December 2020
Installation, Operation and Maintenance Manual
MAN 606 Rev. 5
Operation and Use
1
2
3
4
D
P
R
O
18
Section 3: Operation and Use
3.3.2
Emergency Manual Operation by MHP
The OLGA actuators can have an emergency manual override in addition to the local
and/or remote control panel which controls the oil supplied by a power pack for the
“normal” actuator operation. The emergency manual override, mounted on the actuator,
consists of a hydraulic manual override and a hydraulic manual selector to choose
actuator “Normal operation” with oil supply from a power pack, or the “Emergency
manual operation”.
The compact hydraulic override consist of:
•
handpump
•
directional control valve to select the “to open” or “to close” operation by
handpump
•
relief valve to prevent the oil pressure delivered by the handpump from exceeding
the maximum allowable value
On request the emergency manual override can be included in the power pack.
Figure 15
Hydraulic
connections
to the hydraulic
control panel
(to close)
(to open)
Table 5.
Item
Name
1
Scotch yoke mechanism
2
Hydraulic cylinder
3
Hydraulic manual override
4
Hydraulic manual selector
D
Directional control valve
P
Handpump
R
Relief valve
O
Oil tank
