VAAS - Valves with a Leading Edge

These are specially designed uni-directional knife gate valves for use in pulverized coal mills in coal-fired thermal power plants. Design features a full port bore which is typically hardfaced to stand the highly erosive flow of pneumatically conveyed fine coal to the boiler. As these are used in the coal mills, the valves are designed to comply to the requirements of the NFPA-85 (2001) standard. The valve is a flanged design and the fange drilling conforms to the requirements of major coal mill manufacturers such as BHEL, Mitsui Babcock, Foster Wheeler and others. VAAS offers these valves in most of the sizes these valves are requested for- 300mm, 400mm, 650mm being very common sizes.

Type	Wafer, flanged, uni-directional knife gate valve; rising stem handwheel; specially designed for Coal Mill Isolation
Typical Application	Mill Isolation in coal fired power plants
Sizes available	300,400,450,500,550,600,650mm (12,16,18,20,22,24 and 16inch) ; full port
Pressure rating	Designed to meet NEPA-85(2001) requirements
Face-to face	Complies with MSS SP-81 (upto 900mm (36”) size)
Drilling	Meets major mill OEM standards (Mitsubishi Babcock,Foster Wheeler, BHEL); also ANSI 150lb and others on request
Material availability	standard; others on request
Body	Cast steel, typically offered with hardfaced flow bore
Gate	304 steel; optional hardfacing
Packing	PTFE syntex fiber standard; others on request
Seat/Leakage	Metal-to-metal – As per ANSI Class IV
Superstructure	Steel, epoxy painted
Handwheel	Cast iron, epoxy painted
Pneumatic actuators	Suitable model is VAAS CCGCx & CCMCx Series