The pneumatic actuator operates differently from the manual actuator: it uses gas (or compressed air) pressure to generate a force that operates the valve, without direct manual intervention.
In inert gas extinguishing systems… See more...
The pneumatic actuator operates differently from the manual actuator: it uses gas (or compressed air) pressure to generate a force that operates the valve, without direct manual intervention.
In inert gas extinguishing systems, the pneumatic actuator does not connect “directly” to the pilot valve as the manual actuator does, but receives a pressure impulse (usually from a nitrogen pilot cylinder – N2) that triggers its activation.
In practice:
The N2 pilot cylinder releases a small amount of high-pressure gas.
This gas is directed into the pneumatic actuator.
The internal pressure of the actuator moves the mechanism that opens the discharge valve of the main inert gas cylinder.
Typical characteristics of the pneumatic actuator
Response speed: designed to actuate the valve in very short times and allow gas discharge within the required safety limits.
Robustness and reliability: built with materials suitable to withstand typical system pressures (high pressures) and critical environmental conditions.
Compatibility with high-pressure valves
Maintenance: designed to facilitate maintenance operations, with interchangeable and accessible components.
Operational stability: operates even under variations in pilot gas pressure and resists phenomena such as minor leaks or temperature changes.
Single-way pneumatic actuator (1-way)
Has a single inlet for the pilot gas (usually nitrogen).
The pressure impulse opens the valve, but closing occurs only after the pressure is released or with the help of a return spring.
It is the simplest version, used where highly sophisticated control is not required.
Two-way pneumatic actuator (2-way)
Has one inlet and one outlet: the pilot gas enters and acts directly on the mechanism, allowing quick and safe valve opening.
It is the most widespread and standardized type in inert gas systems.
Three-way pneumatic actuator (3-way)
Has two inlets and one outlet.
Allows more flexible management because, in addition to the opening command, it can have a controlled return or discharge path.
Can be used in complex systems where rapid closure or system reset without manual intervention is required.
