Bühler technologies P2. AMEX Serie Guía Rápida página 14

P2.x AMEX
• Reinstall all parts in the reverse order. Please note the
torque of the hexagon screws (7) is 3 Nm.
Installing the pump head offset by 90° is prohibited!
4.4 Connecting the gas tubes
The pumps are fitted with the connections you have selected
(not pre-assembled for sample gas pumps P2.x AMEX-O2).
Compare the item number on the type plate with the item
number structure in the Introduction.
Avoid mixed-material installation, i.e. piping on plastic bod-
ies. If this cannot be avoided in isolated applications, screw
the metal connections into the PTFE pump body with care,
taking care to avoid use of force.
Lay the lines so that the line at the inlet and outlet remains
flexible for an adequate distance (pump vibrates).
The pumps are marked "In" for inlet and "Out" for outlet. En-
sure that the gas line connections are tight.
With sample gas pumps P2.x AMEX-O2 (item no.: 42.............-
O2), only RT fittings (tapered thread) are supplied by the fact-
ory as separately packaged accessories. These must be fitted
with PTFE sealing tape approved for O applications (see Spare
2
parts and accessories).
4.4.1 Monitoring the sample gas pump
NOTICE
When following preventive maintenance according to the
maintenance plan, a crack in the bellows is a rare malfunc-
tion, 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.
14 Bühler Technologies GmbH
DANGER
Explosion hazard, danger of poisoning!
A crack in the bellows when conveying flammable or poison-
ous gasses may allow explosive 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.
4.4.1.1 General monitoring measures
Since a crack in the bellow allows the ambient atmosphere to
be sucked in and the sample gas pump continues to generate
pressure, the bellows of the sample gas pumps must be in-
spected regularly.
In addition, the flow rate of the pump (to the sample gas out-
let) must be monitored with a suitable flow meter.
For more information or Inspecting the bellow the mainten-
ance schedule, please refer to the chapter Maintenance at the
end of the operating and installation instructions.
4.4.1.2 Monitoring measures when conveying
flammable and/or toxic gasses
Conveying flammable and/or toxic gasses further requires
continuous monitoring of the sample gas pump during oper-
ation. This can be done as follows (1) or (2).
1. Flow rate monitor before the pump's gas inlet and after
the gas outlet. A sudden reduction of the suction
volume / flow volume ahead of the pump and consistent
or suddenly increased flow volume after the pump indic-
ates a defective bellow (the pump can convey ambient air
suctioned in due to the tear).
2. Vacuum monitoring before the pump's gas inlet and flow
monitoring after the gas outlet (see illustration). A sud-
den drop in the vacuum before the gas inlet indicates a
defective bellow.
When conveying flammable gasses above the upper explosive
limit (UEL) we further recommend monitoring the lower ex-
plosive limit (LEL) in the installation location.
When conveying toxic gasses we recommend MAC monitoring
(MAC: Maximum Workplace Concentration) at the installation
site.
underpressure
manometer
shut-off valve
sample gas pump
Fig. 1: Sample flow diagram of suitable monitoring
manometer
flowmeter
BX420003 ◦ 02/2024