Fluid Cylinder / Valve Body – The Main Pressure-Bearing Housing of the Mud Pump Fluid End
(Commonly referred to as the Pump Head or Valve Pot / Valve Box)

The fluid cylinder is the main pressure-containing body of the fluid end in a drilling mud pump, serving as the core pressure-bearing chamber. It houses the liner, piston, suction valve, discharge valve, and valve seats. The piston reciprocates within the liner, creating volumetric changes inside the fluid cylinder chamber, thereby enabling the suction of drilling fluid under negative pressure and the high-pressure discharge of fluid.

The fluid cylinder assembly consists of the cylinder body and its built-in components, which are divided into two main valve assemblies:

• Suction Valve Assembly

• Discharge Valve Assembly