Coalescing Oil Return Line Setup - Emerson Vilter VSS Installation, Operation & Maintenance Manual

Section 4 • Operation

Coalescing Oil Return Line Setup

Over time, oil will accumulate on the coalescing side
of the oil separator. As a result, an oil return line with a
shut-off valve, sight-glass, check valve and needle valve
are installed between the coalescing side and compres-
sor to return this oil back to the compressor.
To adjust the return flow, proceed with the follow
procedure:
Do not fully open the needle valve unless directed by
Vilter Technical Support. Leaving the needle valve
TM
fully open will reduce efficiency of the compressor unit.
1. Open shut-off valve on coalescing side of oil separa-
tor, see Figure 4-13.
4 – 16
NOTE
Coalescing Oil Return Line
Figure 4-13. Coalescing Oil Return Line
VSS/VSM/VSH/VSSH • Installation, Operation and Maintenance Manual • Emerson • 35391SD
2. While the unit is in operation, crack open needle
valve and observe oil flow through sight-glass.
3. Slowly open needle valve more until a small amount
of oil is seen in the sight-glass.
The sight-glass should never be full with oil.
4. Periodically check oil in the sight-glass and ensure
that there is flow.
NOTE
Needle
Valve
Check
Valve
Sight-
Glass
Shut-Off
Valve