Honeywell SV2 Series User Manual page 19

GAS VALVE SIZING
The procedure below along with the valve capacity curves shown in
application. Valve selection may also be accomplished via the SV2 Series valve configuration tool, found at
http://www.combustion.honeywell.com/SV2Series.
Honeywell gas valve capacities are shown in
• Cubic feet per hour (CF/H) or cubic meters per hour (M3/H)
• For gas with a specific gravity/relative density of 0.64 (1 CF/H = 0.0283 M3/H).
• Capacities for natural gas are at ANSI Z21.21 or EN437 standard conditions of 15.6°C / 60°F and 1013.3 mbar / 406.9 in w.c.
/ 29.2 in. HG / 14.7 psi pressure
Sizing procedure:
1. Check the burner nameplate for:
a. The type of gas used.
b. The gas flow capacity. The capacity will be listed in BTU/H, KW/H or CF/H (cubic feet per hour).
2. Call the gas utility for information on:
c. The specific gravity (sp gr)/relative density.
d. BTU per cubic foot (BTU/ft
3. Find the burner capacity in:
e. CF/H. If the capacity is listed in BTU/H, convert to CF/H by the following formula:
• Capacity in CF/H = BTU/H (from burner nameplate) / BTU/FT
f. M /H. If the capacity is listed in in KW/H, convert to M
3
• Capacity in M
3
4. For gases with specific gravities/relative densities other than 0.64, correct the burner CF/H or M3/H from step 3. by
multiplying it by the proper conversion factor found in
Table 3. Gas Conversion Factors.
Type of Gas
G20 (100% CH4)
1
G25 (86% CH4, 14% N2)
Natural gas
LP gas (Propane)
G31 (100% C3H8)
1
1. Per EN437.
5.
Use the corrected burner capacity in CF/H or M3/H as calculated in step 4 (if applicable) when determining the gas valve
size in Figs. 7-12.
6.
Determine the available pressure drop across the valve and draw a horizontal line at this pressure in
7. Draw a vertical line in Figs. 7-12
gas with a specific gravity other than 0.64 as calculated in step 4 above.
8. Use the flange size with the appropriate valve size shown at the intersection of the horizontal and vertical lines in
If the intersection of the horizontal and vertical lines is close to the right-hand edge of the chart or not on the chart, you may
need to use the next higher valve size. Perform the same procedure for the next higher valve size to ensure the capacity can
be obtained with that valve at the required pressure drop.
SV2 Series Safety Shut-off Valves
V2F, V2V
Figs. 7-12
) or KW per cubic meter (KW/M
3
/H = KWH (from burner nameplate) / KW/M
Specific Gravity/ Multiply
Relative Density CF/H or
(average) M
3
0.555 1.00
0.612 1.05
1
0.640 1.07
1.530 1.66
1.550 1.67
at the capacity (CF/H or M3/H) previously determined, using the corrected capacity for a
Figs. 7-12 will help to identify the correct valve size for your
in:
) for the type of gas used.
3
(from gas utility)
3
/H by the following formula:
3
(from gas utility)
3
Table 3.
/H by:
19
SV2 SERIES SAFETY SHUT-OFF VALVES USER MANUAL
Figs. 7-12.
Figs. 7-12.