What it is and how it sits in the loop
The ABB 266HDHFRMB1L1 + S26REHN2SFSM1N1SNNN is a gauge pressure transmitter from the 266HDH line, paired with a Model S26RE rotating flange diaphragm seal for flush, direct-mount service, and it ships as a single calibrated assembly with the seal quoted separately. The 266HDH platform is rated at 0.06 % base accuracy, which is the reference figure against which span, zero, and total error are trimmed at the factory — adequate for custody-class and tight-loop control on vessels, lines, and filter housings.
Process side: direct-mount seal and wetted materials
The seal side is configured as a direct-mount flush diaphragm with the high-pressure side on the transmitter side of the connection, and the seal itself follows EN 1092-1 on a PN 16-40 / DN 50 flange — meaning the transmitter bolts straight onto the process tapping without a capillary, which removes the temperature-induced zero shift that a long capillary would introduce. Wetted parts are AISI 316 L ss with silicone oil PMX 200 10 cSt as the fill fluid, so the diaphragm and fill are compatible with most water, steam, chemical, and hygienic lines that the 316 L / silicone pairing is specified against.
Housing, conduit, and local readout
The electronics housing is the aluminium alloy barrel version with an M20 x 1.5 (CM 20) electrical entry, so conduit or cable gland selection on site is sized to the M20 thread and the housing itself provides the environmental and EMC enclosure. A digital LCD integral display is fitted, giving local pressure readout at the transmitter without needing a handheld terminal for verification during walk-around checks.