What is the difference between a knife gate valve and a gate valve?

Knife gate valves are primarily designed for switching and isolation services in systems with high suspended solids content. Knife gate valves are particularly suitable for handling slurries, viscous, corrosive and abrasive media. These valves have minimal pressure drop in the fully open position, they are easy to actuate, relatively lightweight and cost effective.

What is the difference between a knife gate valve and a gate valve?

Both wedge gate valves and knife gate valves are primarily designed for on-off services where the valve is fully open or fully closed. These two methods are not recommended for regulating flow because of the vibration that occurs when the fluid pushes against a partially closed gate, and cavitation can eventually damage the seat and body. Additionally, both valves are designed to open and close slowly to reduce the risk of water hammer.

Where are knife gate valves used?

Knife gate valves are designed to work in some of the harshest environments, often with sharp blades to cut through heavy liquids.

They are especially useful in wastewater applications where corrosion is an important issue. Therefore, in addition to valve designs optimized for slurry media, it is better to use knives made of acid-resistant stainless steel, as this will reduce damage caused by corrosion, thus reducing the frequency of maintenance and even replacement.

Knife gate valves should only be used in applications requiring a fully open or fully closed position and should not be used to regulate flow unless they are designed for this purpose. Whenever fluid is forced against a partially closed gate, vibrations are created that gradually erode the disc and seat. Additionally, knife gate valves are designed to open and close slowly to prevent the effects of water hammer.

How does a knife gate valve work?

Knife gate valves work by allowing thick media to flow easily through soft seals without disturbance. They work by shredding the media as it passes through the valve. Today, Knife Gate Valves are used in numerous processing plants around the world and come in very large sizes. This makes it easier for the valve to handle dense media flows including grease, oil, slurries, wastewater and pulp. Therefore, the Knife Gate Valve has a low pressure limit and is designed to hold the blade in a soft seal without interruption.

Why use a knife gate valve?

The main reasons for choosing knife gate valves are that they are cost-effective, easy to actuate, and lightweight. They are also very effective in many industries and processes. Knife gate valves are designed with sharp edges to cut through the pulp and seal. With this useful attribute, knife gate valves become invaluable in applications involving slurries, viscous fluids, and other systems with shock problems.