Sequence valves, decompression, counterpression and balance Le S3-P, S5-P, U3-P, U5-P, T3-P, T5-P, X3-P, X5-P are hydraulic control valves, normally closed, used for pressure control, for plate assembly. They are respectively: sequence valves, unloading, counterpression and balance valves (three -way reduction). Available in four pressure adjustment fields and with no return valve for reverse free flow.