Engineering manual - SAB 193-233-283 S A-frame (including ATEX)
66/168
008831 en 2020.10
Technical description
Fig. 45: Anti-vibration economiser kit
Fig. 46: Anti-vibration Economiser kit
For refrigeration plants employing multiple compressors on a common economising vessel, re-
gardless of economiser type, each compressor must have a back-pressure regulating valve in or-
der to balance the economiser load, or gas flow, between compressors. The problem of balancing
load becomes most important when one or more compressors run at partial load, exposing the
economiser port to suction pressure. In the case of a flash vessel, there is no need for the redun-
dancy of a back-pressure regulating valve on the vessel and each of the multiple compressors.
Omit the BPR valve on the flash economiser vessel and use one on each compressor, as shown in
Fig. 49. It is also recommended that the back-pressure regulating valves, used on economiser
lines, should be specified with electric shutoff option. The electric shutoff feature is necessary to
prevent flow from the common economiser vessel to the suction side of a stopped compressor,
through the suction check valve bypass line, if the other compressors and the common econo-
miser vessel are still operating and the HV2 valve on the suction bypass is open.
For refrigeration plants using a Packaged Refrigerant Recirculation (PRR) unit and a direct expan-
sion (DX) economiser system, it is necessary to operate the liquid feed solenoid on the PRR unit
and the liquid feed solenoid on the DX vessel off of a common signal to avoid liquid overfeed on
the DX economiser system.
If multiple compressors are operated with a common economiser vessel, it is necessary to install
a back-pressure regulator valve with an electric shutoff option in the vapour line piped to the com-
pressor's economiser port. If an electric shut-off is not installed in the economiser vapour line,
valve HV-2 must remain closed to avoid a gas bypass from the economiser line through the suc-
tion check valve bypass, back to the suction line on a compressor that is shut down.
Economiser kit
optional
Strainer
S
hipped loose
Damper
with str
ainer
E
co. line
To Next Page
Loading...
Need help?
General
