18
5.4
Depress the steering ring slightly, release the safety latch
and allow the tank assembly to rise
under hand restraint.
5.5
Try the balance of the load and adjust the pressure if necessary.
5.6
If the load is to remain static at a fixed height for any length of time, engage the top clamp
.
Adjusting pressure
6
The pressure in the pneumatic system may be increased or decreased to provide the correct
counterbalancing force as follows:
6.1
To increase pressure, remove the load and pressurize the pedestal.
6.2
To reduce the pressure, set the control valve
) until the
desired force is achieved, then set it to the WORK position.
Removing a load
7
To remove a load proceed as follows:
7.1
Depress the top stage to its lowest point and engage the safety latch
7.2
Engage the top clamp
and remove the load.
7.3
Unless another load is to be fitted, depressurize the pedestal by setting the control valve
to
the BLEED position (
).
7.4
After depressurization set the control valve to the WORK position.
Using the pedestal
Height adjustment
Lower stage
8
The elevation tube
forms the lower stage of the pedestal height adjustment and has a range of
431 mm (16.9 in.). This stage is not fitted with any form of counterbalance mechanism but has been designed
so that the piston effect of the elevation tube entering the outer tube will provide sufficient air-damping to
prevent a sudden drop if the lower clamp is released while the pedestal is carrying a load.
9
To adjust the height setting:
9.1
Lower the top stage and engage the top clamp
.
9.2
Support the weight of the load by holding the steering ring
and then slacken the bottom clamp
by turning the knob counter-clockwise until the lower stage is free to move.
9.3
Use the steering ring to set the column at the required height and tighten the bottom clamp.
