American Dryer Corp. AD-100 - Manual (Page 55)

SUGGESTED STEAM COIL PIPING ARRANGMENT
FIG . 1
Care must be exercised when leveling steam dryers in final position. After level­
ing the dryer, check the downward pitch of the heat exchanger from front to rear
with a level. Likewise, check the downward pitch of the return condensate manifold
toward its outlet port. Absence of these downward pitches will result in
probable water hammer and premature heat exchanger fracture and leakage.
The heat exchanger coils are designed to operate with dry steam only. The presence
of condensate in the steam will cause water hammer and subsequent heaL exchanger
failure. The steam supply connection must be taken from the top of a well dripped
steam main. If the supply run-out to the dryer exceeds twenty feet, it should be
dripped just before the control valve with a proper trap and a dirt pocket. (See
Figure 1)
Proper trap selection is mandatory. For low pressure units (15 psi or less) use
an F & T (float and thermostatic) trap. For pressures above 15 psi up to 125 psi
use bucket (inverted bucket) traps. DO NOT EXCEED 125 psi. Do not use thermo­
dynamic, disc, or impulse traps.
Condensate disposal is important. Do not elevate the condensate return line
after an F & T trap. Drain only by gravity into a properly-vented low pressure
return or condensate tank. A condensate line may be elevated after a bucket trap
only if there is sufficient pressure to overcome the head. Determine steam
pressure after deducting 12 psi for the control valve, coil, and trap losses.
(Each foot of elevation requires 1/2 pound of remaining pressure.)
Trap location is essential. The trap inlet should be positioned 12" minimum below
coil outlet to assure complete coil drainage.
10-7