Everything you need to know about gate valves

Do you know what exactly a gate valve is? If not, let me tell you. It’s a type of valve that is used as a wedge type disk or a gate. Gate valves manufacturers have designed it in a certain matter that it moves in a perpendicular direction to start, to stop or to flow the fluid that happens in the piping process.

It’s one of the most common types of valve process plants. These valves are either available in fully closed or fully opened positions. In a fully open gate valve, the disk of a gate valve is completely removed from the entire flow. However, in a fully closed gate valve, there is a requirement of surface contact between the seats and the disks.

It has to be ensured, that gate valves are not used for throttling or regulation of flow due to no accuracy of control. If the open valve has high velocity available, it might cause seating surfaces and disc erosion that further causes noise and vibration.

The parts of the gate valve include body, bonnet, solid wedge, body seats, stem, back seat, gland follower, gland flange, stem nut, yoke nut, handwheel, hand wheel nut, stud bolts, nuts, stud bolts, nuts, bonnet gasket, lubricator, and packing.

What are the advantages of a gate valve?

•    They are highly suitable for high pressure and temperature applications, and less maintenance is required.

•    The gate valve can also be used as bi-directional.

•    During the operation, the pressure drop is excessively less.

•    The closing feature is immensely good.

•    They provide minimum loss pressure and laminar flow.

What are the disadvantages of a gate valve?

•    The repairing of the gate valve such as grinding and lapping of seats are very difficult to maintain, due to extremely limited access.

•    It creates noise and vibration whenever it’s partially open.

•    It has an excessively slow operation process. The opening and closing of gate valves take a lot of time.

•    The flow of control cannot be controlled.

•    Start-up, maintenance and assembly require an extremely large space as well as money.

•    There is a possibility that leakages in the gate valve might occur.

What are the different types of gate valves based on bonnet and body connection?

Screwed bonnet: This simplest design is mostly used for cheap valves.

Bolted bonnet: This is the most well-known design used for a wide range of great valves.  A joint is required between the bonnet and the body and a gasket for sealing purposes.

Welded bonnet: There is no requirement for disassembly. In comparison to other bolted-bonnet counterparts, they have lightweight.

Pressure-seal bonnet: This is mostly used for high temperature and high-pressure applications. The higher the gravity pressure is, the greater the seal valve is.

What are the applications of gate-valves?

Butt welding or socket end-gate valves are used in lube oil, steam, feedwater, fuel gas, air, and other systems are the most typical applications. However, threaded-end gate valves in gaseous, air or liquid systems. In low temperature and low-pressure systems such as flanged gate valves, fire protection systems, water distribution pipelines or water piping is most commonly used.