What is the Difference Between a Ball Valve and a Butterfly Valve?
As the engineers test piping systems for industry, they generally analyse ball valve vs butterfly valve. Both types are quarter-turn rotary valves for on/off service, but they have substantial differences in design, sealing performance, pressure capacity and application.
A ball valve uses a ball which has a hole through the middle, rather than a disc. When the hole is in line with the pipeline, flow is allowed to pass through, when the ball is turned 90 degrees the the solid part of the ball obstructs the flow. Excellent shut off, low pressure drop, and reliable sealing after long storage time can be obtained with this design.
In a butterfly valve, there is a rotating disc that is connected to a shaft running perpendicular to the flow, which is the main difference. The disc rotates in the pipe to increase, decrease or cut off flow. In general, butterfly valve are lighter, more compact and cheaper than ball valves especially in larger sizes (over DN300 / 12").
Ball valves are used for high pressure, high temperature, and critical isolation service where there can be no leakage of the isolating fluid. They are widely employed in the oil and gas, hydraulic, and chemical processing industries. Yet they are costly and unwieldy in large sizes.
Butterfly valves are primary choice in water treatment, HVAC, fire protection and general services. Their lightweight profile minimizes structural support and installation requirements, which is especially suitable for projects with limited space.
The range of butterfly valves includes several different types and styles of connection:
Lug Type Butterfly Valve: Tap the lugs of the body to House the bolts, that with which can slip the one end of the valve between two flanges and the other end can served as dead end.
Flange Type Butterfly Valve: With Integrally Casted Flanges For Direct Bolting To The Pipeline Flanges.
Double flanged butterfly valve – is flanged on both ends; used for high-pressure water and wastewater applications.
Grooved type butterfly valve: Employs grooved ends for use with quick connect couplings; popular in fire protection systems.
Wafer Type Butterfly Valve: Hooked between flanges and the bolts which hold the flanges travel through the valve body.
Ductile Iron Flange Type Butterfly Valve and Ductile Iron Grooved Type Butterfly Valve: Provide high strength to weight ratio for water supply systems.
Cast Iron Lug Butterfly Valve: Economical solution suitable for low pressure services.
Fireproof Wafer Butterfly Valve and Manual Fireproof Wafer Butterfly Valve: Constructed with fully fire-safe seats and materials that conform to the requirements of API 607/API 6FA for fire protection systems.
Ductile Iron Fire-Fight Wafer Butterfly Valve: Purpose-built for fire mains.
Pinless Lug Type Butterfly Valve: Removes drive pins, which can cause galvanic corrosion and fugitive emissions.
Pinless PTFE Lined Butterfly Valve and Halar Lined Pinless Butterfly Valve: Come with anti corrosion linings for aggressive chemicals services.
Selecting ball valves for small-bore high pressure or bubble tight isolation. Select butterfly valves for large diameters, moderate pressures, frequent operation, or sensitive cost considerations. For the fire protection system, use fireproof wafer type butterfly valves; for corrosive media, use PTFE or Halar lined pinless designs; for waterworks, ductile iron flanged or grooved types are the norm. The correct choice provides and efficient, safe, and cost effective operation.