Midget Air Ductors
Selas Midget Air-Ductors (Product No. 4221) are designed to supply combustion air up to 16 osi when supplied with a small quantity of high pressure air.
Compressed air (above 30 psig) passing through the calibrated metering orifice entrains atmospheric air and delivers the total at some pressure to a gas-air mixer.
The selection table shows the approximate volumes of low pressure air (1 psig) which the various Midget Air-Ductors will deliver. When operating at capacities shown and 1 psig delivery pressure, about 25-35% of total air delivered will be high pressure air (measured on a free basis). At lower delivery pressures, the percentage of high pressure air will be less than indicated above.
Outlet pressures higher than 16 osi may be obtained with greater high pressure air flows. Increase compressed air flow 50% for 2 psig outlet pressure and 70% for 3 psig.
Typical Installation
Installation Suggestions
- Midget Air-Ductors should be connected directly to the mixer. Do not place any restrictions or valves between the air-ductor and mixer.
- Air-ductor outlet piping should be as short as possible. A straight connection (no elbows) is desirable.
- Compressed air line may be pipe or hose. All high pressure joints should be tight to prevent leaks.
- Open air shutter wide for maximum air entrainment.
- Open needle valve for capacity desired. Total air flow may be easily controlled by the needle valve.
Dimensions – “AD” and “ADC” Series
Dimensions – “AD” and “ADC” Series
Dimensions — “AD-F” and “ADC-F” Series
Ordering Information
- Select number, size and catalog number of Midget Air-Ductors required.
- “AD” series include the mixer, air orice and outlet coupling only. Add letter “C” to catalog number for complete assembly including needle valve and pressure gauge.
- Specify maximum air pressure and/or gauge range.
- Specify air capacity or orice drill size.
- Include complete shipping instructions.
