Unloading Valve - PEDRO GIL 454025 Manual De Instrucciones

Salvador Albert I Riera, 9 – Pol.Ind. Vallmorena
Tel. (34) 93 753 71 71 – Fax(34) 93 753 73 00
e-mail: ventas@pedrogil.com
08339 VILASSAR DE DALT (Barcelona) España

13- UNLOADING VALVE

General observations:
The PG unloading valve 'vents' air produced at the time of starting up the blower. This prevents an overload situation
occurring due to the blower starting against a fixed load as in the case of water treatment applications, allowing a gradual
start-up of the blower.
Installation:
The unloading valve must be installed between the discharge silencer and the anti-return valve, as shown in the diagram:
Operation:
When the blower is stopped, the valve is open. On starting the blower, the air is let out through the pipe (A) and
simultaneously the air passes through the pipe (pos. 9) of the valve. This gives rise to a dynamic pressure that acts on the
upper space of the membrane (pos. 6) compressing the membrane and the valve is closed.
The valve reaction time is regulated by means of the screw (pos. 11) in such a way that the greater the dynamic pressure,
the more quickly the valve closes. Once the dynamic pressure has been regulated, the nut must be tightened (pos. 10) to
allow the system, thereby preventing any change in that pressure.
Unloading
valve
37