Category
Valves
Subcategory
Check Valve
Applicable standards
5
Issuing bodies
3
Description
Non-return valve — swing, wafer, lift, tilting disc, dual-plate types.
Applicable Standards (5)
API — 3 standards
API 594
Check Valves: Flanged, Lug, Wafer and Butt-welding
Wafer/lug/flanged/butt-weld check valves Class 125 through 2500.
Key requirements (7)
- Check valves — wafer, lug, double-flanged.
- Sizes: NPS 2 to 48; classes 125, 150, 250, 300, 600.
- Disk types: dual-plate (most common), tilting disc, swing.
- Hydrotest per API 598 — shell & seat.
- Disk closure spring: prevents slamming on flow reversal.
- Wafer style: bolted between flanges, lighter than flanged check.
- Selection: cracking pressure, allowable backpressure, fluid service.
API 602
Gate, Globe, and Check Valves for Sizes DN 100 (NPS 4) and Smaller for the Petroleum and Natural Gas Industries
Compact (small-bore) carbon steel valves for petroleum, petrochemical and gas service.
Key requirements (5)
- Gate, globe, check valves NPS ≤ 4 (DN 100), Class 800–4500 (compact body).
- For instrument tubing, isolation, drains, vents in process plant.
- Forged body construction.
- Bolt-bonnet, welded-bonnet or pressure-sealed bonnet.
- Hydrotest per API 598.
API 6D / ISO 14313
Pipeline and Piping Valves
Ball, check, gate, and plug valves for pipeline service.
Key requirements (7)
- Pipeline valves — ball, gate, check, plug for liquid and gas pipelines.
- Pressure classes: ASME B16.34 (150–2500) plus API-specific (10000 / 15000 psi).
- Full-bore (full opening) — passes pipeline pig with min restriction.
- Fire-safe per API 6FA / ISO 10497.
- Anti-static device required (ball/stem ground continuity).
- Double Block & Bleed (DBB) and Double Isolation & Bleed (DIB) configurations.
- Cavity over-pressure relief required (self-relieving seat or cavity vent).
ASME — 1 standard
ASME B16.34
Valves — Flanged, Threaded, and Welding End
Pressure-temperature ratings, dimensions, materials, NDE, marking and testing for valves.
Key requirements (7)
- Pressure–temperature ratings for valves (steel).
- Pressure classes: 150, 300, 400, 600, 900, 1500, 2500, 4500.
- Body wall thickness: t = (P·d)/(2·S·E − 1.2·P) + c, plus tabulated minimums.
- Hydrotest: shell at 1.5 × Class 100 °F rating; seat at 1.1 × Class 100 °F rating.
- Special class allows 25% above standard rating with stricter NDE (radiography + hardness).
- Materials per ASME II Part D allowable stress.
- End connections: threaded, flanged, butt-weld, socket-weld.
BIS — 1 standard
IS 5312
Swing Check Type Reflux (Non-Return) Valves
Indian standard for swing check (non-return) valves.