WHEN TO REPLACE
VALVES AND SEATS
Valves and seats are easily the number one expendables cost, but this guide can help you reduce those costs by giving you visual indicators showing when it's time to change your valves and seats. We can’t tell you how many hours, stages, strokes, or pounds of proppant your valves will last due to the number of variables in play. However, by using these guidelines, you can extend fluid end maintenance schedules to minimize the number of times you need to pull covers and throw away good parts. If you have any questions - or need new valves, of course - we can help with that.
A brand new valve right out of the box – smooth insert and strike face. The operating principal is simple – the insert contacts the seat first and creates a seal, then the pressure differential forces the valve down until the valve’s metal strike face contacts the seat. The key point is the insert has to complete the seal; there can be no leak paths.
As the valve is used, both the strike face and the insert wear. However, unless a rock or other object is caught in the valve, the wear is progressive and predictable. Based on your operations and the guidelines below, you can make better decisions on valve condition and may be able to lengthen the period before pulling caps and checking valves and seats.
This valve has been is service a short time and has considerable life left. The insert wear has not bridged across the surface, so the valve's function is still good.
This valve has been is service a bit longer, but still has life left. The insert wear has not bridged across the surface, so the valve's function is still good.
On this valve, the insert damage is almost all the way across and the valve is on the verge of leakage, washout, and failure.
Replace seats when the strike face wear is 0.06 inches (1.50 millimeters) deep. Worn seats shorten valve life.