Valves are very important components in utility systems. A gate valve, as the name suggests, is a type of valve that is used to control the flow of a liquid using a gate or plate. This type of valve is mainly used to completely stop or start the flow and is not used to regulate the amount of flow unless specifically designed to do so.
The best industrial valve manufacturers follow stringent standards while manufacturing these valves to ensure quality, durability, and performance. Any kind of sub-standard quality may lead to unwanted damage and economic losses. Efficiency and ease of operation are two very important factors when choosing a valve from the plethora of vales available in the market.
Sluice valve is called by gate valve, look through to know more info about them.
What is A Gate Valve?
Source: TWS Valve
A gate valve is a type of isolation valve used to control the flow of fluids in an industrial system. A sluice refers to an artificial channel aided by a gate to control the flow of water. Sluice valves or industrial gate valves are mainly used for industrial purposes. Its easy and simple mechanics make it one of the most-used valves across various industries. The valve operates by simply moving or lifting up the barrier in the path of flowing liquids.
It is used along the pipe in a one-directional or bi-directional flow. When fully open, it hardly provides resistance to the flowing liquid, which is one of the major reasons why it is considered very efficient. The shape of the gate maybe be parallel, but in many cases, it is kept in a shape of a wedge. Wedge gate valves help create a better sealant when closed as it applies pressure to the sealing surface and offers better sealing performance.
A gate valve works by manual rotation of a handheld wheel, or it uses an electric or pneumatic actuator. Rotation of the wheel a number of times moves the gate up and down, which controls the flow of liquid or gas inside the valve. Opening the gate provides minimal obstruction to the flow but keeping the gate half open may cause damage as the flowing liquid or gas will exert a large amount of pressure on the plate. Instead of gate valves, globe valves can be used to regulate flow.
Operation
Although a gate valve or sluice valve is easy to operate, it consists of numerous components fixed together for it to function efficiently. This type of valve consists of the body, a gate, a seat, a bonnet, and in some cases, an actuator which automates the flow. Gate valves can be manufactured using various materials; however, stainless steel is the most preferred since the material is more resistant to changes in temperature or pressure. The various parts of a gate valve are detailed out below.
The Gate
Available in a variety of designs, the gate is the main part of a gate valve. The main design aspect of it is its sealing capacity for specific applications. A gate valve can be classified as a parallel or wedge-shaped valve based on the gate type. The former can further be divided into slab gates, parallel slide gates, and parallel expanding gates.
Seats
A gate valve has two seats that ensure sealing along with the gate. These seats can be integrated within the valve body, or they can be present in the form of a seat ring. The latter is threaded or pressed into its position and then sealed and welded to the valve body. In situations where the valve is subject to higher temperatures, seat rings are preferred, as they allow for more variation in design.
The Stem
The gate in a gate valve is lowered or raised when it spins on a threaded system. This can take place via a manual wheel or an actuator. An actuated gate valve can be controlled remotely. Depending on the type of step, the gate valve can be categorized into rising stem and non-rising stem valves. The former is fixed to the gate, whereas the latter is fixed to the actuator and threaded into the gate.
Bonnets
Bonnets are valve components that ensure the safe sealing of the passage. It is either bolted or screwed to the valve body so that it can be removed for replacement or maintenance. Based on application, various types of valve bonnets include bolt bonnets, screw-in bonnets, union bonnets, and pressure seal bonnets.
Applications
Gate valves or sluice valves have numerous applications in various industries and have diverse uses in controlling liquid, gas, and even airflow. In environmentally harsh conditions such as high-temperature or high-pressure areas in petrochemical industries, gate valves are the go-to instrument. In such conditions, the material and type of valve play an important role in the performance and efficiency of the valve.
Gate valves also find their use in fire safety systems, where a flanged gate valve is commonly used. Non-rising stem gate valves are used in ships or underground at places where vertical space is limited.
Types Of Gate Valves
Source: TWS Valve
Parallel And Wedge-Shaped Gate Valves
As the name suggests, parallel slide gate valves have a flat, parallel-faced gate that is fitted between two parallel seats. On the other hand, wedge gate valves have a wedge-like gate element. This has ribs on both sides and is guided into position by the slots in the gate body. These wedge guides help transfer axial loads imposed by the medium to the valve body, enable low-friction movement, and prevent the rotation of the wedge whilst moving between open-closed positions.
Rising Stem And Non-Rising Stem Gate Valves
The primary difference between these two types of gate valves is that they are either fixed (rising) or threaded (non-rising). In rising stem gate valves, the rotating stem rises while the valve opens. However, this valve type is not preferred where the space is limited or the installation is underground.
Metal Seated And Resilient Seated Gate Valves
Both of these are wedge gate valves. In metal seated valves, the wedge slides toward a groove in the gate valve body and could trap solids that the fluid may contain. Hence, resilient seated valves are preferred where tighter-shut off is required, like in water distribution systems.
In resilient seated valves, a wedge is enclosed within an elastomer which ensures a tight seal. The seating takes place between the valve body and the wedge and hence does not necessitate a groove as in the case of a metal seated gate valve. Since these valves are coated with an elastomer or a resilient material, they offer a higher degree of corrosion protection.
Final Words
Sluice valves and gate valves are different names for the same type of valve. These are the most common type of industrial valves in use. As gate valves are manufactured using various materials and have numerous types, the type of valve must be selected carefully for specific applications.
Good quality and efficient valves like the ones by TWS Valve are a great investment as it requires minimal maintenance in the long run, which can save a lot of money. Contact Valve TWS Valve today for best-in-class valves.
Post time: Mar-02-2023