Note:
Automatic: Open service valves completely to keep coalescer end of separator free of
oil. The sight glass in the valve indicates flow variations.
Note:
Normal operating oil level is halfway in the top sight glass, which is located midway
along the oil separator shell.
Automatic oil return valve
Figure 20: Automatic oil return valve
1
Inlet G1/4 in.
2
Filter
3
Stop valve, inlet side
4
Stop valve, outlet side
5
Outlet G1/4 in.
6
Sight glass
Note:
The valve inlet and outlet are marked on the valve housing with "in" and “out”.
Function
The function of the automatic oil return valve, EVRB, is to return the separated oil in the fine
separator to the compressor.
Oil and gas from the fine separator flow into the oil return valve at position 1, through the filter,
position 2, and through the nozzles, position 7 and 8, and back to the compressor through the
.
The gas and oil flow through the nozzles, position 7 and 8, is adapted to the spring force of position
9 as well as the viscosity difference between the oil and the gas. Consequently, the pressure loss of
the gas flow through the nozzle, position 7, is unable to move the piston, position 7.
However,the pressure loss of the oil flow through the nozzle, position 7, is able to move the piston,
position 7.
SAB 283-355 A-Frame OHU 6042 and OHU 7650 (including ATEX) Screw Compressor Unit
48
