Difference between shut-off and isolation valves?Unival

The auxiliary valve market offers several component models, with different applications, but with the same quality in terms […]

The auxiliary valve market offers a variety of component models, each with different applications but with the same quality in terms of raw materials and durability. Two very common types of valves, widely used in oil and gas companies, general industries, the naval sector, and locations with fluid pipelines, are shutoff valves and isolation valves.

Although the names are somewhat similar and can even cause some confusion among laymen, these two valve segments encompass quite different supplies. In the block valve category, we can list butterfly, ball, gate, globe, and needle valves. Among isolation valves, we can list absolute block valves and check valves. Understand the main differences!

Important differences between shut-off and isolation valves

Shutoff valves allow a substance to flow only one way, blocking the opposite direction. Isolation valves, on the other hand, have two inlets and are designed to isolate a specific section of the system. When one side of the valve is sealed, the other becomes available.

More differences:

The stop valve stops a flow;
The isolation valve, as the name suggests, isolates a certain part of a system;
The shut-off valve only works fully when it is fully open or fully closed;
The isolation valve is always open and is only closed for maintenance;
The shut-off valve can be used in general purpose lines;
The isolation valve can be used in chemical, power generation, mining companies, among others.

Check out the features of each type of shut-off and isolation valve!

Shut-off Valves

Butterfly – It has a wheel disk around the axle, parallel to the fluid in an open system and perpendicular to the fluid in a closed system. It is effective for low pressure.

Spherical – Features a spherical shutter in the tubular body. Widely used in the naval industry. It has a cylindrical passage and can be in the open or closed position.

Drawer – Has a small obstruction to the flow of fluid when fully open. It has a shutter sealing system. They are used in systems that do not require constant opening and closing.

Globo – Ideal for systems with frequent opening and closing. Controls various flow rates. Globoid shape.

Needle valve – Similar to a globe valve in operation. It has a needle plug as a sealing element. Commonly used in steam lines.

Isolation Valves

Absolute shut-off valve – With zero leakage, this valve is widely used to shut off gases and liquids. It allows for quick shut-off and can be positioned anywhere within the pipeline.

Check valve – Automatically prevents backflow into the piping. Available in different sizes for use in high-pressure and high-temperature conditions.