Setting The Opening Pressure Of The Integral Relief Valve - Grundfos DMX 221 Installations- Und Bedienungsanleitung

3.10 Setting the opening pressure of the integral relief valve

• Make sure a pressure gauge is installed between the pump and an isolating valve in the out-
let line.
• Make sure the pump was installed and started up correctly.
• Make sure the pump is running during this task.
Fig. 3.10-1 Setting the opening pressure of the relief valve using a pair of pointed pliers
1. Remove the cap from the relief valve.
2. Close the isolating valve.
3. When the relief valve opens, read the pressure on the pressure gauge.
4. Set the opening pressure of the relief valve:
• To increase the opening pressure, turn the knob clockwise using a pair of pointed pli-
ers until the desired pressure is reached. Do not set the opening pressure higher than
the maximum counterpressure of the pump.
• To reduce the opening pressure, turn the knob counter-clockwise using a pair of poin-
ted pliers until the desired pressure is reached.
5. Open the isolating valve.
6. Refit the cap.
Related information
• 3.1 Preparing the pump for startup
• 3.3 Starting up the pump
WARNING
Chemical hazard
Death or serious personal injury
● Do not set the opening pressure higher than the maximum counterpressure of
the pump.
● Wear protective clothing when working on the dosing head, connections or
lines.
● Collect and dispose of all chemicals in a way that is not harmful to persons or
the environment.
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