Originally posted by Control Man 60 PSI is a bit TOO HIGH for Commercial Pneumatic devices 30 PSI is the MAX that most devices will handle.
I have a system where a 20# line goes to "normal" devices such as thermostats and small actuators and a 60# line goes to large "Commercial" devices --Cooling tower by-pass valves, Bray valves on boiler headers etc.
Very common applications. 20# circuit is protected by a 30# relief valve and 60# circuit is protected by 75# relief.
Also have systems with a 100# riser and each floor has a pressure reducing station to knock the pressure down to what is required for each branch.
I have several 60 psi devices is some of the larger buildings I service, usually a large (8 inches and up) chilled water valve or bldg deny valve requires higher psi for close off force againsed 140 psi water.Same setup as powerhead stated, 100 psi 1/2 riser (15 story bldg) with regulator/relief station at each floor with end of mains looped into itself.
Your VALVES ( BRAY and 8" and up ) are not the NORMAL COMMERCIAL application type devices and the part about MOST DEVICES in my posting would cover that.
In nearly 30 years of pneumatics very seldom ran across anything from the normal COMMERCIAL control companies operating above 30 PSI in a basic commercial installation.
I have ran across loads of devices in central heating / chiller plants operating above 30 PSI but those are not what you would call NORMAL applications as what my post was about.
The 30 / 20 PSI was a basic reference to a TYPICAL pneumatic system , I have systems that are 100 PSI + on the Mains and stepped down to required range throughout a 185,000 sq foot 1 storey building and others that have a 30 PSI main that supplies a 24 storey building.
A typical BARBER COLMAN 6" 3 way valve will close off against 125 PSI Water with an actuator that takes 10 PSI , and yet a 2 way 6" will only close off against 21 PSI with a 20 PSI actuator , so you see not everything is TYPICAL
I was refering to ur previous reply stating "nearly 30 years pneumatic experience" So u started the whole "childish" thing. Also no one said anything about typical, cause whats typical for one may not be typical for another.............Im done arguing with u!!!