Flammable And Toxic Gases (Epx N Series Pumps); Start-Up - Edwards EPX HiVac Series Instruction Manual

A419-00-880 Issue F
5.2

Flammable and toxic gases (EPX N series pumps)

The EPX pump should not be used to pump pyrophoric gases or explosive mixtures.
Dilute flammable gases to less than 25% of the LEL (lower explosive limit) before the pump inlet.
The responsibility for ensuring the correct dilution of the pumped gas lies with the operator.
For flammable and toxic gases, the EPX pump must be fitted in an extracted enclosure (not
supplied), and the extract must be monitored. In order for the pump to comply with Semi S2-0200
extracted enclosures are required.
The nitrogen purge flows on the EPX N series of pumps are preset at the factory.
The approximate nitrogen purge flows for a given supply pressure are given in
Flammable gases must be diluted to less than 25% of the LEL. Pyrophoric gases and explosive mixtures should not be
pumped using the EPX pump. The installer must ensure that suitable safety mechanisms are in place to ensure that
dilution is carried out to safe levels.
5.3

Start-up

Do not operate the pump when the exhaust pipeline is restricted or blocked. If you do, the EPX
pump can generate pressures up to 16 bar (1.6 x 10
1. Check the protective earth connection to the pump.
2. Check that the power and control connectors from the pump are connected.
3. Switch on the cooling-water supply and check that there are no leaks. If there are any leaks, switch off the
cooling-water supply, seal the leaks, then switch on the cooling-water supply and check for leaks again. Repeat
this process until the system is leak-tight.
4. Switch on the electrical supply to the EPX pump, and check that the Power LED
Power LED does not go on, refer to
5. Check that the exhaust-extraction system is not restricted, and that any valves in the exhaust-extraction system
are open.
6. Use your control equipment to set the pump run signal to the interface connector (refer to
check that the Run LED
LED does not go on, or if the pump running status output remains open, refer to
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WARNING
WARNING
WARNING
WARNING
Section 6.6.
(Figure 4, item 3) goes on, and that the pump running status output closes. If the Run
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Table 10.
6
Pa) and be damaged.
(Figure 4, item 2) goes on; if the
Section 6.6.
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Section 3.11) and