Reliable system protection devices

Every pump has protection devices to prevent oil and air suck-back into the vacuum system if the pump stops while under vacuum. A variety of protection devices are used, depending on the pump size and cost, but emphasis is always placed on reliability and simplicity. When you use gas ballast on some of the pumps, you must use a solenoid operated gas ballast control valve to prevent air suck-back.

 

Positive Pressure Oil Lubrication

The EM pumps incorporate a well proven positive pressure oil lubrication system which as been developed by BOC Edwards to ensure correct lubrication in all duty modes and particularly to prevent oil starvation with high gas loads.

 

An integral oil pump ensures that a more than adequate oil flow is pumped throughout the stator/rotor assembly at all times.

 

This oil lubrication system means that the level of oil in the reservoir is less critical than with other pump designs. All pumps can operate with oil levels as low as 50-70% of the maximum. A full length, easily visible oil level sight glass allows you to conveniently monitor the oil level.

 

Gas Ballast Facility

All EM series pumps have a gas ballast valve. The valve is used to introduce a suitable gas into the stator during the compression stage: this prevents condensation of vapors inside the pump, dilutes and ejects corrosive gases and purges the oil of gases and vapors. Therefore, the use of gas ballast reduces oil degradation and pump corrosion.

 

Low Noise Levels

The EM pumps maintain BOC Edwards’s reputation for quiet operation pumps. Pumps up to the E2M1.5 have a typical noise level of 53dB (A), RV pumps 48 to 50dB (A) and the largest pumps have a typical noise level of 75dB (A), all at 1 meter.

 

Pumping Systems

The EM pumps, with suitable accessories, can partner a variety of other types of pump in vacuum systems for industry and for research. A special feature of the larger pumps, from the E1M40 upwards, is their central vacuum inlet which enables you to fit a mechanical booster pump with a minimum overhang, to create compact combination pumping systems.

 

Easy Maintenance

The advanced lubrication system allows the EM pumps to work with wide oil level tolerances, which reduce the need to top-up the oil.

 

All EM pumps are constructed with internal dowels that reduce the need for skilled setting of tolerances when the pump is dismantled. Pumps up to the E2M18 are completely gasket sealed – no sealing lacquer is required. Larger pumps are designed so that all key components are easily accessible. The exhaust valve seals and oil distributor seals are exposed after the top cover is removed. The shaft seal can be replaced quickly without stripping down the pump.