Knife Edge Gate Valve

Knife Gate Valve mostly uses to handle powder; high viscous or slurry type thick media service to cut throughout and close the valve.

Zeel engineers is Knife Gate Valve manufacturers and exporters in Unidirectional and Bi-Directional type, Rising Stem and Non-Rising Stem with Metal to Metal Seat & Soft Seat which mostly use in service of Isolation and On-Off service.

The valve sliding plate (gate) has knife edge, so it is called Knife Gate Valve or Knife Edge Gate Valve which both are same. Previously it was mostly use in service of Powder, Slurry, Pulp and Paper Mill now it use in many more industrial applications. Some user also asks for Slide Gate Valve in place of Knife Edge Gate Valve.

Zeel engineers and leading manufacturer and exporter of valves to Dubai, Kuwait, Kingdom of Saudi Arabia, Jeddah, Jubail, Malaysia, Thailand, Singapore, Australia, Brazil, Italy, Romania, Azerbaijan, Sharjaha, Abu Dhabi, United Arab Emirates, Egypt, Turkey, Sri Lanka, Yemen, Pakistan, Bahrain, Indonesia, Zambia, Uganda, Netherlands, Philippines, Vietnam, Dominican Republic, Oman, West Africa, Finland and Jordan.

Knife Edge Gate Valve has very simple construction and assembly is with very few parts like Body, Knife Gate, Seat, Gland Flange, Gland Packing and Yoke – Bonnet Assembly.

Each knife gate valve body design is single piece casted heavy duty construction, slide gate plate grinded with lapped and seat integral with body or renewable type as customer request.

Knife Edge Gate Valve Material of Construction

• Body Design – Unidirectional and Bi-Directional (flow can be from either or side)
• Body Construction – Single Piece Casted, Rugged, Heavy Duty
•  Knife Gate – Knife Gate Plate supply in Stainless Steel (S.S.) 304/316/304L/316L, other special grade on request. Knife Gate both side fully machined, grinded, buffed and lapped at seat contact side with beveled edges to extend life of Gland and Seat.
• Stem – Single Piece from heavy duty round bar with quality square thread and brass or gun metal stem nut to extend life of stem.
• Seat –

1. Integral Metal to Metal seat as per MSS SP-81 Standard
2. Renewable Type Seat: Elastomer, Rubber Seat (NBR, EPDM, Nitrile, Neoprene, Viton, Silicon Rubber O-Ring)
3. Renewable Type Seat: PTFE (Teflon) Soft Seat
4. Deflection cone with Stellite Hard Face – F6

•  Port Opening – Full Round Port / V – Notch Type

Advantages of Knife Edge Gate Valve

• Low cost
• Light weight
•  Fast production
•  Easy to operate
• Easy Installation
• Easy to repair-replace
• Best performance in viscous, slurry, pulp and powder application
• Wide choice of operation
• Wide choice body, seat and gate materials
• Wafer, Lug, Flanged End Connection option

Design and Testing of Knife Edge Gate Valve

• Body Type : Single Piece, Wafer – Full Lug Type, Flangeless, Sandwich Type (Suitable to mount between two flanges)
• Design : MSS SP-81 (Body Hydraulic Test at Rated Pressure 150 psig x 1.5 Times = 225 psig)
• Seat : MSS SP-81 (Seat Hydraulic Test at Rated Pressure 150 psig x 1.1 Times = 165 psig)
• Metal to Metal Seated Knife Gate Valve Seat Leakage : Allowable seat leakage rate for metal to metal seated knife gate valve of 40 cc per inch of diameter, per minute at 40 psi pressure. On a 12″ valve this would be equal to 40 times 12, or 480 cc per minute at 40 psi. Maximum allowable leakage of 2.73 LTR/MIN when tested with water at 40 psi applies in normal flow direction
• Soft Seated Knife Edge Gate Valve Seat Leakage : No visible leakage when tested with water at 40 psi.
• Face to Face Distance : MSS SP-81
• Flange Drilling : Raised Face Body, As Per ASME B 16.5, Class 150
  Throughout elliptical hole in all lugs and Tapped hole in body chest area.
• Size Range : DN50 (2”) To DN900 (36”)
• Pressure Rating : Up to DN600 (24”) 150psi (10bar), DN750-900(30-36”) 100psi (7bar)