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The disc valve is a valve that has a metal-to-metal sealing surface and works in rotating shearing mode.
It is particularly suitable for on/off and throttling both applications for abrasive media or slurry entrained particles.
The actuator drives the stem to rotate at a certain angle to move the disc in full open, full close and middle positions.
The disc is constantly in contact with the seat through force loaded by coiled springs. These springs allow the disc to move vertically is better to compensate thermal expansion and contraction of the valve components also overcoming the effect of any back pressure for which it was designed and prevents particles from lodging between the sealing surfaces.
Differences between drive forces in the tangential disc and friction forces in the centre disc cause the disc to rotate on its seat as the valve cycles, thereby shearing and wiping away any process mediums that may accumulate.
This rotate helps grinding and polishing of the sealing surface of the valve continuously, which can maintain seat leakage improved in a long term.
EVT PROCESS VALVE (EPV)
Size: DN50-DN450
Pressure: Class150-Class2500
Body Material: Carbon Steel, Stainless Steel and other materials
Actuators: Pneumatic, Hydraulic Cylinder, Hand wheel
• The pneumatic actuator can be equipped with a double acting pneumatic cylinder or a single acting pneumatic cylinder.
• The independent packing gland is fixed with bolts. In such a way, the packing force is distributed more evenly and applied more stably, and the packing gland will not be loosened due to waggling of the stem. The packing is spiral wound Grahite or Teflon with replaced online feature. And Spiral wound gaskets are used for body sealing.
• More packing rings with larger Cross Section ring are used.
• Larger stem is used to increase the output torque of the stem and enhance the stability of the valve switch. The stem is with blow-out proof feature.
• The flow channel can be hardened (optional).
• End to End dimension compiles with ASTM B16.10. Other options are available per customer’s request.
Flange is a standard end connection compiling with ASTM B16.5. Other options are available per customer’s request.
Larger and more distributed body bolting: maintain a better bolting load on body seal.
• Many harden treatments for disc and seat are available. – Tungsten Carbide Clad – Solid Tungsten Carbide – Stellite Overlay
• Designed thickness of valve body is no less than specified data per ASME 816.34, Better erosion resistance.
Seat leakage can meet below specifications by polishing and mate lapping: -MSS-SP61 per ANSI 816.34 -Class VI per FCI 70-2 -API 598
Size: DN15-DN450
Pressure: Class125, Class150, Class300 Body
Material: Carbon Steel, Stainless Steel Actuators: Pneumatic