R-Pro › Field cases › Components
TXV Orifice Moisture Freeze-Up — Intermittent Suction Pressure Drop
Likely causes
Saturated dryer leaves moisture in circuit — intermittent orifice freezing
Check: Check pressure pattern — normal then sharp drop after 20–40 min then recovery after shutdown: confirms freeze-up; check for frost on piping just before TXV
What to do: Replace drier immediately → recover all refrigerant → vacuum below 1,000 microns 30+ min → recharge with certified refrigerant
No nitrogen purge during installation — atmospheric moisture remains
Check: Check installation records — no nitrogen flow purge record makes moisture the primary cause; confirm moisture indicator shows yellow
What to do: Replace drier + redo vacuum; if recurrence, consider installing two driers in series
Intermittent suction pressure drops are moisture freeze-up first — replace drier + redo vacuum for fastest fix
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
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