Sitecna VB Volume Boosters with high flow threaded exhaust ports prevent the pilot gas from escaping to atmosphere which would happen with conventional designs. Often used with natural gas or anaerobic gas piloted control valves, the high flow exhaust port ensures fast response to the change in control pressure.
The volume booster is similar to a pilot operated pressure regulator in that the outlet pressure matches the signal port pressure and this is used to ensure sufficient air or gas supply is available to the valve actuator to deliver the appropriate response times.
In this case, a set of 8 volume boosters of 1/4" size, have 1/2" threaded exhaust ports to allow fast closure of the valve actuator that they supply gas to, and are ATEX and EAC Ex certified for hazardous area duty.