Design and operation
The pumping unit is composed of a cylinder (1), rotor with vanes (2), two end plates with bearings (3) as well as an inlet connecting port with a cut-off valve (4). The pumping unit is connected to the separator via the outlet of the cylinder (5). The oil separator is designed as aluminium casting in the form of a double-chamber box. The lower chamber serves as an oil container, where operating oil and oil filters are located. The upper part of it is fitted with outlet filters (oil mist filters).

The torque from the electric motor is transmitted via a claw coupling (6). Three-phase or single-phase electric motors were used as a drive for pumps. Thanks to the pump being fitted with a gas ballast, it is possible to pump the air containing water vapours.
 
A safety anti-suckback valve in the inlet flange shuts off the inlet line automatically and prevents the operating oil back-streaming when the pump is switched off. The lubricating system works in a closed cycle. Oil hold by outlet filters returns automatically to this system. Pumps are cooled with air.     

Appropriation and operation mode
The AT pumps are designed for operation at the ambient temperatures of 5 to 300C. The pumps are fitted with a very effective separation system, which separates oil mist from the outlet air. Thanks to this feature they do not pollute the environment with oil mist. They can be used for pumping pure air or other inert gases. When equipped with a WF filter, air with dust or solid particles can be pumped as well.
 
AT6B, AT10B, AT21B, AT40 - oil returns during pump operation, continous or intermittent operation possible in the range of pressures: 2 ÷ 400 hPa.
AT21 - oil returns during standstill, only intermittent operation possible in the range of pressures: 2 ÷ 1000 hPa.
AT21A - oil returns during pump operation, continous or intermittent operation possible in the range of pressures: 2 ÷ 1000 hPa.
AT63B, AT100B, AT160B, AT250B, AT400B, AT630B - oil returns during pump operation through float valve, continous or intermittent operation possible in the range of pressures: 1 ÷ 600 hPa.
 
Admissible frequency of pump starts:
AT6B ÷ AT100B - no more than 1 start in a minute
AT21 - 1 ÷ 15 minutes operation, 1 minute break
AT160B ÷ AT630B - no more than 1 start in 10 minutes
Detail information about pump installation and operation can be found in applicable instructions manual.

Application

• meat and cured meat products processing appliances
• meat fragmenting appliances
• can-closing systems
• clipping machines
• central vacuum installations
• suction-transportation appliances
• load lifting devices
• partial vacuum sewage systems
• appliances for degassing, filtering off and filtering
• vacuum chambers for disinfecting
• oil and other fluid filtering off appliances to working machines, cars etc.
• chambers to be used for tests in aviation
• vacuum packing machines
• packing lines
• packages forming appliances
• appliances for degassing and vacuum drying
• in education for demonstration of phisical phenomena in vacuum enviroment

Operation features

• reliable operation in the whole range of fore vacuum
• direct drive
• clean outlet air
• silent operation and low vibration
• built in cut-off valve
• air cooling
• possible to adjust to various types of power supply

Options
Vacuum pumps AT63B, 100B, 160B, 250B, 400B, 630B have to be secured extra with additional elements as follows:

• oil level sensor FTL260/19 - 253 V AC
• oil temperature sensor TP-492 Pt 100-1-50
• oil separator pressure sensor DMM/N/2/F/3/1 - thread M10x1 (NC)
• bimetallic thermostat (NC) no 7.34006.440-100÷ 89^oC

Description
Letters and digits in a pump mean:
- AT - vacuum sliding-vane pump, single-stage oil pump for fore vacuum
- 6, 21, 40, 63, 100, 160, 250, 400, 630 - nominal pumping speed in m3/h
- A, B - constructional types of pumps