American Dryer Corp ML-130 II installation manual

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 (30.48 cm) riser. This will prevent any condensate from draining towards the dryer.

b.The steam supply piping to the dryer must include a 12-inch (30.48 cm) 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.Shutoff 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-inch (30.48 cm) below steam coil as close to the coil as possible.

1)A trap with a capacity of 1,200 lbs (544 kg) of condensate per hour at 125 PSI (8.61 bars) is needed for each unit.

f.A 3/4-inch (19.05 mm) vacuum breaker should be installed for each unit in the piping. This will prevent the condensing steam from causing a vacuum inside the coil and possibly damaging the coil.

g.The supply and return lines should be insulated. This will save energy and provide safety for 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 (6.35 mm) for every 1 foot (0.31 meters) 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.

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