25LB R407A (R-407A) Refrigerant Gas | 30 Cylinders

Depth on a service book is bought against a forecast, not against a fault. Last season's consumption, the age of the plant under contract and the known bad actors on the list tell you what the cooling season will draw. A run of 30 cylinders covers the mid-season week when a regional heatwave has every contractor ringing the same suppliers. Rotate stock so nothing sits at the back for years, and log what went into which job at the van — easier written down than reconstructed later.

The blend is zeotropic — R-32, R-125 and R-134a put up as one service gas — so it behaves as a mixture everywhere in the system, at the gauges and at the cylinder. Low and medium temperature commercial refrigeration is the home ground: supermarket racks, display cases, walk-in coolers and freezers, cold stores, beverage and ice equipment. It came in for R-22 and R-502 in direct-expansion plant and sits alongside R-404A. New kit now goes out on lower-GWP blends, so this keeps an installed base running.

Charge as liquid. Draw vapour off the cylinder and what stays behind shifts off spec, so weigh liquid in through a metering device, or throttle it into the suction side with the compressor running. Take superheat and subcooling from bubble and dew point columns, never one saturation figure. Pressures sit a little above R-22 at the same conditions and below R-404A: close, not a drop-in. Polyolester oil; mineral oil will not come back. Non-flammable but heavier than air, so ventilate pits and plant rooms. Cylinders upright, charging on a scale, recovery not venting.