AccuTemp EVOLUTION Series Installation & Operator's Manual page 13

Installation Manual I Installation
3.10 Ventilation
DO NOT connect Drain or Vent lines on multiple
appliances. Each appliance should have its own dedicated
drain and vent.
The steam vent is provided with a 45 ° elbow. The steam
vent must not be obstructed. An obstruction will prevent
correct operation of the steamer.
Applicable federal, state and/or local plumbing codes will
dictate when and if a hood is required.
3.10.1 Steam Vent Extension
When adding anything to the vent on the Evolution steamer,
care must be taken to prevent doing anything that puts a back
pressure on the steamer. Back pressure on the steamer may
interfere with the pressure switch that controls the heaters.
When the pressure switch senses pressure in the steamer
that is 0.5" of water column or more, it turns the heaters off.
Therefore, anything on the vent putting a pressure of just 0.5"
water column on the steamer turns the heaters off and prevents
them from coming on again until the pressure is relieved.
Intermittent operation of the steamer can often be traced to
restrictions, low spots or a plugged condensate drain in the vent
fitting assembly.
To prevent putting a back pressure on the steamer, vent piping
should have no restrictions and no low spots where water can
accumulate. Ventilation piping can be directed upwards toward
hoods or downward towards floor drains. Slightly different
approaches are required for each application.
MP4010-1903
Extension Sloping Upward (FIGURE 12)
1. Use nominal ¾" copper, brass or stainless steel to prevent
flow restrictions. Larger inside diameter (ID) can be used also
2. Pipe should slope upward a 1/4" per foot from the steamer
vent toward a vent hood to allow water condensing in it to
run back to the steamer and down the drain line. Minimum
recommended slope is ¼" per foot of hose length.
3. Use rigid pipe rather than flexible tubing or hose to prevent
dips or sags in the pipe that may collect water. A puddle
of water in the piping just ½" deep will cause the steamer
to malfunction. Recommended pipe materials are rigid ¾"
copper tubing (7/8" OD) or brass/ 18-8 stainless steel pipe
(3/4 NPT or larger). Pipe hangers or pipe supports should be
used every six feet to prevent long runs from sagging.
4. A pipe union should be installed next to the steamer to
permit the vent to be easily disconnected. This allows the
steamer to be easily moved for servicing.
5. Total length of extended vent piping should not exceed 15
feet.
FIGURE 12
18" - 36" Long = 3/4" Diam-
eter brass pipe (both ends
threaded)
45 ° Elbow = 3/4" Diameter
brass pipe (both ends female)
6" - 10" Long - 3/4" Diameter
brass pipe (both ends threaded
male)
12