A371–22–880 Issue R
Page 4
© Edwards Limited 2013. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Introduction
1.3
Description
The Edwards E2M0.7 and E2M1.5 pump is shown in
for item numbers in brackets in the
following descriptions.
The E2M0.7 and E2M1.5 pumps are two-stage, direct drive, sliding vane pumps. The pump is oil-sealed and designed
for reliable, long-term operation. The pump is a free-standing unit. The drive is provided through a coupling by a
single-phase motor.
The motor is totally enclosed and is cooled by the motor-cooling fan which directs air along the motor fins. The
motors are fitted with a thermal overload device. When the motor is too hot, the thermal overload device switches
off the pump. The thermal overload device has an automatic reset; when the motor cools down, the device resets
and the motor will restart.
An oil pressure system lubricates the pump shaft bearing surfaces and rotor sealing faces. The pump has an oil
distribution valve which prevents discharge of oil to the pump interior (suckback) after the pump stops. The pumping
chambers are air-tight, so this arrangement prevents oil suckback unless the gas-ballast valve is open. For protection
in this case, refer to
The level and condition of the oil in the oil box reservoir can be inspected through the sight-glass (9). An oil filler-
plug (6) is fitted to the top of the oil box. An oil drain-plug (11) is fitted at the bottom of the oil box.
The pump has a carrying handle (3), inlet-port (4), outlet nozzle (7) and gas-ballast control (5). The pump is mounted
on a steel baseplate (12) on rubber pads. Details of suitable vibration isolators and other recommended accessories
are given in
1.4
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 that can be adjusted, as required, between closed and fully open.