Hammer union pressure transmitter
Model 425 Honeywell Sensing and Control

Honeywell’s Model 425 Wing Union pressure sensors (also known as Hammer Union pressure sensors) are rugged pressure transmitters designed for use with Weco® 1502 fittings.
Now available in two accuracy levels, Model 425 (±0.2 % BFSL [Best Fit Straight Line] – Standard) or Model 425 – High Accuracy (±0.1 % BFSL – High Accuracy), is designed for use in demanding land-based and off-shore oil and gas exploration and drilling applications, such as mud pumping, fracturing and cementing, well head measurement, standpipe, and well stimulation.
Built on Honeywell’s time-proven Wing Union all-welded, one-piece, hermetically sealed stainless steel design, the Model 425 provides highly accurate and reliable data for detection of changes in pressure, allowing the operator to quickly adjust media flow pressure during drilling operations. This helps drilling operators optimize oil withdrawal rates and profile potentially dangerous conditions such as gas bubbles to increase drilling personnel safety.