What is speed limiter?
Speed Limiter is a speed controller on shutdown valve, Needle valves are mostly used as speed limiters. The working principle for globe control valves is the same except that it uses its tiny plug to control the opening of its internal orifice.
Speed Limiter on Shutdown Valves:
The fluid control valve is placed straight before the device gas supply chain to the actuator in the vicinity of the solenoid valve. If we want to slow down the valve opening with this setup, we simply need to adjust this flow control valve so that the flow of instrument air supply to the actuator is slow.
If we want the valve to be opened or closed quicker, we simply need to change these flow control valves so that the stream of the water supply of the tool is quicker.
The flow control valves are already fitted with integrated control valves. This check valve allows the flow of the needle valve stream in the reverse direction quicker than the needle valves flow.
The device air venting from the actuator will be quicker by using this essential control valve. In other words, the device oxygen flow will be regulated by the needle valve to the actuator when the solenoid valve is energized.
But when the solenoid valve is de-energized, the device oxygen from the actuator will be vented through the control valve instead of the needle valve.