The Dewey Switch is used primarily to detect a loss of vacuum in stacks and flues. Usually, when the vacuum fails, this indicates a loss of flame. The Dewey Air Switch detects this and can be used to turn off the fuel supply. This prevents explosions which come from un-ignited fuel.
The Dewey Air Switch saves lives.
The Dewey Air Switch was first designed in 1939 and patented in 1942. It is used primarily to detect a loss of vacuum in stacks and flues. Usually, when the vacuum fails, this indicates a loss of flame. The Dewey Air Switch detects this and can be used to turn off the fuel supply. This prevents explosions which come from un-ignited fuel.
Unique, is the extremely long mean time before failure, which is in excess of 20 years and 10Million operations. Relatively high current and switch ratings, make it possible to avoid isolation relays. Simple in design, the Dewey Air Switch functions equally as well in the positive pressure mode. Inverting the switch makes it function on positive pressures. This function has applications in flotation air driers, and polyethylene tube manufacturing.
Electrical Rating:
5 amps @115VAC or 115VDC
¾ HP at 230 VAC
MTBF: 10 Million Switch activations.
Models
114A Closes Switch on Rising Pressure: 0-0.33" W.C. Opens Switch on Falling Pressure: 0-0.20" W.C.
114AF Closes Switch on Rising Pressure: 0-0.22" W.C. Opens Switch on Falling Pressure: 0-0.10" W.C.
114B Closes Switch on Rising Pressure: 0-0.17" W.C. Opens Switch on Falling Pressure: 0-0.10" W.C.
