Question

What happen on pressure in sudden compressing of air in piston cylinder?

Answer 1

Pressure increases.

The pressure simply rises to the value of relief set pressure and thereafter the pressure gets relieved.

Relief valves/safety valves/overload relief valves are designed to limit the pressure in the system to a predetermined value. They act almost similarly to a fuse in an electrical circuit. Whenever there is high current or spike beyond the rating of the equipment or wiring, the fuse gets blown & hence the equipment is protected from such surges.

Look for the rated pressure on any equipment or a system. That usually gives the overload setting of relief value for that system/equipment.

Hope it helps.......