SECTION 6: C
RITICAL
C
ONSIDERATIONS
15
NOTE:
1. All dimensions are from the surfaces of all tubes, couplings and elbows.
2. Clearances B, C and D can be reduced by 50% after 25' (7.5 m) of tubing downstream
from where the burner and burner tube connect.
*When installed in the first 10' (3 m).
FIGURE 17: U-TUBE, OPPOSITE 45
°
REFLECTOR
(inches)
(centimeters)
Model
A
B
C
D
A
B
C
D
CTHN-40
- UNAPPROVED -
- UNAPPROVED -
CTHN-60
8
45
45
10
20
114
114
25
CTHN-80
9
55
54
10
23
140
137
25
CTHN-100
10
56
57
10
25
142
145
25
CTHN-125
10
58
63
10
25
147
160
25
CTHN-150
10
61
66
20
25
155
168
51
CTHN-175
10
68
69
20
25
173
175
51
CTHN-200
10
71
73
20
25
180
185
51
A
C
D
B
FIGURE 18: 2-FOOT DECO GRILLE, 1-FOOT DECO GRILLE AND PROTECTIVE GRILLE
(inches)
(centimeters)
Model
A
B
C
D
A
B
C
D
CTHN-40
5
20
41
20
13
51
104
51
CTHN-60
5
27
51
27
13
69
130
69
CTHN-80
5
30
58
30
13
76
147
76
CTHN-100
5
32
60
32
13
81
152
81
CTHN-125
5
35
65
35
13
89
165
89
CTHN-150
5
39
71
39
13
99
180
99
CTHN-175
8
44
74
44
20
112
188
112
CTHN-200
8
47
76
47
20
119
193
119
A
C
D
B
FIGURE 19: LOWER CLEARANCE SHIELD*
(inches)
(centimeters)
Model
A
B
C
D
A
B
C
D
CTHN-40
5
25
22
25
13
64
56
64
CTHN-60
5
30
27
30
13
76
69
76
CTHN-80
5
37
37
37
13
94
94
94
CTHN-100
5
39
39
39
13
99
99
99
CTHN-125
5
41
41
41
13
104
104
104
CTHN-150
5
43
50
43
13
109
127
109
CTHN-175
- UNAPPROVED -
- UNAPPROVED -
CTHN-200
- UNAPPROVED -
- UNAPPROVED -
A
C
D
B
