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2.
Mode of operation
As a rule, the pump may be operated in any position but the longest service life of
sealings is ensured when it is installed vertically.
2.1
Drive part
The drive part consists of an air cylinder (22), bottom cap (20), top cap (26) and
air piston (48) to which compressed air is admitted reciprocally that prompts it to
make an oscillating motion.
In its stop positions the air piston (48) actuates the pilot valve plungers (53,85).
These pilot valves control the servovalve (31) by means of compressed air.
The pump is driven with compressed air (other gases upon request). When
compressed air is employed as drive we recommend our maintenance unit,
consisting of a filter, water separator, shut-off valve, pressure controller and
master pressure gauge.
If the maintenance unit is not installed, a suitable filter with a 5
µ
m mesh should
be used.
A lubrificator is not required since the pump is treated with a high-performance
grease prior to shipment.
If a lubrificator is provided in the drive system, a silicon- and acid-free oil should
be used to avoid swelling of packing rings. A pump that is equipped with a
lubrificator may only be used in lubrificator-equipped systems.
2.2
Control part
The control part consists of the servovalve (31), and servovalve runner (35), all
accommodated in the servovalve casing (83).
The servovalve (31) is actuated with compressed air by the pilot valves (53,85). The
servovalve feeds drive air to the right or left side of the air drive piston (48).