Edwards EDS 300

Free chlorine < 0.2 mg/l
8 °dH (degrees German hardness) = 1.4mmol/l
= 10 °e (degrees English hardness)
= 14 °f (degrees French hardness)
If there is the danger of frost, you may use a water Drystar mixture of up to 50%.
DS water can be used for cooling the pump, if the pH value corresponds to the range indicated
above.
7.5 Connecng purge gas
The pump must be operated with purge gas. The purge gas is distributed in the pump via
ow restrictors as follows:
▪
to the sha-seal on the low vacuum side
▪
into the pumping chamber (balance line)
▪
to the sha-seal on the high vacuum side.
The ow restrictors ensure that the gas ow to the sha-seal on the high vacuum side
becomes very low at ulmate pressure.
The purge gas on the sha-seals provides an air cushion under the sha-seals and thus
prevents premature wear.
Use of the correct sha-seal purge and gas-ballast requirements depend on your applicaon.
If in doubt about your applicaon seng, contact Edwards.
▪ Connect an inert gas supply to the gas system. An upstream supply pressure of 4 to 10
bar(g) is required. Ensure that your gas system can maintain pressure whilst owing up
to 62 SLM of purge gas.
▪ Adjust the regulator on the gas panel to 2.2 bar(g).
▪ The purge supply should be maintained whenever the pump is operaonal, to ensure
the process seals operate correctly and that the oil boxes are adequately protected
from process media.
▪ Be aware that the purge supplies are not automacally controlled, therefore it could be
possible to pressurise the pump or system if purge is le on with a closed system.
▪ Atmospheric gas-ballast can be adjusted or shut o completely, depending on your
applicaon, using the manual needle valve.
WARNING: LEAKAGE OF GAS
The atmospheric sha-seal between the gearbox and atmosphere is a PTFE dynamic seal,
which may, under wear-out condions, lead to small leakage of gearbox gas. Ensure that
purge gas is supplied connuously to the main pump sha-seals to prevent process gas
entering the gearbox which could otherwise leak from the atmospheric sha-seal.
Leakage of purge gas to atmosphere should also be considered; ensure the pump is in a
well venlated area.
Page 29
A41802880_C - Installaon