SECTION 8: U
NITARY
L
INEAR
& U-T
UBE
H
EATER
I
NSTALLATION
21 of 91
8.4 Unitary U-tube Heater Layouts
CTHN-Series heaters (except CTHN-40) are
approved for optional
u
-t
u
be config
u
rations.
The
u
-t
u
be may be installed in either a standard
horizontal position, 45° position or in an opposite 45°
position as sho
w
. When
u
sing a
u
-t
u
be config
u
ration, the follo
w
ing
additional r
u
les m
u
st be adhered to:
• A minim
u
m of 10' (3 m) on CTHN-60/80, a
minim
u
m of 15' (4.5 m) on CTHN-100/125, and a
minim
u
m of 20' (6 m) on CTHN-150/175/200 is
req
u
ired bet
w
een the b
u
rner and the
u
-t
u
be.
• For t
u
rb
u
lator installation,
• The b
u
rner m
u
st never be operated
in a tilted position.
The heater m
u
st be properly s
u
pported at all
locations.
.
FIGURE 18: U-tube Assembly Overview
U-tube
18" (457 mm)
Center to Center
U-clips
Reflector
End Caps
1
2
1
2
1
2
U-tube, Full 45°
1
2
Burner
Reflector
Turbulator
(With Select
Models)
Tube Clamp
Package
Burner
Tube
Tube
U-tube
Support Bracket
Reflector
Support
Couplings
U-tube, Standard
U-tube, Opposite 45°
Nut
Lock Washer
Lock Washer
Nut
U-bolt
Tight U-bolt
4" (10 cm) u-bolt,
secured to burner tube
with 1/4" (6 mm)
lockwashers and
1/4-20 hex nuts.
Loose U-bolt
4" (10 cm) u-bolt,
secured to bracket with
1/4" (6 mm) lockwashers
and 1/4-20 hex nuts on
top and bottom to
allow for tube expansion
and contraction.
