3. Maintenance and troubleshooting
MERMAID E500-S
STD08
Page 30 of 52
•
Setting and servicing the un-loader/safety valve assembly
The un-loader and safety valve must be reset correctly by a trained personal after repair or
inspection.
The working pressure will decrease as the nozzle wears.
When servicing of the machine, ensure that the machine is cool down. Disconnect the machine
from the main electrical source before attempt to service the machine.
The un-loader and safety valve must be reset correctly after repair or inspection
The working pressure will decrease as the nozzle wears.
(Please refer to Un-loader Assy,
Pg 38~39
and Safety Valve Assy,
Pg 40~41
)
•
Setting of un-loader/safety valve
The pressure setting must be done with the system running and spray gun opened.
To produce a pressure increase, simply turn the regulation screw/knob screwing it (unscrewing for
a decrease).
If, before reaching the desired pressure, screwing the screw/knob doesn’t occur any more pressure
increase: check if the nozzle is worn out or correct size (refer to part list pg. 42)
ADJUSTMENT OF THE UNLOADER VALVE’S MAXIMUM
PRESSURE
: Acting on the adjustment knob increase the pressure until you reach the desired
value (with the gun opened). Repeat some operations of closing and opening of the high pressure
water spray gun and then check (always with the gun opened) that the set pressure is really the one
wanted. Once the pressure is regulated:
· switch off the system;
· unscrew the ring nut to the highest position (up to the brass knob);
· block the ring nut by tightening the stop dowel.
For a correct and lasting use of the valve ensure that, with the pressure adjustment occurred, at
least 5% of the water flow provided by the pump is regularly discharged through the by-pass. The
maximum pressure set in this way could still need some fine tuning adjustments, consequently
always make sure the adjustment matches that required.
•
Torque specification
Valve Cover Bolts
............................................................. 50 Nm (5.0 kgm) (37 lbs.ft)
Piston Nut
............................................................... 15 Nm (1.5 kgm) (11 lbs.ft)
Connecting Rod Screws ............................................................... 30 Nm (3.0 kgm) (22 lbs.ft)
Incorrect setting of the Unloader / Safety valve will damage or
endanger the user. Therefore, a trained personal must perform
the setting to ensure the machine is working correctly.
WARNING
