Why Is Cast Iron Best Suited for The Manufacturing of Pumps?

Mar. 16, 2022

Cast Iron Pump Casing

Cast Iron Pump Casing

Cast iron is preferred for various purposes including manufacturing of a range of pumps. It is best suitable for centrifugal pumps and sump pumps. Cast iron acquires some physical and mechanical properties that make it suitable for pump manufacturing. For high-temperature applications, a suitable metal is chosen for the manufacturing of pumps based on three factors.


Advantages of Casting:

1. Corrosion resistance

2. Maximum temperature limit

3. Coefficient of thermal expansion

1. Corrosion resistance:

A gradual increase in temperature makes the liquid to turn more corrosive. Cast iron has a relatively fair resistance to corrosion. Therefore, cast iron is preferred for pumps employed in high temperature applications.

2. Maximum temperature limit:

When there is a sudden fluctuation in the temperature, the metal is likely to experience a thermal shock. This could happen under situations like pouring hot oil into a cold pump for start-up or spraying cold water on a hot pump during cleaning. Cast iron pumps function up to satisfaction under a temperature of 650 degree Fahrenheit. They have considerably a fair resistance to failure caused due to thermal shock below this temperature. Heat treated ductile iron withstand failure up to 800 degree Fahrenheit.

3. Coefficient of thermal expansion:

The thermal expansion causes dimensional changes in the external parts of the pump which may result in the failure of the pump. Dimensional changes impact the running clearances and interference fits within the pump. Parts like the idler pins in the head, bushing in the casing and rotor bearing sleeve will lose their interference and will be forced out from place causing pump failure and an eruption of hot liquid in the area. The coefficient of thermal expansion of cast iron is only 6.5 and is comparatively low to that of steel and ductile iron with a coefficient of 7.0. This makes it ideal for pump manufacturing.

Ductile iron and malleable iron have good machinability, wear resistance, vibration damping and low notch sensitivity. They also have high heat resistance, ductility, strength and toughness. Moreover, cast iron pumps have durable thicker walls. This makes it resistant to shocks and knocks. It is also easy to maintain and repair in case of damages. Cast iron has a pH id 6 0r high and it corrodes to form a coating on the surface of the metal. This coating protects the pump from further corrosion. Cast iron has good casting performance, mobility and wear resistance than cast steel.

Cast iron sump pumps are durable and are suitable for a long term investment. A sump pump will generate high heat and a cast iron sump distributes heat from the motor evenly, thus increasing the life of the pump. Cast iron withstands high temperatures and a low chance of internal shock. It is less expensive compared to other metals and cast iron parts can be manufactured quickly. The overall capacity of the pump increases due to cast iron. We are a cast iron pump casing parts supplier. Please feel free to contact us if you need them!