PRSQ series Pressure Sequence Valves are used in a hydraulic circuit, multiple cylinders are used to run elements such as engines at different times and at different pressures. The operating principle is similar to pressure safety valves. Normally closed. It opens at the desired pressure and activates other user elements. Pressure sequencing valves in a hydraulic system, the main line pressure value and adjustment are located on stream reaches when they'll next open or shut the hydraulic system.