What is a Gate valve?
Gate valves are used to stop the flow of fluid by putting a rectangular gate or wedge into its passage. Gate valves take up extremely little space along the pipe axis and barely hinder fluid flow when completely opened, allowing gate valves to provide straightway flow with very little pressure loss. Gate valves are commonly utilised with bigger pipe diameters (from 2′′ to the largest pipelines) because they are less complex to build than other types of large-size valves. Due to the space constraints in which they are installed, greater sizes have recently been augmented with butterfly valves.
What is Valve Trim?
What are the parts of the Gate valve?
The parts of the gate valves are
- Body
- Bonnet
- Solid Wedge
- Body Seat
- Stem
- Back Seat
- Gland Follower
- Gland Flange
- Stem Nut
- Yoke Nut
- Handwheel
- Handwheel Nut
- Stud and Bolts
- Nuts
- Bonnet Gasket
- Lubricator
- Gland Packing
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Body:
The valve body is the primary pressure-retaining component, and it also houses the disc and stem. This also allows flow from the valve; its end connection is a pipe; this end can be welding type, threaded, or a variety of others depending on the size and pressure of the piping system.
Depending on the application, the valve body can be cast or forged in a variety of materials such as cast steel, stainless steel, and alloy steel.
Stem:
A threaded stem is spun to raise and lower the gate. The stem is rotated by the manual wheel or actuator. Depending on the design, the stem is divided into two groups:
- Growing stem
- The non-rising stem
Bonnet:
The Bonnet is the valve’s second pressure-retaining component. It is also known as a cover. We can make a valve enclosure by bolting, welding or threading it to the system.
The aperture in the gate, stop, or diaphragm wall allows the valve stream to flow through. Bonnet allows access to the internals of the valve during maintenance.
Seat
The gate valve is outfitted with two seats that carry out and maintain the gate seal. Seats for gate valves can be integrated into the valve body or in the shape of a seat ring. In the seat ring construction, seat rings are threaded or pressed into position and sealed welded to the valve body. The latter style of architecture is preferred for better temperature service. Integral seats are formed of the same material as the valve body, whereas pressed-in or threaded-in seats provide additional flexibility.
Disc:
This is the part that throttles or stops flow depending on its position. The disc is referred to as a plug or ball valve in the case of a plug or ball valve. When the wall is closed, a disc is seated against the stationary wall seat or seats.
It can be moved away from the valve seat by the action of the valve string, with the exception of the check valve and safety relief valve, which are moved away from their seats by fluid flow and pressure.
Nuts:
To tighten numerous parts together, nuts are nearly typically used in conjunction with a mating bolt.
Handwheel :
Handwheels are devices that rotate around an axis by hand. They are used to adjust machines and control compartment access. Typically, the rim serves as a grip; however, for simplicity of use, many handwheels include a stationary, revolving, or foldaway handle.
How does Gate Valve Works?
Gate valves are designed to regulate the fluid flow in pipelines. The fluid flow is controlled by the gate or wedge. The wedge of the gate or the shape of the gate might be round or rectangular plate-shaped.
It is also known as a gate valve disc. The valve opens and closes the gate valve. When the wheel with the handle is turned, the gate or wedge slides up and down across the flow of any fluid.
The Gate valve’s operation mechanism is as follows when you turn the handle wheel clockwise, the stem get moves down across the fluid flow, and the gate is securely situated between two seats.
So that there is no fluid loss when the valve is entirely closed.
Steam and liquid rise simultaneously across the fluid flow when the operator turns the handle wheel in the anticlockwise direction. The valve is opened in the Chrome closed state, allowing fluid to pass through the Gate valve.
Once the gate is entirely opened, the passage of any field is met with very little or no resistance.
Semi-opening conditions are undesirable because they promote gate degradation when fluid strikes. It also generates a great deal of noise and vibration.
Advantages and Disadvantages of Gate valves
Advantages
- Good shutoff features
- Construction is simple
- Process for production makes more efficient
- It can be used for both directions due to it bidirectional characteristics
- Pressure loss through the valve is minimal
Disadvantages
- Can’t open and close quickly
- Gate valves are not suitable for regulating or throttle flow
- Gate valves are sensitive to vibration while in the open state