A check valve or non-return valve which normally allows to flow through it in only one direction.
Check valves are two-port valves, means they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Although they are available in a wide range of sizes and costs, Check valves work automatically and most are not controlled An important concept in check valves is the cracking pressure which is the minimum upstream pressure at which the valve will operate.
A swing check valve or tilting disc check valve is check valve in which the disc, the movable part to block the flow, swings on a hinge or trunnion, either onto the seat to block reverse flow or off the seat to allow forward flow.
A lift-check valve is a check valve in which the disc, can be lifted up off its seat by higher pressure of inlet or upstream fluid to allow flow to the outlet or downstream side. A guide keeps motion of the disc on a vertical line, so the valve can later reseat properly. When the pressure is no longer higher, gravity or higher downstream pressure will cause the disc to lower onto its seat, shutting the valve to stop reverse flow.
SIZE AND RATINGS | |
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Size 800# | 15 to 50 m.m. |
1500# | 15 to 40 m.m. |
2500# | 15 to 25 m.m. |
MANUFACTURING STANDARDS | |
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MFG DESIGN | BS 5352/API 602 |
Face TO Face DESIGN | MFG |
End connection | Ssrewed End/soket Weld End/ Butt Weld end |
MATERIAL | |||
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1 | BODY&COVER | ASTM A 105/F11/F22/LF2/F304/F304L/F316/F316L/F51/F53/F55/F347/F321/INCONEL 625/MONEL 400/HASTELLOY C276/ALLOY 20 | |
2 | DISC | ASTM A 217 Gr CA15/ASTM A 351 Gr CF8/CF8M/CF3/CF3M | |
3 | seat ring | ASTM A 479 TYPE SS410,SS304,SS316,SS304L,SS316L/FS A 182 F304/F316/F304L/F316L | |
4 | Gasket | /304/SS316 Sairal Wound Grafite Filer | |
5 | BODY&COVER JOINT BOLT | ASTM A 193 Gr B5/B6/B7/B7M/B16/B8/B8A/B8C/B8M/B8MN |
MATERIAL | |||
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1 | BODY&COVER | ASTM A 216 Gr WCB/WCA/WCC/ASTM A 217 Gr WC1/WC6/WC9/C5/C12A/CA15/ASTM A 351 Gr CF8/CF8M/CF3/CF3M/CF8C/CF10/CK20/HK30/ASTM A 352 Gr LCB/LCC/LCA/CA6NM/ASTM B148 C95500/C95800/C95400 | |
2 | DISC | 13%CR/STELLITED/ASTM A 351 Gr CF8/CF8M/CF3/CF3M/ASTM B148/C95500/95800/95400 | |
3 | LEVER | ASTM A 216 Gr WCB/WCA/WCC/ASTM A 217 Gr WC1/WC6/WC9/C5/C12A/CA15/ASTM A 351 Gr CF8/CF8M/CF3/CF3M/CF8C/CF10/CK20/HK30/ASTM A 352 Gr LCB/LCC/LCA/CA6NM/ASTM B148 C95500/C95800/C95400 | |
4 | seat ring | 13%CR/STELLITED/ASTM A 351 Gr CF8/CF8M/CF3/CF3M/ASTM B148/C95500/95800/95400 | |
5 | GLAND BUSH | SS316 Sairal Wound Grafite Filer | |
6 | BODY&COVER JOINT STUD | ASTM A 193 Gr B5/B6/B7/B7M/B16/B8/B8A/B8C/B8M/B8MN | |
7 | BODY&COVER JOINT NUT | ASTM A 194 Gr 2H/2HM/6F/7M/8/8A/8CA/8M/8MA/8F/8N/8MNA/ |