Valves and Seats

The volumetric efficiency is strongly influenced by the condition of the valves. This means that regular inspection is a necessity if the efficiency is to be kept optimal.

After inspection, the valves should always be returned to the seat from which they came. Valves and seats tend to wear together with matching wear patterns. They will give longer service if they are kept together.

After renewing a seat, the valve should always be replaced. The valve is equipped with fins or a guide pin to ensure good alignment in the seat. A valve spring helps to close the valve.

Most valve seats are tapered on the outside to fit tightly into the pump body. The mating faces must be thoroughly cleaned, as improper seating could lead to a washout in the body (Drill Pipe Washouts), which could spoil the entire fluid end.

As the fit of the valve seats must be very tight, the valves must be driven into position with a copper bar and removed with a special (hydraulic) pulling tool.