7.2 PONYBENCH BPPLUS PNEUMATIC-HYDRAULIC DIAGRAM
The operating diagram of the PONYBENCH BPPLUS pneumatic system is composed as follows:
�
��
1.
Pneumatic-hydraulic pump
�
2.
Single-acting jack for lift control
3.
Lift ascent pneumatic control valve
�
4.
Lift descent pneumatic control valve
�
5.
Check valve
6.
Unidirectional valve
7.
Pressure relief valve
8.
Oil fi lter
9.
Pump casing
10. Air silencer
11. Pneumatic-hydraulic pump oil tank
12. Descent control valve
13. Compressed air intake
14. Safety lock valve (against pipe breakage)
•
OPERATION
By enabling the ascent control, the pneumatic-hydraulic
pump (9) rotates andthe oil under pressure passes through
the safety valve (14) and is then conveyed to the plunger
chamber of the jack, thus raising the movable platform.
When the lift must be lowered, the monostable 3/2 valve
(4) is energised and connects the air duct to the outlet,
permitting the oil to fl ow to the tank (11). The fl ow control
valve (12) controls the fl ow of oil from the jack thus keeping
the descent speed within the limits provided for by the
manufacturer.
The main pressure relief valve (7) prevents the pressure
from exceeding the value established by the manufacturer.
The main pressure relief valve (7) must not be tampered
with for any reason:
WARNING! Alteration of the relief valve will
seriously damage the PONYBENCH BPPLUS.
SPANESI S.p.A. declines all responsibility for
injury to persons and animals or damage to
property due to alteration of this valve.
81
GB