P2.x ATEX
6.2 Inspecting the bellow
NOTICE
When following preventive maintenance according to the maintenance plan, a crack in
the bellows is a rare malfunction, but cannot be completely eliminated.
NOTICE
If the bellow cracked, turn the pump off immediately!
NOTICE
If flammable gases (even above upper explosion limit (UEL)) or toxic gases are supplied,
continuous monitoring of the pump is mandatory.
DANGER
Explosion hazard, danger of poisoning!
A crack in the bellows when conveying flammable or poisonous gasses may allow explos-
ive or poisonous gas mixtures to leak or develop.
Monitor the pump with a flow- and/or vacuum monitoring system (see flow diagram).
If a pump defect occurs, shut it off immediately.
Since a crack
in the bellow allows
the ambient atmosphere to be sucked in and the sample gas pump continues to generate
pressure,
the bellow on the sample gas pump must be inspected regularly
.
This is done by connecting a suitable shut-off unit and a suitable vacuum pressure gauge ahead of the sample gas input (see il-
lustration). If during operation, after closing the suction line, no negative pressure is produced, the bellows is defective and
must be replaced.
[> page 20] for maintenance intervals.
Fig. 2: Inspecting the bellow
21
Bühler Technologies GmbH
BE420002 ◦ 07/2022
