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Our highest precision conventional large diaphragm pressure switch provides maximum dependability. In addition, it incorporates a visible set point indicator for maximum convenience. UL and CSA listed, FM approved for general service, these switches are suitable for most applications in air conditioning and industrial service. Electrical capability of 15 amps handles most small electrical loads.

CAUTION: FOR USE ONLY WITH AIR OR COMPATIBLE GASES.

SPECIFICATIONS
Service: Air and non-combustible, compatible gases.
Wetted Materials: Consult factory.
Temperature Limits: -30 to 110°F (-34.4 to 43.3°C).
Pressure Limits: 10 psig (68.95 kPa) continuous, 25 psig (172.4 kPa) surge.
Switch Type: Single-pole double throw (SPDT).
Repeatability: ±1%.
Electrical Rating: 15 A @ 120-480 VAC, 60 Hz. Resistive, 1/8 HP @ 125 VAC, 1/4 HP @ 250 VAC, 60 Hz.
Electrical Connections: 3 screw type, common, normally open and normally closed.
Process Connections: 1/8" female NPT.
Mounting Orientation: Diaphragm in vertical position. Consult factory for other position orientations.
Set Point Adjustment: Screw type with enclosed scale.
Weight: 4 lb 14 oz (2.21 kg).
Agency Approvals: UL, CSA, FM.

OPTIONS -- Consult Factory for Pricing

-MIL Environmental Construction. Unlisted Model 1635 can be furnished with a special snap switch sealed against the environment for high humidity, exposure to fungus, and/or for military applications. Similar to Model 1638 except dead band is slightly greater and some lower set points may not be available. Specify Model 1638-(range no.)-MIL and required set point in ordering.

-WP Weatherproof Housing. 16 ga. steel enclosure for unusually wet or oily conditions. Withstands 200 hour salt spray test. Gasketed cover. Weight: 20 lbs. Switch must be installed at factory. Specify Model 1639-(range no.)-WP when ordering.

-EXPL Cast aluminum housing with dome cover. Weight 47 lbs. (21 kg). Switch must be installed at factory. Specify Model 1639-(range no.)-EXPL when ordering. Rated Class I, Div. 1 & 2, Groups C, D; Class II, Div. 1 & 2, Groups E, F, G; Class III and NEMA 7 CD, 9 EFG.