Typical Gate Valve Uses
A gate valve, also known as a sluice valve, is a type of linear valve consisting of a body, bonnet, gate or stem that is used to open or close pipelines. Gate valves are one of the oldest valve types and are manufactured from various materials including – Nickel Aluminium Bronze, Super Duplex and Titanium.
Today, gate valves are used in several industries such as oil and gas, water treatment, power generation, pharmaceuticals, oil and gas pipelines and gas applications. Read on to learn about the different types of gate valves and their uses.
What are Gate Valves and How Do They Work?
Gate valves are fittings used for controlling and isolating the flow of liquids and gases. When fully open, they allow a full flow of fluid, but when fully closed, they completely block the flow. The gate moves across the body seats by the stem, shutting off the flow of fluid.
Usually, a gate valve requires manual actuation requiring a turn of 90 Degrees via a handwheel or lever placed on the top of the valve. The stem goes up and down to lift the wedge up the body to let water through or block it from flowing entirely.
The value of such valves lies in the ability of the fully opened valve to allow the flow of liquid through with little resistance or a significant pressure drop, unlike some other types of valves. This is because, in the open position, the mechanism does not obstruct the flow path.
Gate valves play an important role in many industrial infrastructures, as they allow for the effective control of liquid and gas flow. There are numerous types of gate valves available, each one with its advantages and disadvantages.
A gate valve allows liquid and gas flow to be effectively controlled in many industrial infrastructures.
Types of Gate Valves
Gate Valves with Rising Stems versus Non-Rising Valves
Gate valves are classified and manufactured as either rising stems or non-rising stems.
Rising stem gate valves are beneficial because they provide a visual indication of the valve’s position, allowing for easier identification and troubleshooting. Their external stem allows for ease of lubrication and examination.
In non-rising gate valves, the stem is threaded into the disc which isn’t visible. Once the handwheel on the stem is rotated, the disc travels up or down the stem as the valve opens. The more compact design of these valves allows for installation in areas where space is at a premium. Non-rising stem valves can be suitable for underground installations.
Gate valves are a highly versatile solution for several industrial applications, some types are summarised below:
Wedge Gate Valves
There are two main types of wedge gate valves: solid wedge gate valves and flexible wedge gate valves.
Solid Wedge Gate Valves
The solid wedge is a single-piece solid disc construction and is practically for turbulent flow.
The disc is wedge-shaped and often specified when the valve is sealed against two separate sources of flow and is required to prevent contamination between these two sources and can be used in cold or ambient water lines.
A flexible wedge is a one-piece disc construction just like a solid wedge gate valve and contains a cut around the perimeter to improve the ability to correct mistakes or changes in the angle between the seats. Its flexible disc has the appearance of two wheels on a very short axle. It has been developed to overcome any possible jamming at high temperatures of the solid wedge.
Parallel Gate Valves
Parallel slide gate valve compact design and assembly consist of two interchangeable spring-loaded discs which are held against parallel body seats by a spring. It has a sliding action as the discs move across the seats, which has the effect of wiping the seat surface helping to remove any particles or contaminates between the seating surfaces.
They can be used with a variety of end connections, delivering reliable closing, good sealing performance and longevity that requires minimal maintenance.
Knife Gate Valve
This type of gate valve is similar to a parallel gate valve, which uses a blade or knife-life gate to open or close and prevent fluid flow. As the gate moves into position it slides across the seating faces which helps to clean it and isolate difficult media.
The knife gate valve is often used in mining, slurries, sewage, wastewater and pulp paper industries.
The bonnet style of gate valves can be bolted or union style and is likely to house the internal components. One key advantage of the gate valve is that the gate fully retracts into the bonnet and creates a minimum pressure drop when the valve is fully opened.
The Benefits of a Gate Valve over other Valves
Gate valves are an essential part of pipeline and process infrastructure and offer several benefits.
- No restriction of flow through the bore when the valve is fully open.
- With a properly sized gate valve, a smooth, even flow rate, with minimal losses of pressure or turbulence, can be maintained.
- Top entry valves like gate valves make it easier to carry out full repair and refurbishment of the valve with the body remaining in the pipeline.
- Metal seated provides long service life in elevated temperature conditions.
Why Gate Valves are used in various industries
Gate valves are used extensively in industrial applications due to their ability to effectively control the flow of liquids and gases. Their robust construction makes them reliable and capable of withstanding challenging conditions, as well as being cost-effective in comparison with other valve types.
Moreover, the simple design requires minimal maintenance, when compared to other types on the market, making them a popular choice for various industries such as gas processing, chemical storage, manufacturing or wastewater treatment.
All in all, gate valves offer several advantages that make them extremely desirable options within the industrial environment.
Gate valves are manufactured in a wide range of sizes for use in heavy industry. Shipham Valves manufacture high-quality gate valves as small as 1/2″ up to larger sizes of 48″. Large sizes are available on request.
When Not to Use a Gate Valve
Gate valves are not suitable for use in applications where throttling is required. Their design isn’t ideally suited to fluid flow slapping against a partially open gate, which can cause extensive damage to the valve. Other valves, such as the butterfly valve may offer an alternative solution, where there is a need to regulate flow.
If you require further information about the best valve for your application, please contact us.
Gate Valves have been used for many years and have since evolved to serve the changing needs of the flow industry. Whether it be for controlling and isolating liquids, gases or steam, the gate valve provides an effective, robust and reliable valve solution. With proper maintenance, gate valves can last several decades (often the length of the project) without requiring repair. From chemical processing applications to water treatment to the petroleum industry.
We hope this has helped you better understand the key features, uses, types and benefits of gate valves so that you can determine which valve meet your needs.
If you’re still uncertain or would like to learn more about specific models offered by Shipham Valves Ltd, feel free to contact us.
Our helpful customer service team is always happy to answer any questions or provide assistance with selecting the appropriate gate valve for your project.