Isolation Valves vs Gate Valves: Are Both The Same?

Home Isolation Valves vs Gate Valves: Are Both The Same?
07/09/2022
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In a fluid handling system, an isolating valve stops the flow of process media to a specific location. It isolates the fluids to keep them from reaching their destination. A gate valve pretty much works the same. However, its purpose distinguishes it from an isolating valve.

A gate valve is used in industrial pipes to stop the flow of process media. It aims not to isolate the media from reaching a particular location but to separate it so that it does not harm the system. However, several others exist besides this feature to help learn everything about isolation valve vs gate valve.

So, let’s discuss them in detail here.

What are Isolating Valves, and How Do they Function?

Red Gate Valve
Source: Deposit Photos

When a valve is in the open position, the media inside the pipe starts to flow. But when it is in a closed position, the fluid stops flowing. It opens or closes a flow is known as isolation or an on/off valve. Although a gate valve has a similar purpose, they are different from each other. Distinguishing isolation valve vs gate valve helps understand their applications effectively.

According to industry standards, an isolating industrial gate valve must be of an indicating type. An indicating valve provides an easily distinguishing visual method to determine their open or closed status.

Gate and ball valves are the two most common types of isolating valves available today. Before deciding which one to pick for a particular application, it is essential to know them thoroughly to make the right decision. While a gate valve is a better option for some processes, an industrial valve is suitable for heavy-duty industrial use.

Isolation valves divert the process media to facilitate maintenance, shutdown, and equipment removal. This linear movement valve is a critical component of any fluid system as it stops the flow of media into a particular area of the system. In some applications, it manually controls the fluid flow and is intended for use only in closed or fully open positions.

Applications Requiring the Use of Isolation Valves:

An isolation ball valve used in a variety of applications where on or off type control is required:

  • Divert process media,
  • Isolate the media flow,
  • Facilitate maintenance,
  • Remove the equipment,
  • Permit plan shut down.

Over the years, many types of isolation valves have been developed to meet the above range of applications and the diverse operating conditions of the industries.

They are further classified into two categories according to the operating motion of the closure device or obturator:

  • Linear motion valves: The obturator moves in a straight line in these valves. It includes gate, diaphragm, pinch, and China actuated globe valve. They are created from the early forms of sluice gates to regulate the flow of water in irrigation channels. Since then, its various designs and types have been developed for almost every flow application.

The fluid flow in a linear motion valve is typically at the right angle to its straight-line obturator movement. Besides, these valves offer a tight shutoff by tightening down the obturator on a threaded stem.

  • Rotatory motion valves: In these valves, the obturator rotates an axis at a right angle to the flow direction. The two most common and vital rotatory valves are associated with steam applications.

Here are Some Common Types of Isolation Valves:

Let’s discuss some of the most common types of isolation valves provided by industrial valves manufacturer:

Pinch Valves

This valve operates by pinching a removable, disposable tube that opens and closes the flow route. Although not officially regarded as an isolation valve, pinch valves use a disposable tube to play a similar role as an isolation valve by isolating the media from the valve system.

Diaphragm Valves

Also known as a membrane valve, a diaphragm valve is a solenoid-operated device employing a diaphragm to seal the valve seat and isolate the flow path. One may configure diaphragm isolation valves like rocker-style valves as easy two-way or three-way on or off systems.

Rocker-style Valves

A rocker-style butterfly isolation valve is a solenoid-operated device using a rocker system that rotates to seal the valve seat and isolate the flow route. One can configure these devices as easy two-way systems, multi-port diverters, or selectors.

How is a Gate Valve Different From an Isolating Valve?

Industrial Valves
Source: Deposit Photos

In a fluid handling system, an isolating valve is attached to the supply line of an appliance and features one compression connector at each end. Gate valves are standard in domestic water systems, but their popularity in the industry has declined over the years. But they are still employed in applications requiring an uninterrupted media flow.

A gate valve functions by retracting into the bonnet to create minimal pressure drop when it is in an open state. They are specifically intended for use in isolation applications in an industry pipe. They feature four main components: body, bonnet, gate, and stem. Its entrance lifts 90-degrees to the fluid flow, sliding between the seats to clear the path. It fully retracts into the bonnet to ensure a low-pressure drop across the valve.

Gate valves are multi-purpose bi-directional shutoff devices that shift the wedge up and down in a vertical direction inside the valve body. Depending on the design of the gate and its seating faces, a China electric knife gate valve is further divided into several classes.

Here is a quick table to understand everything about isolation valve vs gate valve used in the fluid handling system:

BASIS OF DIFFERENCEISOLATION VALVESGATE VALVES
SHUT OFFIsolating valves offer a quick shutoff.Gate valves offer a slow shutoff.
LONGEVITYIsolating valves last for a long time and are less prone to damage.Gate valves do not last long and are more prone to corrosion at the valve stem than isolation valves.
COSTAn isolation valve is costlier than a wholesale actuated gate valve of similar specifications.Gate valves are usually more affordable than isolating valves of similar specifications.
NUMBER OF PORTSThey feature two or more ports.They feature two ports at the most.
SEAL OR LEAKAGEThey offer tight sealing and leakage class IV for a metal-seated isolating valve.They are more prone to leaks compared to isolating valves.
REQUIRED SPACEIsolating valves require more space to install a quarter-turn handle.Gate valves require less space to install a 360-degrees shutoff handle.

Parting Thoughts

Like all other isolating valves, gate valves are also isolation valves. They are employed in commercial and industrial applications to separate the fluid flow from the system. Because of their capacity to cut through the liquids, they assist in maintenance and replacement activities.

Although a few differences exist, it would not be wrong to say that a gate valve can be an isolation valve. But vice versa is not possible. An isolation valve is a term used to describe the purpose of a valve. Please contact us Dombor Valve to purchase reliable and long-lasting isolation and gate valves for any application.

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