Mud Pump Speed
The number of strokes per minute of the piston pump that circulates the drilling mud. Mud pumps typically work in the 100–200 rpm range; the drive engine turns much faster and there is a gear or belt reduction in between. Pump speed directly determines the circulation flow.
The chain is as follows: the speed of the diesel engine, divided by the reduction ratio, gives the pump speed; the pump speed multiplied by the stroke volume gives the flow. When you change the engine speed you are in fact moving the first link of this chain.
What the operator needs is usually flow: a certain circulation rate is required to carry cuttings out of the well. Giving the speed steplessly and repeatably with a potentiometer, instead of setting it by hand and by approximation, makes it easier to correct quickly as the formation changes. The three-channel structure of the GS740-3P is built exactly for this scenario, for driving several pump engines separately from the cabin.
Its limits must also be known. The system does not measure the pressure of the pump or the speed of the engine; it drives the position of the throttle lever. The relief valve, the pressure gauges and the engine's own protection chain must be present separately, as this control does not take their place.
Context in which this term is used: Speed control of three pumps in drilling