- 2051CD Differential Pressure Transmitter 1 Pressure Upper Range Limit: 25 inH2O (62.2 mbar) A 4-20 mA with Digital Signal Based on HART Protocol 33 Process Flange Type: Coplanar Flange Material: Cast C-276 Drain Vent: Alloy C-276 Isolating Diaphragm: Alloy C-276 A O-Ring: Glass-Filled TFE 1 Sensor Fill Fluid: Silicone A Housing Material: Polyurethane-Covered Aluminum Conduit Entry Size: 1/2-14 NPT H7 Traditional Flange 316 SST Alloy C-276 Drain/Vent B2 Traditional Flange Bracket for Panel Mounting CS Bolts I1 ATEX Intrinsic Safety L4 Austenitic 316 SST Bolts M5 LCD Display