DP Pumps Hydro-Unit Premium, Инструкция по установке и эксплуатации

Страница: 48 / 96

48 / 96
6. Check the automatic switching functionality.
7. Check the start and stop points of the pressure booster system.
8. Check the water inflow, lack-of-water monitoring and pressure reducer.
8.2.3 Maintenance schedule
Table 20: Overview of maintenance work
Maintenance interval Servicing/maintenance work
At least once a year Check the pump sets for smooth running and the mechanical seal for integrity.
Check the shut-off elements, drain valves and check valves for proper functioning and
tightness.
If fitted, clean the strainer in the pressure reducer.
If fitted, check the expansion joints for any wear.
Verify the pre-charge pressure. Check the accumulator for integrity.
[
ð
Section 8.2.4, Page 48]
Check the automatic switching functionality.
Check the cut-in levels and cut-out levels.
Check the inflow, inlet pressure, dry running protection, flow monitoring and pressure reducer.
8.2.4 Setting the pre-charge pressure
WARNING
Wrong gas
Danger of poisoning!
Ø
Use only nitrogen to charge the accumulator.
CAUTION
Pre-charge pressure too high
Damage to the accumulator!
Ø Observe the manufacturer's product literature (see name plate or operating
manual of the accumulator).
The accumulator ’s pre-charge pressure (p) must be lower than the set start-up pressure (p
E
)
of the pressure booster system.
The best storage volumes are achieved with the following settings (mean value):
– Value 0.9 at start-up pressure > 3 bar
– Value 0.8 at start-up pressure < 3 bar
Example 1
p
E
= 5 bar
5 bar × 0.9 = 4.5 bar
With a start-up pressure of 5 bar the pre-charge pressure of the accumulator must be 4.5
bar.
Example 2
p
E
= 2 bar
2 bar × 0.8 = 1.6 bar
With a start-up pressure of 2 bar the pre-charge pressure of the accumulator must be 1.6
bar.
Checking the pre-charge pressure
1. Close the shut-off elements fitted underneath the membrane-type accumulator.
2. Drain the membrane-type accumulator via the drain valve.
3. Remove and store the protective cap of the membrane-type accumulator valve.