COMMON VALVE TYPES
Knife-Gate Valves
The families that appear on first RFQs and Chinese export quotes. Shared names are not interchangeable designs.
Choosing Knife-Gate Valves
A knife-gate valve moves a thin gate through the flow passage. It is often considered for solids-bearing duties, but unidirectional, bidirectional and sleeve-based designs differ. Fluid behavior, pressure direction and the seating arrangement must be identified before comparing quotations.
What to include in the RFQ
- Describe solids concentration, particle size, fibers and whether material settles while the valve is idle.
- State pressure direction, required seat tightness and any reverse-pressure condition.
- Request gate, seat or sleeve materials and the replacement procedure for wearing components.
- Confirm actuator thrust, closure conditions and permission for end-of-line installation.
Selection scenario
On a sludge isolation point that operates infrequently, tell bidders about settled material and the maximum closing differential. Review maintenance access and the seat arrangement rather than choosing solely on nominal bore.
Common selection mismatch
Knife gate is not a universal bidirectional or throttling specification. Require written confirmation for the exact design and duty.