Vārsti

Design Standard for valves

American Standard

• ASME: American Society of Mechanical Engineers;
• ANSI: American National Standards Institute;
• API: American Petroleum Institute;
• MSS SP: American Society for standardization of valve and fitting manufacturers;
• British Standard: BS;
• Japanese industrial standard: JIS/JPI;
• German national standard: DIN;
• French national standard: NF.

General valve standard: ASME B16.34 flanged end, butt welded end and threaded end valves.
Standard for gate valves:

• API 600/ISO 10434: bolted steel gate valves for petroleum and natural gas;
• BS 1414: steel gate valves for petroleum, petrochemical and refining industries;
• API 603: 150Lb corrosion resistant flange end cast gate valve;
• GB/T 12234: flanged and butt welded steel gate valves;
• DIN 3352: gate valves;
• Shell SPE 77/103: steel gate valve as per ISO10434.

Standard of stop valve:

• BS 1873: Steel globe and check valves;
• GB/T 12235: flanged and butt welded steel globe and check valves;
• DIN 3356: stop valves;
• Shell SPE 77/103: steel stop valve as per BS1873.
• Standard for check valves:
• BS 1868: steel check valves;
• API 594: wafer and double flange check valves;
• GB/T 12236: steel swing check valve;
• Shell SPE 77/104: steel check valve as per BS1868.

Standard for ball valves:

• API 6D/ISO 14313: pipeline valves;
• API 608: flanged, threaded and butt welded end steel ball valves;
• ISO 17292: steel ball valves for petroleum, petrochemical and refining industries;
• BS 5351: steel ball valves;
• GB/T 12237: flanged and butt welded steel ball valves;
• DIN 3357: ball valves;
• Shell SPE 77/100: ball valve as per BS5351;
• Shell SPE 77/130: flange end and butt welding end ball valves according to ISO14313.

Standard of butterfly valve:

• API 609: wafer, lug and double flange butterfly valves;
• MSS sp-67: butterfly valve;
• MSS sp-68: high pressure eccentric butterfly valve;
• ISO 17292: steel ball valves for petroleum, petrochemical and refining industries;
• GB/T 12238: flanged and wafer connected butterfly valves;
• JB/T 8527: metal seal butterfly valve;
• Shell SPE 77/106: soft seal butterfly valve as per api608/en593/MSS sp67;
• Shell SPE 77/134: eccentric butterfly valve as per api608/en593/MSS sp67/68.

Standard for forged steel valves:

• API 602: flanged, threaded, welded and extended body connection end compact gate valves;
• BS 5352/ISO1576: steel gate, globe and check valves 150 mm and below;
• Shell SPE 77/101: steel gate valve, globe valve and check valve according to ISO15761.
• Standard for cryogenic valves:
• BS 6364: low temperature valves;
• Shell SPE 77/200: Valves below – 50 ℃;
• Shell SPE 77/209:0 – – 50 ℃ valve.

Structure comparison of API, DIN, BS and GB:

• API 600, BS1414, BS1873, BS1868 and BS5351 have the most detailed regulations on the structure of valves;
• The structure is not specified in DIN gate valve standard en1984;
• The new version of GB/t12234 is based on the equivalent adoption of API600 standard.

Common connection end forms of valves

• FF — flat face plane flange connection (150Lb common);
• RF – raised face flange connection;
• RTJ – ring joint tenon and groove connection (trapezoidal groove);
• SW — socket welding socket connection;
• NPT — NPT threaded connection;
• Wafer – wafer connection;
• BW long – butt welding end long connection;
• BW short – butt welding end short connection.

DIN standard now adopts en standard structure length
The structural length of EN 558-1 PN flange connected valve (instead of DIN 3202), en 558-2 class flange connected valve (instead of BS2080), en 12982 butt welding end valve (instead of DIN 3202). The structural length of DIN standard includes that of API valve, which is basically consistent with that of GB.
The structural length of EN 558-2 class flanged valves is consistent with ASME B16.10. Most DIN valve users are used to using the F series structural length value in DIN3202.
For example:

• Gate valves: PN16-25—- F5 series  PN40-100—-F7 series；
• Globe vārsti: PN10-40—-F1 series  PN63-160—-F2 series；
• Check vārsti: PN10-40—-F1 series  PN63-160—-F2 series；
• Ball vārsti:   PN10-40 DN10-100—-F4 seriesDN125-300—-F5 series.

Standard for connecting end of valve

• ASME B16.10: structural length of valves;
• ASME B16.5: steel flanges and flanged fittings;
• ASME b16.47: large diameter steel flanges;
• MSS SP-44: steel pipeline flange;
• API 605: compact flange;
• ASME B16.25: butt weld ends;
• ASME B16.11: Forged Fittings with socket and threaded ends;
• ASME B36.10: Welded and seamless steel tubes.

Comparison of flanges:
The old DIN standard flange adopts din2501 standard (PN flange), and the new DIN standard adopts EN1092-1 PN flange, but class flange can also be included.
DIN2501 flange is basically consistent with GB flange and Hg European system flange.
DN15 – 50 flanges with different pressures PN10 – 40 are the same
BS 1560 class flange is adopted as BS standard, which is consistent with ASME B16.5 flange, or BS 4504 PN flange can be adopted.
API standard generally adopts RF and RTJ flanges; RF flange is adopted when DIN standard and GB pressure are < PN40, and concave flange is generally adopted when pressure is ≥ PN40.

Seal material

Packing:

• Formed graphite ring: – 250 – 650 ℃;
• Flexible graphite with stainless steel wire: – 250 – 650 ℃;
• Tetrafluoroethylene impregnated graphite: – 200 – 280 ℃;
• Low leakage graphite combined packing: – 250 – 650 ℃;
• PTFE: -200~200℃.

Middle cavity gasket:

• PTFE plate
• Graphite plate
• Strong graphite pad
• Toothed pad
• Stainless steel winding pad with graphite
• Including PTFE stainless steel winding pad
• RTJ metal pad
• Pressure seal metal seal ring

O-ring:

• NBR: -30~121℃；
• EPDM: -45~120℃；
• VITON A: -30~204℃；
• VITON B: -30~204℃；
• VITON AED: -30~204℃；
• HNBR: -30~180℃.

Soft seal seat:

• PTFE: -200 – 200℃；
• PCTFE: -250 – 150℃；
• NYLON 1010: –  20℃；
• NYLON PA12: -50  – 120℃；
• DEVLON V: -100 – 150℃；
• PEEK: -100 – 260℃；
• Para polyphenylene: – 400 ℃.

Inspection standard for valves

• API 598: Valve Inspection and test;
• ISO 5208: pressure testing of industrial valves;
• BS EN 12266-1: pressure test for industrial valves instead of BS6755-1;
• JB/T 9092: Inspection and test of valves;
• Shell spe77/302: general valve material, inspection and certificate requirements;
• Shell spe77/303: material, inspection and certificate requirements for valves under special working conditions.

Comparison table of common valve materials (forgings and castings): (comparison between American Standard and national standard)

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