- Standards:
- Design and Manufacture: ANSIB16.34, API600 API6D, API603,BS1414
- Face to face(end to end): ANSIB16.10, API6D
- Flange connection: 2″~24″to ANSIB16.5,
- 26″~36″to MSS-SP-44 to API605 on Request
- Test and inspection: API598,API6D
- Butt welded end: ANSIB16.5
Flexible Wedge Gate Valve
Description
The flexible wedge is a one-piece solid disk with a cut around the perimeter. These cuts vary in size, shape, and depth. A shallow, narrow cut on wedge perimeter gives less flexibility but retains strength. A cast-in recess or deeper and wider cut on wedge perimeter gives more flexibility but compromises the strength.
This design improves seat alignment and offers better leak tightness. It also improved performance in situations where thermal binding possible. Flexible wedges Gate valves are used in steam systems.
Thermal expansion of steam line sometime causes distortion of valve bodies which may lead to thermal blinding. The flexible gate allows the gate to flex as the valve seat compresses due to thermal expansion of steam pipeline and prevent thermal blinding.
The disadvantage of flexible gates is that line fluid tends to collect in the disk. These may result in corrosion and ultimately weaken the disk.
Material
Body | ASTM A 216 WCB / A 217 WC6 / A 217 WC9 / A 217 C5 / A 217 C12 / A 351 CF8 / A 351 CF8M / A 351 CF3 / A 351 CF3M / A 352 LCB |
Bonnet | ASTM A 216 WCB / A 217 WC6 / A 217 WC9 / A 217 C5 / A 217 C12 / A 351 CF8 / A 351 CF8M / A 351 CF3 / A 351 CF3M / A 352 LCB |
Wedge | ASTM A 216 WCB / A 217 WC6 / A 217 WC9 / A 217 C5 / A 217 C12 / A 351 CF8 / A 351 CF8M / A 351 CF3 / A 351 CF3M / A 352 LCB |
Stem | ASTM A 276 410 / A 276 304 / A 276 304L / A 276 316L |
Seat Rings | ASTM A 216 WCB / A 217 WC6 / A 217 WC9 / A 217 C5 / A 217 C12 / A 351 CF8 / A 351 CF8M / A 351 CF3 / A 351 CF3M / A 352 LCB |
Back Seat Bushing | ASTM A 276 410 / A 276 304 / A 276 304L / A 276 316L |
Gland | ASTM A 276 410 / A 276 304 / A 276 304L / A 276 316L |
Gland Flange | Carbon Steel / Stainless Steel |
Stem Nut | ASTM A 439 Gr.D2 / Al. Bronze |
Lock Nut | Carbon Steel / SS 304 |
Gland Packing | Graphite Asbestos / Graphoil / PTFE |
Bonnet Gasket | Corrugated Soft Iron / Corrugated SS / Spiral Wound SS 304 with Asbestos or Graphoil / Octagonal Ring |
Gland Eye – Bolt & Nut | Carbon Steel / Stainless Steel |
Cross Bolts & Nuts | Carbon Steel / Stainless Steel |
Hand Wheel | Carbon Steel |
Hand Wheel Nut | Carbon Steel |
Grease Nipple | Carbon Steel |
Grub Screw | Carbon Steel |
Studs / Bolts | ASTM A 193 B7 / A 193 B7M / A 193 BBM / A 320 L7 |
Nut | ASTM A 194 2H / A 194 8 / A 194 8M / A 194 4 / 7 |