GATE VALVES

ProMetal provides gate valves from ½” (DN25) and up, in many different designs.

Gate valves are designed to isolation and are for that reason either completely closed or completely opened. Some kind of designs though, like the “V port seat”, is used for smaller regulation tasks where the need for high precision is less important. The valve is often used when a minimal amount of pressure loss and a total flow through are needed.

The operation of a gate valve happens with help from a thread cut mandrel, that, when handled, makes the gate move up and down at the mandrel. This process is the reason a gate valve is also known as a “multi-turn valve”. It is called CTC when the valve closes when the mandrel rotates clockwise. It is called CTO when the valve opens when the mandrel is rotated anticlockwise.

The valves can be used in all kinds of applications both in installations above the ground and in applications under the ground. If it is used in an installation under the ground, it is crucial to find the right valve, or it will result in very high replacement costs.

The disadvantages of the gate valve

The disadvantage of the valve is that it needs relatively much space in the height, but the advantage is that in suffer from very little pressure loss when the valve is open. At the same time it has the advantage of being bi-directional, meaning that the flow can go in both directions.

Gate valves are relative slow opening, and an actuator is often needed for larger valve sizes. The gate valve is known as the one valve design, which is the hardest to repair and maintain while being mounted in the pipeline. It is possible though, and Trillium Flow Technologies (formerly known as Weir Flow Control), are specialized in replacing seats in larger welded gate valves.

Design:

• Parallel slide gate valve, primarily used for steam
• Parallel slide gate valve with V port seat for control purpose
• Uni flow parallel slide gate valve, primarily used for drain functions
• Through conduit gate valve, often used offshore for “pigging” (valves being exposed to dirt)
• Wedge type gate valve (solid, hollow, slap gate, split and flexible wedge gate)
• Non rising stem / rising stem gate valves

Please contact ProMetal A/S for further information about gate valves.