All About Mud Pumps

A mud pump is a piston driven pump design that can produce high-pressure operations to safely transfer high viscosity fluids over an extended depth. The mud pump has many applications in industrial service, but it has proven to be invaluable in many drilling operations. Let's take a look at mud pumps and why they are such a good fit for the industries they serve.

Related Blog: All About Submersible Pumps

Mud Pump Design

A Mud pump is a reciprocal pump design utilizing a piston in a cylinder to transfer fluids under high pressure. A mud pump can generate up to 7,500 psi (52,000 kPa) during normal operations. Mud pumps are a positive displacement design.

Mud pumps are available in a variety of configurations and sizes. However, mud pumps tend to be one of two main types:  the duplex and the triplex. The duplex mud pump features two pistons (or plungers) in constant action to move the fluid.

The triplex mud pump has all but replaced the duplex version in most applications, although you will still find the latter in use in some smaller countries. The triplex mud pump features a triple piston (plunger) design that is more efficient than the duplex design.

The latest designs of the mud pump are the quintuplex and hex versions. As the name suggests, these designs feature five or six pistons in a reciprocating design. Although not in widespread use as compared to the triplex design, these mud pumps spread the pumping action across the rotational cycle, creating less mud noise. This allows for better measurements and logging to take place while in operation.

Mud Pump Parts

There are two main parts to a mud pump: the fluid end and the power end. The fluid end is where the actual pumping takes place. The components of the fluid end consist of valves, pistons (or plungers), and liners.

Since the fluid end is in constant contact with the material being pumped, most modern designs allow for quick replacement of worn components as needed. This dramatically extends the life of a unit without having to completely replace the pump.

The power end of a mud pump is responsible for taking the input power, typically through a driveshaft, and converting it into the reciprocating motion needed for the pistons. In most mud pump applications, the power end uses a crosshead crankshaft for this conversion.

How They Work

Rotational power is supplied to the mud pump through an external power source. The power end of the pump converts this rotational energy through a crankshaft to a reciprocating motion that moves the pistons.

The pistons move back and forth in their liners, exerting a force on the cylinder chamber. During the retraction of the piston, valves open to allow the fluid to be drawn into the cylinder. Once the piston has fully retracted, it is pushed back into the cylinder.

At this time the intake valves are closed and the exhaust valves open, allowing the piston to force the fluid out of the cylinder under pressure. Once the piston reaches its maximum depth into the cylinder, the exhaust valves close and the process repeats.

Support Components

Due to the pressure and material being pumped, most mud pump applications can create a lot of vibration. To combat this, many mud pump applications incorporate pulsation dampeners. These are typically used on both suction and discharge sides of the pump.

In some cases, a positive displacement pump may pull the fluids at a pressure lower than its vapor pressure. When this happens, damaging cavitation can take place. In these cases, a charge pump might be required at the inlet side to maintain a positive pressure on the suction stream.

Pump Parameters

When selecting a mud pump, there are two main parameters to be used, pressure and displacement. Pressure is the net pumping pressure that the pump can safely provide. The requirement for pressure increases as the drilling depth and fluid (or slurry) viscosity increases.

Displacement is the volume of fluid that the pump can transfer within a given time period. In most applications, this is rated as discharged liters per minute.

Applications

Mud pumps are ideal wherever a lot of fluid needs to be pumped under high pressure. They are considered an essential part of most oil well drilling rigs. Mud pumps can deliver high concentration and high viscosity slurry in a stable flow, making them adaptable to many uses.

Mud pumps are an invaluable tool when high pressure and high viscosity fluids are needing to be transferred. Mader Electric, Inc. specializes in mud pump repair and installation, as well as pump training. Contact us to see how we can help with your pumping needs.