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.