Edwards E1M18 Instruction Manual page 14

A34310880_T - Introduction
The E1M18 and E2M18 pumps are direct drive, sliding vane pumps. The E1M18 is a
single-stage pump and the E2M18 is a two-stage pump. The pump is oil-sealed and
designed for reliable, long-term operation in both laboratory and industrial
environments. The pump is a free-standing unit. The drive is provided through a flexible
coupling by a single-phase or three-phase (four pole) motor. The motors are totally
enclosed and are cooled by the motor-cooling fan which directs air along the motor fins.
The single-phase motors have 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. The single phase motors have an on/off switch.
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 air suckback unless the gas-ballast valve is open. For
protection in this case, refer to Gas-ballast on page 11.
The level and condition of oil in the oil box reservoir can be inspected through the oil
sight-glass. An oil filler-plug is fitted to the top of the oil box. The pump has an oil drain-
plug to allow gravity oil drain.
The pump has an inlet-port, outlet nozzle and gas-ballast control. The pump is mounted
on two mild steel box section skids on rubber pads. Details of suitable vibration isolators
and other recommended accessories are given in Accessories on page 46.
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