Page Issue 01
Chapter - Water System
10:3
VT551 - Maintenance
RELIEF VALVE
This valve is factory set and should not normally be
touched, but should it be necessary to make adjustments,
the pressure is set as follows.
PRESSURE SETTING
Remove the cover (A) and loosen adjuster locknut (B).
Connect a pressure gauge to the test point located in the
systems locker. With the auxiliary engine running at low
idle speed (750/800), and all water sprays switched off,
turn adjuster screw (C) until gauge reads 3.5 bar (50 psi).
Tighten locknut and replace cover.
SOLENOID VALVES
Solenoid valves control the water spray jets and are
located on the front valance. Each valve incorporates a
filter (A) in its suction port and a manual lift override lever
(B). Turning the lever anticlockwise opens the valve;
clockwise closes it. This manual lift facility can be used
when draining the water system in winter (see Operator’s
Guide, Chapter 3) and for actuating the valve should it for
any reason fail to operate electrically.
The valve is readily dismantled for inspection or cleaning
by unscrewing the retaining cap (C) through the coil (D).
To access the armature, unscrew the four retaining screws
(E) and remove the armature cover (F). The armature (G)
can be removed. When refitting parts ensure the ‘O’ ring
(H) is in good condition and located correctly.
HYDRANT FILTER
Periodically the hydrant filler filter (A) should be cleaned,
or replaced if damaged. To gain access to the filter,
unscrew the hydrant coupling (B) and withdraw the filter
from its housing (C).
95MA
.
021
95MA
.
021
(A)
(A)
(C)
(C)
(B)
(B)
95MA
.
020
95MA
.
020
(C)
(C)
(A)
(A)
(B)
(B)
95MA. 019
95MA. 019
(C)
(C)
(D)
(D)
(B)
(B)
(H)
(H)
(E)
(E)
(F)
(F)
(G)
(G)
(A)
(A)
ON
ON
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