Self-Regulating Pressure Control Valves

What are self-acting pressure control valves?
Self acting pressure control valves used to keep the adjustable set-point pressure within certain range in tanks or processes. It doesn’t request any auxiliary energy to operate valves but by the medium energy itself.
Since the self-acting pressure control valves do not need air supply or electric power to operate, so it’s kind of the most cost-effective pressure control valves to achieve a simple process of pressure control.

What are the different types of pressure control valves?
Nowadays, there are two types of self-operated pressure regulators, direct-acting self-operated pressure regulators, and pilot-operated pressure regulators.