Mercoid, SA1111E-A4-K1, Series SA1100 Diaphragm Operated Pressure Switch, 10-150 psig, 1/4" FNPT, Aluminum ChamberSeries SA1100 Diaphragm Operated Pressure Switch, , 10 - 150 psig, Snap Action Switch, Pressure Chamber - Aluminum, Diaphragm - Buna-N, Seal Material - Buna-N, SPDT Switch & 1/4" Female NPTVisible Setpoint, Adjustable Deadband, Hermetically Sealed Snap Switch, Weatherproof and Explosion-proofWeatherproof and Explosion-Proof in One Economical Enclosure Extremely rugged construction assures excellent reliability in chemical, petroleum and industrial plants. New design also provides burst pressure protection to 3000 psi (206 bar). The rolling diaphragm design maintains a constant effective area to minimize friction. This results in a minimum deadband as low as 5% of full scale. Since many applications require higher deadbands, the SA1100 includes a separate adjustment of this when necessary. A pump being used to control liquid level in a tank would be a typical situation where this feature would be important. Both setpoint and deadband adjustments are protected, yet clearly visible behind a clear polycarbonate window and are fully isolated from the electrical components for additional safety. A 7/16" open-end wrench is the only tool required to change settings. Terminal blocks are provided for switch wiring connections and both internal and external ground screws are included. Standard housing is weatherproof to NEMA standards 1 through 4X and 13; explosion-proof to NEMA 7, Class I, Groups B, C & D; NEMA 9, Class II, Groups E, F & G. Chemical, petroleum, food and drug processing industries. Used indoor, outdoor or in explosion-proof area.ApprovalsATEX Approval ATEX QAN CE Approval (ATEX) CE Approval (not ATEX) CSA Approval IECEx Certificate UL-Switches-Hazardous Locations-US.