The S365 Charging Jacket is a reliable way to charge TXV systems in cold weather. Normally, low temperatures remove too much heat from the condenser coils, so HVACR professionals should only work on TXV systems when the outside air temperature is 70 deg F or higher. Now, the new Fieldpiece Charging Jacket solves that problem, and TXV systems can be accurately charged down to 37 deg F outside temps. It's the perfect tool to dramatically extend the hours in a day, and the days in a year, where techs can install, service, and charge TXV systems. Made from parachute-grade material, the Charging Jacket is attached to the top of a split TXV system with hooks, so that the air inlet is not restricted. Then the unit is turned on the jacket puffs up from the air being forced out of the air outlet. The top is then adjusted with a drawstring until the proper pressure differential is reached between the high and low side (between 160 psi and 220 psi for R410A; and between 100 psi and 145 psi for R22). Once the systems stabilizes for 15 minutes at the correct pressure differential, the system is ready to be charged.