How Butterfly Valves are used in different applications

If you have ever wondered how and why butterfly valves are used in different applications, let BM Engineering Supplies talk you through their various characteristics, capabilities and applicable applications.

Types of Butterfly Valves

There are different kinds of butterfly valves, each adapted for different pressures and different usage. The zero offset butterfly valve, which uses the flexibility of rubber, has the lowest pressure rating.

The high performance double offset butterfly valve, used in slightly higher-pressure systems, is offset from the centre line of the disc seat and body seal (offset one), and the centre line of the bore (offset two). This creates a cam action during operation to lift the seat out of the seal resulting in less friction than is created in the zero offset design and decreases its tendency to wear.

The valve best suited for high-pressure systems is the triple offset butterfly valve. In this valve the disc seat contact axis is offset, which acts to virtually eliminate sliding contact between disc and seat. In the case of triple offset valves the seat is made of metal so that it can be machined such as to achieve a bubble tight shut-off when in contact with the disc.

Regulating fluid flow

Butterfly valves are best suited for regulating fluid flow. The actuator outside the valve can be fixed to an automatic mechanism, or remote control mechanism, that controls the desired flow of the liquid. The actuator or the valve spindle can also be attached to a lever for manual control of the valve.

Butterfly valves work similarly to ball valves. Rotating the handle, either manually or with a pneumatic system, turns the plate perpendicular or parallel to the flow of the fluid. Butterfly valves can also be used for regulating flow by adjusting the lever and keeping a close eye on the desired output flow.

Butterfly Valve Applications

Butterfly valves are used on ships, firefighting apparatus and domestic piping. On ships they are used for large capacity lines, such as forward and aft sea water suction lines. Butterfly valves can also be used across a wide range of other applications, performing particularly well in large volume water applications and slurry applications.

The following are some typical applications of Butterfly valves:

• Cooling water, air, gases, fire protection.
• Slurry and similar services.
• Vacuum service.
• High-pressure and high-temperature water and steam services.
• Compressed air or gas applications.

Speak to one of BME’s knowledgeable advisers about our full range of butterfly valves today by calling 0141 762 0657 or email sales@bmengineering.co.uk.