Gas-Ballast; Figure 1 General View Of The Pump - Edwards E2M28 Instruction Manual

Figure 1 General view of the pump

1. Oil filler 1. Oil filler
3. Gas-ballast control 3. Gas-ballast control
5. Centring-ring and O-ring (supplied) 5. Centring-ring and O-ring (supplied)
7. Cable-gland/Amphenol connector 7. Cable-gland/Amphenol connector
position position
10. Box section skids 10. Box section skids
12. Oil sight-glass 12. Oil sight-glass
14. Oil drip tray 14. Oil drip tray
Note:
A pump with a single-phase motor is shown in this figure. The motor shown in this figure
is not representative of the motor used on the E2M28 (Amphenol) pump with item
number A37317984. On this pump, cable-gland/amphenol connector position and on/off
switch are transposed, with cable-gland/amphenol connector position being an
IEC60320 16-20 Amp socket.

2.4 Gas-ballast

To pump high vapour loads, gas-ballast is delivered into the pump to prevent
condensation of the vapour carried by the pumped gases.
Air (or another gas) can be introduced into the low vacuum stage through the gas-ballast
control. The gas-ballast control is a multi-turn valve which can be adjusted, as required,
between closed and fully open.
A37310880_V - Introduction
11. Oil drain-plug (gravity drain) 11. Oil drain-plug (gravity drain)
13. Pump identification label 13. Pump identification label
Page 11
2. Outlet nozzle 2. Outlet nozzle
4. Gas-ballast inlet 4. Gas-ballast inlet
6. Inlet-port (adaptor flange) 6. Inlet-port (adaptor flange)
8. Motor terminal box 8. Motor terminal box
9. On/Off switch 9. On/Off switch