Raypak AVIA 264A, Installation And Operation Manual

Page: 19 / 158

19
MANUAL
SHUTOFF
VALVE
UNION
F10817
Figure 14. Manual Shutoff Valve Installation
Gas Pressure Adjustment Locations
CAP
ADJUSTMENT SCREW INSIDE
CLOCKWISE TO INCREASE
GAS VALVE
SUPPLY PRESSURE
TAP ON INLET SIDE
GAS FLOW
MANIFOLD
PRESSURE TAP
Figure 15. Gas Valve Adjustment
Pipe Sizing for Gas Connection
The capacities shown below are based on using SCH
40 black iron pipe. For capacities using other materials,
consult local codes.
Maximum Equivalent Pipe Length
ft (m)
Natural Gas 1000 BTU/FT³ 0.60 Specific Gravity @ 0.5 in.
WC Pressure Drop
Propane Gas 2500 BTU/FT³ 1.53 Specific Gravity @ 0.5 in
WC Pressure Drop
Model
No.
Size 3/4" Size 1" Size 1-1/4" Size 1-1/2"
NAT PRO NAT PRO NAT PRO NAT PRO
264
15
(4.6)
35
(10.7)
50
(12.2)
125
(38.1)
210
(64.0)
480
(146.3)
445
(135.6)
404 *
15
(4.6)
20
(8.8)
55
(16.8)
95
(29.0)
225
(68.6)
215
(65.5)
280
(85.3)
* A 3/4" gas line can be used for up to 5' (1.5 m) maximum length from
the gas valve in addition to the sediment trap.
Table L. Gas Pipe Sizing
Flow Rates
Model
Pipe Size
in. (mm)
Min. GPM (lpm) Max. GPM (lpm)
264/404 2 (50.8) 40 (151) 100 (379)
* When flow rates exceed maximum GPM an external auxiliary bypass
valve is required. See External Bypass Valve Section on page
21
for details.
Table M. Min/Max Flow Rates
F10818
Figure 16. Water Flow
Flow
GPM (lpm)
Pressure Drop
Ft. of Head (m of Head)
264 404 (w/Coils)
40 (151) 7.2 (2.2) 13.4 (4.1)
50 (189) 10.0 (3.1) 16.5 (5.0)
60 (227) 12.6 (3.8) 19.5 (5.9)
70 (265) 17.0 (5.2) 23.7 (7.2)
80 (303) 24.0 (7.3) 28.3 (8.6)
90 (341) 30.3 (9.2) 33.2 (10.1)
100 (379) 36.0 (10.9) 37.0 (11.3)
Table N. Heat Exchanger Pressure Drops
NOTE: Table capacity is based on 2" Schedule 40 piping.