Festo MPA-S - Page 35

2Overview
Festo – P.BE-MPA-E N – 1309f – English 35
Reversible pressure
regulator
Pressurizing process Exhaust process
Pressure of the supply
air regulate d in front of
the valve 1
Unregulated pressure
of the supply air 2
Exhaust vented via the
pressure regulator
plate 3
Rev. A pressure
regulator
in channel (5) in channel (3) from channel (4)
through channel (1) to
channel (5)
Rev. B pressure
regulator
in channel (3) in channel (5) from c hannel (2)
through channel (1) to
channel (3)
Tab. 2.15 Mode of operation of the reversible A or B pressure regulator
Advantages compared to the A or B pressure regulator:
– Faster cycle times
– 50% higher exhaust flow rate, as air is not e xhausted via the pressure regulator. The load on the
pressure regulator is also reduced.
– No quick exhaust valves are required. The exhaust is ducted completely via the valve terminal.
– Operating pressure is always present at the pressure regulator, as the pressure is regulated up-
stream of the valve. In other words, the regulato r can always be adjusted. With A or B pressure
regulators, the valve must switch.
Disadvantage compared to the A or B pressure regulator:
– Cannot be c ombined with 2x 2/2-way valves with Ident. code D, I and 2x 3/2-way valves with Ident.
code N, K, H (non- reversible valves). These valves r equire working pressure in channel (1) for the
pneumatic spring ( c ircuit symbol in appendix B, Tab. B.4 and Tab. B.3).
Application examples:
– If the air pressure in channel (2) or (4) is not supposed to be the same as the operating pressure of
the valve terminal.
– When fast exhausting is required.
– When the pressure regulator must always be adjustable.