By replacing the elastic creep deflection of conventional pressure switch sensors with the negative spring rate of a disc spring combination pressure switches have now become binary like computers. This revolutionary design has been proven to be so reliable that on jet aircraft, for instance, it has been the only design acceptable for many decades. The diaphragm is not a sensing element. It simply seals the media and transfers pressure to the disc spring, which responds instantaneously when system pressure reaches the set points.

Design Features

• Extremely fast response
• Set points stay set – not sensitive to shock, vibration, temperature variations, or other ambient conditions
• Vapor type temperature sensing is more accurate than bimetallic types – simpler than thermocouples
• No “tracing” because of fluctuations in system temperatures – no “teasing” of the electrical element. The switch is either “on” or “off.”
• Reduces the adverse effects of pump ripple, contact chatter, fatigue, premature wear, and other common switch problems
• Maximum life expectancy with lifelong reliability and precise repeatability assured
• A wide range of set points available in each switch model series.

646 Series Features

• Explosion Proof Div. 1, 2
• U.L./CSA
• NEMA: 4, 7, 9, 13
• Ambient Temp. Range: -30 to 160 deg F

This switch has an adjustment range of: 380° to 520°F