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A.0500.251 – IM-TL/13.00 EN (08/2009)
12.2.6 Setting and operating – Air loaded - air lifted safety relief valves
To adjust the set-pressure of valve do as follows:
• Make sure that the pressure in the control pressure cylinder and the air lift chamber
is completely relieved.
• Connect the pressure gauge to the discharge line and open the discharge valve
completely
• Start the pump
• Operate the adjusting valve to slowly increase the control pressure of the valve until
the maximum control pressure is reached. While doing this check that the discharge
pressure is not rising above the maximum allowable pressure
of the pump
• Close the discharge valve slowly until the
desired set pressure is reached
• Operate the adjusting
valve slowly to
decrease the control pressure of the valve
until the discharge pressure is starting to
drop away
• Check the proper setting of the valve by
slowly opening and closing the discharge
valve. The set-pressure of the relief valve
can be increased by increasing the control pressure and decreased by decreasing the
control pressure
• After setting the relief valve, open the discharge valve completely
If the valve is not adjusted according to the method described above the correct valve
setting cannot be guaranteed and the pump might be damaged because of too high
discharge pressure.
If there is no possibility to connect a pressure gauge in the discharge line or there is no
discharge valve foreseen in the installation, the valve setting might be approached by
adjusting the control pressure to the values indicated in the table below.
Pressure gauge
Valve