9
Dispersion Tube Installation with Condensate Drain
Vapor Hose
When a vapor hose and stainless steel dispersion tube
are used, they should be pitched back to the humidifier.
A minimum slope of 2" per foot (165 mm/m) (with no “low
spots”) is recommended. Vapor hose should be sup-
ported to prevent sags or low spots. When this is not
possible due to duct elevation or an obstruction, alternate
arrangements should be used as shown in figure 15-1
or 15-2.
Any condensate that forms in the vapor hose must be
removed. Preferably, it should be returned to an open
drain with a water seal of sufficient height to contain the
duct static pressure, as shown in figure 10-1.
The condensate can also be returned to the
VAPORSTREAM
®
VLC, as shown in figure 10-2, with an
air vent. This method requires a water seal and an air gap
to prevent back pressure from the VLC chamber. Exces-
sive back pressures imposed on the humidifier may lead
to dispersion tube(s) spitting, lost water seals, or leaking
gaskets. When the distance between the humidifier and
the dispersion tube(s) exceeds 10 feet (3 m), consult
factory for special recommendations.
Hard Piping (when used)
• Hard piping should have a minimum I.D. of 1½" (35 mm).
• A minimum pitch of 2" per foot (165 mm/m) back to the
humidifier must be maintained.
• 90° elbows are not recommended; use two 45° elbows
one foot apart instead.
• Thin-walled tubing will heat up faster and cause less
start up loss than heavy-walled pipe.
• Insulating the rigid piping will reduce output loss due to
condensation.
Tube Mounting
•
Mount dispersion tubes pitched as stated above.
•
Tubelets must discharge perpendicular to air flow.
•
Return line piping material must be suitable for 212°F
(100°C) water.
Min. Condensate Drain Line Sizing
• One or two tubes: 3/4" (20 mm) I.D.
• Three or more tubes: 1" (25 mm) I.D.
Figure 9-1: Single Tube
½" O.D. Stainless Steel
(condensate drain)
Movable Duct Plate (Can be mounted within limits of 2.5" (65 mm).)
¼" NPT Coupling
.625 Dia.
"B" Dia. (TYP)
A
A
A
2.5"
(65
mm)
2"/ft (165 mm/m) Pitch
Mounting Nut
Pre-molded High
Temperature Resin Steam Tubelets
Insertion Length
OM-351
Table 9-1: Dispersion Tube Capacities
A
3.25"
(85 mm)
1/8"/ft (10 mm/m) Pitch
DISPERSION TUBE INSTALLATION
Mounting Nut
y
t
i
c
a
p
a
C
e
b
u
T
.
a
i
D
t
u
o
h
t
i
W
n
i
a
r
D
h
t
i
W
n
i
a
r
D
A
B
"
½
1
)
m
m
8
3
(
r
h
/
s
b
l
8
2
)
h
/
g
K
3
1
(
r
h
/
s
b
l
7
5
)
h
/
g
K
6
2
(
"
5
2
.
3
)
m
m
5
8
(
"
1
5
.
1
)
m
m
0
4
(
"
2
)
m
m
0
5
(
r
h
/
s
b
l
7
5
)
h
/
g
K
6
2
(
r
h
/
s
b
l
5
8
)
h
/
g
K
9
3
(
"
0
0
.
5
)
m
m
0
3
1
(
"
3
0
.
2
)
m
m
0
5
(
3.25"
(85 mm)