Notes:
• Dashed lines indicate provided by installer.
• The water supply inlet is more than 1” (25 mm) above the skim/overflow port, eliminating the possibility of backflow or siphoning from the chamber.
No additional backflow prevention is required; however, governing codes prevail.
Shock arrester
recommended to
reduce water hammer
¼” (DN8) compression
fitting on fill valve
connection to water
supply line; water
pressure must be between
25 psi and 80 psi
(175 kPa and 550 kPa);
water conductivity
minimum 100 µS/cm2;
fill valve has an integral
strainer
Water supply line
Spill funnel;
plumb to
floor drain
1” (25 mm)
air gap
¾” (DN20) copper
chamber drain and
overflow piping,
rated for 140°F
(60°C). If piping run
is over 10’ (3 m)
increase pipe
to 1¼” (DN32).
Open drain required. Locate air gap only in
spaces with adequate temperature and air
movement to absorb flash steam; otherwise,
condensing on nearby surfaces may occur.
Refer to governing codes for drain pipe size
and maximum discharge water temperature.
Install plumb
Steam hose
(maximum run 10’ [3 m])
OM-4017
1” (25 mm) flexible drain
hose and clamps
FIGURE 21 – Field Piping Overview Showing Hose Drain Connection
The final connection size is 1” (DN25) hose or ¾” (DN20) copper for the chamber drain. Do not reduce this connection size. (See Figures 21 and 22 for proper drain piping configurations.) A 12” (305 mm) piece of 1” (DN25) hose is provided to function as the flexible connection from the drain valve to the field installed drain plumbing. The flexible connection provides a disconnect point so that the chamber can be removed for cleaning. (See Figure 21). Hard piping can be connected directly to the drain valve, but the vertical drop should be minimized prior to a horizontal run. Install a union at the beginning of the horizontal run to remove the chamber for cleaning. (See Figure 22). If the equivalent length of pipe from the humidifier drain to the plumbing system drain is more than 10’ (3 m), increase the pipe size to 1¼” (DN32). See Figures 21 and 22.24