Machine Performance
Air consumption climbs faster than pressure does. The optimum is real, and it is never the pressure that kills the last stop.
— /h
Stops saved less the extra air bought
Stop reduction is modelled as linear in pressure, and it is not — the relationship saturates, so beyond the pressure that reliably lands the weft on the far side, further increases buy nothing but air, and this model will keep promising savings that do not exist. Fit the sensitivity over the narrow range you actually operate in and re-fit it when style or yarn changes. Excess pressure also has costs outside this calculation: weft breakage at the nozzle, selvedge waste from over-travel, and accelerated nozzle wear. The fleet figure assumes every loom runs the same style at the same pressure all year, which no shed does.
Air-Jet Insertion Pressure vs Weft Stop Economics — free, with the formula and a worked example, at Textile School.