Bolted bonnet metal-seated knife gate valves
Features and benefits
No leakage to the exterior through packing chamber (unlike standard knife gate valves)
- Bonneted design: Standard body-bonnet joint with an efficient non-asbestos reinforced fiber or PTFE gasket.
- Long-life leakproof stem seal: Standard packing chamber with 125 RMS wall finish, burnished non-rotating stem and PTFE or graphite packing rings. Many times the cycle life of a standard knife gate valve.
- Virtually no contamination of the environment: No dewatering of stock, unlike standard knife gate valves.
- Easy repacking in-line. (Valve should be de-pressurized when repacking in-line.)
Tighter seats with positive torque closure of knife
- Beveled knife-stem connection locks the knife blade tight against the seat. The seat is sealed by positive torque closure – not media pressure – unlike any other knife gate valve.
- Raised-face seat: A groove around the seat collects particles pushed aside by the knife and prevents clogging. When the valve opens, media pressure cleans the groove.
- Lapped seat ensures tight closure.
Bypass to prevent clogging of bonnet
- Bypass lets pulp circulate inside the bonnet when valve is opened, preventing clogging.
- Lower running torque due to reduced friction: Friction between stem and packing in bolted bonnet knife gate valve is far less than the friction between the blade and the packing in a standard knife gate valve.
- Low-friction, acid-resistant Ni-Resist stem nut:
- Valves can operate with smaller actuators than standard knife gate valves, due to lower running torque.
All cast stainless steel design
- One-piece stainless steel, fully-lugged, cast body is stronger than welded bodies and less subject to distortion due to thermal stress. Posts are stainless steel instead of chrome-plated carbon steel for longer life.
- Designed for vertical or horizontal line operations.
- Standard wafer, TAPPI face-to-face for easy replacement of leaky standard knife gate valves.
- Maintenance and adjustment-free. Long cycle life.
- Suitable for most pulp and paper applications. Can be used throughout the mill as a general-purpose knife gate valve up to 5% pulp consistency.