Maytag MD-170, Installation & Operator'S Manual

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30
STEAM DAMPER SYSTEM
a. The pressure of the condensate in the steam supply will cause water hammer and subsequent heat
exchanger (steam coil) failure. The steam supply connection into the main supply line must be made
within a minimum 12-inch riser. This will prevent any condensate from draining towards the dryer.
b. The steam supply piping to the dryer must include a 12-inch rise along with a drip trap and check valve.
This will prevent any condensate from entering the steam coil.
c. Flexible hoses or couplings must be used. The dryer vibrates slightly when it runs and this will cause the
steam coil connections to crack if they are hard piped to the supply and return mains.
d. Shut-off valves for each dryer should be installed in the supply, return, and drip trap return lines. This will
allow the dryer to be isolated from the supply and return mains if the dryer needs maintenance work.
e. Install an inverted bucket steam trap and check valve for each unit at least 12-inches below steam coil as
close to the coil as possible.
1) An inverted bucket steam trap with capacity of 1,400 pounds of condensate per hour @ 125 PSI is
required for each dryer.
f. A 3/4" vacuum breaker should be installed. This will save energy and provide for safety of the operator
and maintenance personnel.
g. The supply and return lines should be insulated. This will save energy and provide for safety of the
operator and maintenance personnel.
h. Water pockets in the supply line, caused by low points, will provide wet steam to the coil possibly causing
coil damage. ALL horizontal runs of steam supply piping should be pitched 1/4-inch for every one (1)
foot back towards the steam supply header causing any condensate in the line to drain to the
header. Install a bypass trap in any low point to eliminate wet steam.