5
GENERAL INSTALLATION CONSIDERATIONS
For the condensate to properly enter the drain reservoir, the
condensate line to the drain must always be installed below the
bottom of the vessel to be drained. It is equally important to provide
a means for the air that is contained in the reservoir to escape
(balance line) as the condensate enters the reservoir. If the air
cannot escape, the condensate will not enter the reservoir. Below
are suggestions on how to best install the drain on typical types of
vessels that have to drained of condensate. However, it is possible
to install the drain without a balance line (Dwg. not shown),
providing the condensate enters the top inlet and the flow rates are
less than 9 GPH (750 SCFM for an aftercooler or 1,500 SCFM
dryer) for a 1/2" drain line and 19 GPH (1,500 cfm for an aftercooler
or 3,000 SCFM dryer) for a 3/4" line. The use of unions and shut-off
valves are recommended for both the condensate line and the
balance line.
RECEIVER TANK
The preferred installation for this drain on a receiver tank is having
the condensate enter the top inlet port and having the balance line
go back to the tank at a position that is above the level of the
condensate. (See Dwg. 1).
FILTER and AFTERCOOLER MOISTURE SEPARATOR
If a cyclone separator or filter has pipe plugs located in the top of
the head, the plug closest to the discharge pipe should be removed
and the balance line should be installed (Dwg. 2). If there is no
provision on the cyclone separator or filter for a balance line, install
it in the discharge side of the pipeline and as close to the cyclone
separator as possible.
REFRIGERATED DRYER
If a balance line is required, it must be connected to the port located
on top of the separator that is closest to the discharge side (Dwg.
2), or between the separator and the air-to-air heat exchanger. If a
port is not available as described above, then venting to
atmosphere is recommended. When venting to atmosphere, the
condensate should enter through the bottom entry port on the drain.
The bleed or needle valve is installed on the 1/8" NPT vent port and
allows the air in the drain reservoir to escape to the atmosphere
(Dwg 3). The bleed valve (not included) should be adjusted so that
only 3 to 5 bubbles per second are visible. It is not recommended
to install a vent line downstream from the dryer. The vent line can
be a conduit for transferring moisture from the drain to the
previously dried air. This can result in unwanted moisture being sent
down stream.
INTERCOOLERS
Install the condensate drain line into the upper port only. This will
prevent the possibility of condensate being drawn back into the
intercooler on some systems. It is important that the vent line be
installed on the same stage that is being drained or to atmosphere.
BALANCE LINE
As mentioned above, both the use and the placement of a balance
line is very important. Most drain failures are the result of an
improper balance line installation. The balance line should be 1/4"
tubing or larger, and installed on top of a pipe or vessel, not the
bottom. A needle valve is recommended for controlling the air flow.
Avoid having any loops or low areas in the balance line that might
allow moisture to collect in the line and prevent the passage of air
from the drain’s reservoir.
DWG 1.
DWG 3.
DWG 2.
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