19124 – LEFT HAND THREAD ADAPTOR (A2L)

A2L refrigerants like R-32 and R-454B use left-hand (reverse) thread service ports to prevent accidental cross-contamination with older refrigerants. This Yellow Jacket adapter converts between 1/4″ left-hand female flare and 1/4″ right-hand male flare so you can connect standard gauge sets to A2L systems.

Specs: 1/4″ LH FFL x 1/4″ RH MFL, brass, for A2L refrigerant service

Replaces: 19124, AD44LH

Fits: A2L refrigerant systems (R-32, R-454B, etc.) with left-hand thread service ports. Universal adapter for all HVAC brands.

In stock at Open To Public HVAC Parts in Dallas. We test parts at the counter before you buy. Call or text (214) 340-9421.

Specs

• TypeLeft-hand thread adaptor
• UseConnects to A2L refrigerant cylinders (R-454B, R-32)
• WhyA2L cylinder valves are reverse threaded as a safety keying feature

Cross-reference numbers

This part replaces the following OEM and aftermarket numbers:

• 19124
• JB
• JBEQUIVALENT
• ROBINAIR
• ROBINAIREQUIVALENT
• YELLOWJACKET
• YELLOWJACKETEQUIVALENT

Not sure if your number matches? Call (214) 340-9421 or bring the old part in — bench-testing is free.

What size are HVAC service fittings?

1/4 inch flare is the standard service port on residential equipment. Most of the adaptors and caps here step between 1/4 inch and other sizes so you can connect gauges, a recovery machine or a vacuum pump.

Why do I need a left-hand thread adaptor?

A2L refrigerants - R-454B and R-32 - use LEFT-HAND (reverse) threaded cylinder connections. It is a deliberate keying change so A2L equipment cannot be cross-connected to older refrigerant. Without the adaptor a standard hose simply will not start on the tank.

Does the cap actually matter?

Yes. The cap is the primary seal on a service port, not the Schrader core. The core is a valve; the cap with its gasket is what holds refrigerant in over years. A missing cap is a slow leak you will not find with a sniffer for a long time.

What is a core removal tool for?

Taking the Schrader core out so you can pull a proper vacuum through a full-bore path instead of through a tiny valve. On anything bigger than a small system it is the difference between a real vacuum and a long afternoon.

Male or female - how do I tell?

Male threads are on the outside of the fitting, female on the inside. The listings here spell out each end, for example 1/4" male to 1/2" female, so you can match what you already have.

Do you stock these?

On the shelf at 10226 Plano Rd, Suite 104 in Dallas.