valve seats 5.7 Packing and packing box 5.8 Middle flange seal 5.9 Operation 5.10 Materials 5.11 Appearance quality of steel casting 5.12 Defect disposal 5.13 Non-destructive testing 6 Test methods 6.1 Marking inspection 6.2 Appearance quality of steel castings 6.3 Dimension inspection 6.4 Chemical composition 6.5 Mechanical properties 6.6 Cold test 6.7 Low temperature test 6.8 Low-temperature cycle life test 6.9 Non-destructive testing 6.10 Anti-static test 7 Inspection rules 7.1 Inspection items 7.2 End-of-manufacturing inspection 7.3 Type test 8 Marking 9 Painting, packaging, transportation and storage Annex A (Informative) Recommended material of low temperature valve Annex B (Informative) Schematic diagram for internal cooling cycle