LESSON 10 · INTERMEDIATE · SHORT LESSON
Check Valves
A check valve permits flow in one direction and blocks reverse flow. A pilot-operated type can be opened in a controlled manner.
What is happening technically?
Cracking pressure, flow direction and pilot ratio affect selection. Assess sealing requirements against the manufacturer's limits.
In practice
A load-holding valve may not open if pilot pressure is insufficient.
● Pressure / supply● Return┄ Pilot (illustrative)
Educational diagram only; not a manufacturing or safety circuit. The pilot line illustrates the line style only.
Symptom → check → solution
If movement, pressure or temperature changes, first identify the conditions in which the symptom occurs. Record existing gauge readings. Base maintenance or circuit examination on causes confirmed by measurements.
Select your symptom in Fault Hunter →Quick check
Which is the correct approach before replacing a component?