Flare Nuts and Unions

Category Overview

Flare nuts and unions are critical connection fittings used to join the copper tube lines between the indoor and outdoor units of split air conditioning systems, and they directly affect leak-tightness. A flare nut of the correct size and quality prevents refrigerant leaks, extends compressor life and minimises service calls after installation. At Yedepa.com we have brought together, under one roof, the flare nut and union types in the sizes most needed in the field by air conditioner installers, refrigeration technicians and technical service companies. In this category you can find connection fittings in different diameters and forms that can be used both in standard residential split air conditioners and in commercial refrigeration systems.

Products You Can Find in This Category

Our category includes the flare-type nuts, unions and flanged forged brass fittings most frequently chosen in air conditioner installation. You can quickly source the right size according to the diameter of the copper tube:

• 1/4 Air Conditioner Pipe Flare Nut — the standard size for the liquid line in residential split air conditioners.
• 3/8 Air Conditioner Pipe Flare Nut (Flanged, Forged Brass) — the high-strength professional choice that guarantees leak-tightness.
• 3/8 Air Conditioner Pipe Union — ideal for joining two copper tubes end to end.
• 5/8 Air Conditioner Pipe Flare Nut — used on the gas line connections of medium to high capacity air conditioners.
• 3/4 Air Conditioner Pipe Flare Nut — the large diameter preferred in commercial air conditioners and VRF systems.

Selection Criteria and Tips

The first thing to check when choosing a flare nut or union is the outside diameter of the copper tube; choosing the wrong size causes cracks and refrigerant leaks when the flare is made. Products with a forged brass body are stronger than their cast equivalents, so they should be preferred especially in high-pressure R410A and R32 systems. Applying a thin film of POE oil to the flare surface during installation improves leak-tightness. Always observe the tightening torque: approximately 18 N·m for 1/4, 42 N·m for 3/8 and 65 N·m for 5/8 can be taken as reference values. Over-tightening causes the nut to crack, while under-tightening leads to refrigerant leaks. After the job, always carry out a leak test with soap solution or an electronic leak detector.

Flare Nuts and Unions at Yedepa.com

At Yedepa.com, with our 10+ years of supply experience in the air conditioner spare parts category, we offer products in stock and ready to ship so that technicians can complete their jobs without losing time in the field. All flare nuts and unions in our category are manufactured from quality-controlled materials for long-lasting operation. We offer B2B price advantages and bulk order options for professional air conditioning service companies, installation teams and technical dealers. If you cannot find the size you are looking for or need a special fitting, you can contact Yedepa.com customer service for support from our expert team.