Product introduction

The piston assembly is one of the main parts of the hydraulic end system of the mud pump.The discharge pressure of the mud pump is generated by the reciprocating linear movement of the piston assembly within the piston.The piston assembly is composed of piston core, rubber, clamp spring, pressing plate, etc.The piston core is made of 42CrMo, and the piston rubber is made of nitrile rubber or polyurethane rubber.

Piston and cylinder liner (some do not have cylinder liner and directly with the inner wall of the cylinder) constitute a pair of dynamic seal, seal elements are assembled on the piston.Through the reciprocating movement of the piston, alternately changing the volume of the working chamber, with the help of the pump valve to achieve the pump suction, discharge process.

Therefore, the piston is required to have:

1. Good sealing;

2. Sufficient strength and stiffness

3.The connection and positioning of piston body, piston rod and piston ring should be firm and reliable.

The material classification

Nitrile rubber(NBR)

It is suitable for general drilling environment with operating pressure below 20Mpa and operating temperature no higher than 120℃.Excellent wear resistance, chemical corrosion resistance, long service life in normal drilling environment.

Polyurethane rubber(PU)

It has excellent oil resistance and wear resistance.The working temperature is no higher than 120℃, suitable for the working environment with oil-based mud and high sand content under the working pressure of 35Mpa.

Hydrogenated nitrile rubber(HNBR)

Suitable for high temperature, high pressure, high corrosion working environment, working pressure of 75Mpa, operating temperature up to 150℃.Hydrogenated nitrile rubber is a type of rubber used in aviation.Used in the petroleum industry, hydrogenated nitrile rubber has the properties of abrasion resistance, oil resistance and chemical resistance, as well as amine-resistance and steam resistance.Especially in the high temperature, high pressure working environment, other rubber in the hydrogen sulfide, carbon dioxide, methane, steam and acid under the action of the rapid destruction, but hydrogenated nitrile butadiene rubber has shown a good comprehensive performance.