The first cold weeks expose vapor recovery units to conditions the summer log never recorded. Condensate behaves differently, seals stiffen and the first unloads of the season deserve closer attention than routine ones.
Condensate Systems Before Freezing Weather
Drain condensate pots and check heat tracing on lines that carry liquid hydrocarbons. A frozen drain valve masks a full pot until the unit backs up. Insulation that looks fine in autumn may hide wet spots that freeze through in January; squeeze-test it during the pre-season walk.
Heater and Temperature Settings
Where the unit carries heated components, verify setpoints against the winter commissioning sheet rather than the summer one. Startup current draws more from cold heaters, so check breaker sizing if settings changed over the year.
First Unload Observations
Watch the first truck unload of the season from start to finish. Vacuum cycling that ran smoothly in October may hunt in December as vapor density changes. Record vacuum setpoints, cycle counts and recovery tank rise, then compare against the same data from spring.
Membrane Modules in Cold Weather
Membrane performance shifts with feed temperature. Pressure readings that were normal in summer can sit at the edge of the recommended band in winter. Adjust valve positions gradually and log the new baselines so the crew recognizes seasonal drift rather than mistaking it for membrane aging.
Building the Winter Log
Winter operation rewards record keepers. A short daily line of temperatures, pressures and cycle counts lets the service technician separate weather effects from wear when spring maintenance comes around.