Copyright 2022 Baker Hughes Company.
English–DPI 610E Instruction Manual | 33
Pneumatic System
2.1.7.2 Creating a High Vacuum (-950 mbarg)
Follow these instructions to achieve a high vacuum:
1.
Turn the pressure/vacuum selector collar to the vacuum ‘-’ position. Note that as the vacuum
increases, it is only the last part of the pump travel (i.e. fully pulled-out) that actually
increases the vacuum. This is exactly similar to pumping positive pressure, where it is only
the last part of the inward travel that pushes air past the non-return valve as pressure rises.
Therefore, for effective use, the pump must be fully pulled out (until the end stop is felt) to
effectively generate vacuum.
2.
It is much more effective to pull the pump knob out quite quickly (until end stop is hit)
because this keeps the non-return valve fully open.
3.
To try to get to -950 mbar is similar to trying to remove 95% of the air from the system: this
requires approximately 15-20 (fast) strokes to achieve.
4.
If difficulty is still encountered getting to low vacuum then stop pumping and use the volume
adjuster – unscrewing this will draw further vacuum and reduce the pressure.
5.
If -950 mbar is achieved but then the pressure slowly increases (i.e. system appears to be
leaking) then check that the relief valve is tightly shut and the IDT (Instrument Dirt Trap)
top/bottom seals are not leaking.
