Steam Damper System

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-inches (30.48 cm) below steam coil, as close to the coil as possible; a trap with a capacity of 1,200 lb (544 kg) of condensate per hour at 125 psi (8.61 bar) 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.Dryers with optional solenoid valve must be mounted with coil positioned directly above the valve body.

h.The supply and return lines should be insulated. This will save energy and provide safety for the operator and maintenance personnel.

i.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.

4.Steam Damper Air System Connections

The dryer is manufactured with a pneumatic (piston) damper system, which requires an external supply of compressed air. The air connection is made to the steam damper solenoid valve, which is located at the rear inner top area of the dryer just above the electric service relay box.

a. Air Requirements

Compressed Air Supply	Air Pressure
Normal	80 psi	5.51 bar
Minimum Supply	70 psi	4.82 bar
Maximum Supply	90 psi	6.21 bar

Shaded areas are stated in metric equivalents

American Dryer Corp.

113202 - 10

STEAM DAMPER SYSTEM

Compressed Air Supply

Air Pressure

6.21 bar

American Dryer Corp.