Volute Pump Casing

Product Information

Application

Water pump is a kind of pumping machinery that use water's centrifugal movement when working, composed of a pump casing, impeller, pump shaft, motor, etc. The pump casing has various kinds of materials, below we introduce cast iron and cast steel for your reference.

Cast Steel Application

For the corrosive and hazardous petroleum products application, specific cast steel or stainless steel is required. Martensite stainless steel is often used in boiler feed pumps and many hydrocarbon applications. Martensite stainless steel has good mechanical properties and is suitable for high-pressure conditions. In chemical applications and other corrosive environments, austenitic stainless steel is usually used. In addition, austenitic stainless steel can effectively resist the corrosion caused by the high speed, and also can be welding repaired on-site relatively. A high-pressure shallow sea water injection pump has higher requirements of corrosion resistance and mechanical properties, so it's better to select the duplex stainless steel (50% ferrite +50% austenite).

For pressure beyond 16Mpa, cast steel is the most suitable material for the pump casing and other pump parts.

Cast Iron Application

For single-stage pumps, gray cast iron has the enough strength to resist pressure.

For medium pressure and temperature ranges, ductile iron is widely used.

For the condition where the corrosion resistance of gray cast iron and ductile cast iron is insufficient, high corrosion resistant nickel cast iron is often used as pump body material.

In recent years, a new type of corrosion-resistant high nickel cast iron material (named D2W) with good welding performance has been developed, which contains a small amount of niobium to improve its welding performance. Typical austenitic cast iron containing 15%~20% nickel is widely used in brine.