Gas piping – State GPG/GPV-540A User Manual
Page 11
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5. Attach a properly sized length of Selkirk Metalbestos model
PS or model G venting to the exhaust vent adapter using the
inner vee bands, see Figures 7 and 7B on page 10.
6. Fill the grooves in both inner vee bands with high-temp silicone
sealant, Dow Corning 736 or equivalent.
7. Position the inner vee bands around the inner pipe flanges
and tighten the screws securing the bands.
8. Align the outer channel band with the outer pipe grooves and
tighten the screws securing the bands.
9. Repeat steps 6-8 for each successive pipe length until the
venting reaches the heater.
10. Follow the manufacturer’s instructions for proper support and
guide spacing for horizontal runs of pipe, see Table 6.
TABLE 6.
Vent Diameter
S
F
8” - GPV -540A, 650A & 740A
15’ 3”
7’ 6”
S = Maximum spacing between two guides or a support
and a guide in either a vertical or horizontal direction.
F = Maximum height above a guide or support for free
standing system above a roof or parapet wall.
11. Use an expansion joint between any two fixed points in the
exhaust venting system wherever the expansion may exceed
1/4”. Selkirk Metalbestos model PS and model G venting
will expand by one inch per 100°F in gas temperature per
100 feet of vent length. The expansion can be calculated by
the following formula:
Expansion,
Vent length between 5
Inches
two fixed points, feet 100
If the expansion calculated is greater than 1/4”, an expansion
joint must be used between the two fixed points.
12. Attach the flue reducer included in the exhaust vent hood
package to the flue collar on the heater.
13. Attach the flue reducer to the vent system using a seal ring.
Attach this ring to the venting using the inner vee bands as
outlined in Steps 5-7.
14. Attach 8” air-intake connector to intake vent hood collar. It
may be necessary to use a slip-slip coupling to fit the pipe to
the intake vent hood.
15. Attach 8” air-intake connector back to the 6” burner air inlet
with 8” x 6” reducer. Prime and cement each joint to assure
gas-tight construction.
16. Seal all joints at the vent hoods with silicone sealant. Also
seal the joints at the flue collar and air inlet adapter. Joint
on the exhaust side must be sealed with high-temp silicone
sealant, Dow Corning 736 or equivalent.
wArNiNG
PriMErS AND CEMENTS ArE EXTrEMELy FLAMMABLE,
AND MUST NOT BE STOrED Or USED NEAr HEAT Or
OPEN FLAME. ALLOw ADEQUATE CUriNG TiME BEFOrE
OPErATiNG HEATEr.
DrAiN VALVE AND ACCESS PANELS
The heaters are equipped with a 3/4” NPT drain valves mounted
above and to the left of the burner.
An access panel is located above and to the right of the burner,
see Figure 8. This panel covers the cleanout opening in the tank
which is sealed by a gasket and cover. Another cleanout access
panel is located towards the back of the heater.
FiGUrE 8.
GAS PiPiNG
Contact your local gas service company to ensure that adequate
gas service is available and to review applicable installation codes
for your area.
Size the main gas line in accordance with Table 9 and 9A.
Minimum required gas supply pipe size is 1 1/4”. The figures shown
are for straight lengths of pipe at 0.5 in. w.c. pressure drop, which
is considered normal for low pressure systems. Note that fittings
such as elbows and tees will add to the pipe pressure drop.
TABLE 9
MAXiMUM CAPACiTy OF PiPE iN CUBiC FEET OF GAS PEr HOUr
(Based upon a Pressure Drop of 0.5 inch water Column
and 0.5 specific Gravity Gas and max. gas press. of .5 psig)
LENGTH
iN
Nominal iron Pipe Sizes, inches
FEET 1/2” 3/4” 1” 1 1/4” 1 1/2” 2” 2 1/2”
3”
4”
10
175 360 680 1400 2100 3960 6300 11000 23000
20
120 250 485 950 1460 2750 4360
7700 15800
30
97 200 375 770
1180 2200 3520
6250 12800
40
82 170 320 660
990 1900 3000
5300 10900
50
73 151 285 580
900 1680 2650
4750
9700
60
66 138 260 530
810 1520 2400
4300
8800
70
61 125 240 490
750 1400 2250
3900
8100
80
57 118 220 460
690 1300 2050
3700
7500
90
53 110 205 430
650 1220 1950
3450
7200
100
50 103 195 400
620
1150 1850
3250
6700
125
44
93 175 360
550 1020 1650
2950
6000
150
40
84 160 325
500
950 1500
2650
5500
175
37
77 145 300
460
850 1370
2450
5000
200
35
72 135 280
430
800 1280
2280
4600
=
x