As a leading international valve supplier, we stock a wide range of manual knife gate valves and pneumatic knife gate valves for isolation duties. All of our knife gate valves are manufactured in cast iron or stainless steel and will suit PN10, PN16 and ANSI and are suitable for systems with suspended solids, fibrous materials and viscous fluids, such as wastewater, slurry, pulp, paper and food processing.
We offer hand wheel, lever or actuated operation and can supply additional equipment such as side protection plates, hydraulic double acting actuators or double acting pneumatic actuators to complete your unit.
Knife gate valves are isolation valves that use a sharp knife edge to stop flow through a pipeline and cut through any materials that might prevent proper valve sealing.
Knife Gate Valve FAQs
What is a knife gate valve?
A knife gate valve is an isolation valve that allows or stops flow through a pipeline - they feature a sharp (knife) edge that cuts through suspended and fibrous solids or viscous fluids that would otherwise hinder the valve's sealing performance.
How do you properly install and maintain a knife gate valve?
Knife gate valves are designed to be installed between suitably pressure rated flanges, where they will offer many years of reliable isolation services. To get the best from your knife gate valve it should complete at least one cycle annually and be visually inspected for media leaks.
How do you choose a knife gate valve?
Knife gate valves are available in different construction materials, sizes, pressure ratings, actuation methods and more.
To find the most effective knife gate valve model for your application, consider the characteristics of the media in the system, the pressure that will be generated by the flowing media and how often the knife gate valve will need to be opened and closed.
How are knife gate valves operated?
We offer manually and pneumatically actuated knife gate valves.
Our manual knife gate valves are opened and closed via turning a handwheel attached to a rising or non-rising stem, whereas our pneumatic knife gate valves have double-acting pneumatic cylinders that can be operated via a handwheel or remote control system.
What are the main components of a knife gate valve?
Knife gate valves are comprised of several main parts, the main components are:
Body – The main outer structure that contains and supports the internal components.
Plate – Also known as the gate or blade, the movable part of the valve that controls the flow of media.
Seat (seal) – Where the gate makes contact to form a seal when the valve is closed, preventing the passage or leakage of any media.
Stem – Connects the actuator (if present) to the plate, transmitting the force from the actuator to move the gate and open or closing the valve.
Gland follower – A mechanism that compresses packing material around the stem, preventing leakage of fluid along the stem where it passes through the valve body.
Knife Gate Valve Case Studies
Knife Gate Valves for Wastewater Recycling in India
Nehru Gardens in Alwar, India, is fed by a decentralized wastewater treatment system that outputs thousands of litres of recycled wastewater each day – however, the system was underutilised.
T-T Flow supplied pneumatically actuated knife gate valves to enable the wastewater treatment plant to reach its full capacity.
Generating Green Energy at Anaerobic Digestion Plant
As part of a massive renewable energy undertaking by Severn Trent Green Power, our experts supplied over 80 pneumatically actuated knife gate valves to an anaerobic digestion plant in Derbyshire, England.
The valve package included those actuated with double-acting pneumatic cylinders and handwheels, proximity switches and junction boxes for a complete flow control solution.
