Grundfos PLV Series, Installation And Operating Instructions Manual

Page: 10 / 16

English (GB)
10
5. Settings
The opening pressure can only be set, if a pressure gauge is
installed in the system between the pump and the pressure
loading valve.
The opening pressure of the valve is set in the factory to the
value specified in the technical data. During operation, the
opening pressure depends on various factors, e.g. the flow, the
stroke frequency of the pump, or the counterpressure. If a more
precise setting is required, the valve must be adapted to the local
conditions.
5.1 Setting the opening pressure
Fig. 13
Setting the opening pressure
While the pump is running:
1. Remove the protective cap from the top part of the valve.
2. Read the current opening pressure on the pressure gauge
installed in front of the pressure loading valve.
3. For valves up to 60 l/h use a hexagon wrench (A), for DN 20 to
DN 65 use a pair of needle-nosed pliers (B):
– turn adjustment screw (C) clockwise to increase the
pressure
– turn adjustment screw (C) counterclockwise to reduce the
pressure
4. Set the desired opening pressure.
5. Attach the protective cap again.
6. Maintenance
6.1 Intervals for cleaning and maintenance
• At least every 12 months or after 8000 operating hours
• If faults occur.
Clean the valve, and replace the diaphragm and O-rings,
if necessary.
6.2 Replacing the diaphragm
For spare parts see section
8. Spare parts and accessories
.
1. Shut down dosing system.
2. Make it impossible for a return flow or overpressure to occur.
3. Loosen screws on top part of valve.
4. Remove top part of valve.
5. Remove diaphragm.
6. Insert new diaphragm.
7. Refit top part of valve and tighten screws diagonally.
Max. torque:
8. Start up dosing system again.
9. Re-tighten screws on top part of valve after 48 operating
hours. Max. torque:
Warning
Settings on the valve must only be carried out by
authorized personnel!
Warning
Danger of injury! Never set the opening pressure
higher than the maximum permissible operating
pressure of dosing system and dosing pump!
T
M
04
83
37
05
11
A
B
C
Warning
When working on the product, or connections
and lines, always wear protective clothing
(e.g. safety goggles and gloves)!
The system must be unpressurised!
Only operate the system if all lines are connected
correctly!
Up to 60 l/h DN 20, DN 32 DN 50, DN 65
2 Nm 5 Nm 5 Nm
Up to 60 l/h DN 20, DN 32 DN 50, DN 65
2 Nm 5 Nm 5 Nm