What is a gate valve and where is it used? Learn more about types of gate valves, working principle, design options and applications in the water supply system.
A gate valve has a simple design and can be applied in many low pressure-drop services, which makes it one of the most common valves in use today. Gate valves are designed as full-port valves. This means that the valve port is of the same size as the inner diameter of the connecting pipe. Full-bore gate valve passes the fluid flow without any obstructions to a flow and do not cause a pressure drop in a pipeline. This also allows to clean the pipe using a cleaning pig.
A resilient seated gate valve with a non-rising spindle consists of the following parts:
The body is the largest element of the gate valve. Since the spindle remains in the valve body during rotation, it allows an economical bonnet construction. The valve bonnet itself is joined to the body with bolts, which allows cleaning and maintenance. As the gate valve closes, the wedge travels down until it presses the valve seat, which would mean a complete shutoff. During the opening the wedge slides towards the upper part of the valve body.
A wedge gate valve construction did not alter a lot for the last 100 years. However, the design of some elements of the gate valve has undergone some modifications. Most of the changes are aimed at increasing the service life of the gate valve, improving the sealing characteristics, using superior quality materials and epoxy coatings for a better corrosion protection. At the same time, the modern gate valve body has a compact sleek design, allowing installations in limited space conditions. There are already 7 generations of Hawle gate valve models which have been developed in the last 70 years.