NOZZLE MIX SYSTEMS
air
16 osi
5 D
3 D
4 pipe dia.
gas
10 pipe dia.
16 osi
Limiting Orifice Valve high fire ratio adjustment
ADJUSTMENT OF HIGH FIRE AIR/FUEL RATIO
(Refer to page 29 and to "Sheet 7218-2 Instructions" regarding procedure for lighting and turning up to high fire rate) Set the limiting orifice valve for the desired air/fuel ratio on high fire. This gives the proper flow of gas at 16 osi to match the flow of air at 16 osi. If the air pressure is changed, the gas pressure will follow this change, and the air/ gas ratio will remain unchanged. This high fire ratio setting is an orifice size adjustment. Its setting at any pressure affects the air/gas ratio at all pressures. This high fire ratio adjustment should be made first, then low fire. Air capacities of burners are determined by their orifice sizes which are fixed. These capacities at various air pressures are listed in the burner bulletins.
20
Made with FlippingBook - Online catalogs