SABROE SAB 233 S User Manual

Engineering manual - SAB 193-233-283 S A-frame (including ATEX)
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008831 en 2022.02
Technical description
4.15 Unit with double oil filter
If the unit is equipped with two parallel oil filters, only one filter at a time must be in operation.
The filter not in use can be cleaned when the compressor is in operation.
When cleaning the oil filter during operation, please note that the pressure is higher when the
vent valve/plug is opened. Especially in connection with HFC/HCFC plants, there may be a lot
of oil foam.
Note: During operation, at least one or both discharge valve(s) must be open to avoid hydraul-
ic pressure in the filter housing.
4.16 Compressor hydraulic system
The compressor hydraulic system moves the movable slide valve (MSV) to load and unload
the compressor, See Fig. 25 and Fig. 26. It also moves the movable slide stop (MSS) to in-
crease or decrease the compressor’s volume ratio (Vi).
The hydraulic cylinder located at the inlet end of the SGC compressor serves a dual purpose.
It is separated by a fixed bulkhead into two sections. The movable slide valve (MSV) section is
to the left of the bulkhead and the movable slide stop (MSS) to the right. Both sections are con-
sidered double-acting hydraulic cylinders as oil pressure moves the pistons in either direction.
Both sections are controlled by double-acting, four-way solenoid valves which are actuated
when a signal from the appropriate microprocessor output energises the solenoid valve. Valves
V1, V2, SC1, SC3 and SC4 are always open.
Single-acting mode, high-stage (T
C
> +15°°C)
• Close the valve at SC2
• Open the valve at BP (by-pass)
High-stage compressor loading
The compressor loads when the MSV solenoid valve, YY2, is energised, and oil flows from the
unloading side of the cylinder out of the port, SC1, through the valve ports, A and T, to the com-
pressor suction side. Simultaneously, the discharge pressure loads the slide valve.
High-stage compressor unloading
The compressor unloads when the MSV solenoid valve, YY1, is energised, and oil flows from
the oil manifold through the valve ports, P and A, to the cylinder port, SC1, and enters the un-
loading side of the cylinder. Simultaneously, gas on the loading side of the cylinder is vented
through the port, SC2, and the valve, BP, to the compressor suction side.
Note: To control the rate of loading and unloading, change cycle time, proportional band and
dead band setpoints with the control system. If additional control is needed, throttle SC2 or BP.
Double-acting mode, booster (T
C
< +15°°C)
• Open the valve at SC2
• Close the valve at BP (by-pass)
Booster compressor loading
The compressor loads when the MSV solenoid valve, YY2, is energised, and oil flows from the
oil manifold through the valve ports, P and B, to the cylinder port, SC2, and enters the loading
side of the cylinder. Simultaneously, oil contained in the unloading side of the cylinder flows out
of cylinder port, SC1, through the valve ports, A and T, to the compressor suction side.
Booster compressor unloading. The compressor unloads when MSV solenoid YY1 is ener-
gised and oil flows from the oil manifold through valve ports P and A to cylinder port SC1 and
enters the unload side of the cylinder. Simultaneously, oil contained in the load side of the

SABROE SAB 233 S Specifications

General

Brand	SABROE
Model	SAB 233 S
Category	Compressor
Language	English