Why Copper Fittings Aren’t All the Same

Copper fittings are fundamental components in HVAC-R and refrigeration systems, but not all fittings are designed equally. PAC, ACR, and CO₂ copper fittings may look similar at first glance, yet they are engineered with different materials, pressure tolerances, and application focuses. Choosing the right fitting ensures safety, efficiency, and compliance with modern refrigeration requirements.

PAC Copper Fittings
PAC Copper Fittings

Durable copper fittings designed for HVAC applications, ideal for moderate-pressure heating and air-conditioning systems.

Materials: C1220 Copper
%CuP
MINIMUM99.9%0.015%
MAXIMUM–0.040%
Pressure Ratings
SIZE (IN)PSIBAR
1/4″72550.2
3/8″72550.2
1/2″62042.9
5/8″57539.8
3/4″50534.8
7/8″46532.1
1-1/8″39527.2
1-3/8″35024.2
1-5/8″32522.5
2-1/8″29020
2-5/8″26518.5
Size Range: Up to 3-1/8″
Brazing Process

Standard HVAC brazing practices commonly using phosphorus-copper or silver-bearing brazing alloys.

Applications

Air conditioning and heating water systems where pressures are moderate.

ACR Copper Fittings
ACR Copper Fittings

Cleaned, dehydrated copper fittings made for refrigeration systems, preventing contamination while handling higher pressures than PAC.

Materials: C1220 Copper
%CuP
MINIMUM99.9%0.015%
MAXIMUM–0.040%
Pressure Ratings
SIZE (IN)PSIBAR
1/4″100068.9
3/8″100068.9
1/2″100068.9
5/8″100068.9
3/4″100068.9
7/8″90062
1-1/8″70048.2
1-3/8″70048.2
1-5/8″70048.2
2-1/8″70048.2
2-5/8″70048.2
Size Range: Up to 4-1/8″
Brazing Process

Requires careful nitrogen purging during brazing to maintain cleanliness and avoid oxidation inside the line.

Applications

Commercial and residential refrigeration systems using HFC, HFO, or HC refrigerants.

CO₂ Copper Fittings
CO2 Copper Fittings

Heavy-duty alloy fittings engineered for transcritical and subcritical CO₂ refrigeration, built to withstand extremely high operating pressures.

Materials: C19400 Copper
%CuPbZnFeP
MINIMUM97%–0.05%2.1%0.015%
MAXIMUM–0.03%0.20%2.6%0.15%
Pressure Ratings
SIZE (IN)PSIBAR
1/4″1885130
3/8″1885130
1/2″1885130
5/8″1885130
3/4″1885130
7/8″1885130
1-1/8″1885130
1-3/8″1885130
1-5/8″1885130
2-1/8″1885130
2-5/8″––
Size Range: Up to 2-1/8″
Brazing Process

High-temperature brazing processes with nitrogen purging, often requiring silver alloys to ensure joint strength under extreme pressure.

Applications

Modern supermarket refrigeration, industrial cold storage, and any system where CO₂ is the refrigerant of choice.