Mueller Streamline 3/8" OD Refrigerant Push x SAE Flare Adapter, American Made, ACP15726
A cracked or weeping flare is one of the most common mini split service calls, and the Mueller Streamline ACP15726 lets you fix it without re-flaring in a cramped spot. This American-made adapter pushes onto 3/8" OD copper on one end and tightens to a 3/8" flare connection on the other, using a flare nut made to SAE standards and JIS B 8607. It carries a 10-year limited warranty, is UL 207 Listed, and is rated for 700 PSI and a 200-micron vacuum on R-410A, R-32, R-454B, and other approved refrigerants — a dependable go-to for ductless service techs, installers, and HVAC contractors.
Is a 3/8" Push Fitting Flare Adapter the Right Size?
The ACP15726 fits 3/8" OD copper on the push end and a 3/8" flare on the other. On ductless equipment, 3/8" commonly serves as the suction (vapor) line on smaller-capacity heads and as the liquid line on some larger systems, so check the unit's service valve and connection sizes before ordering.
To replace a bad flare, cut the tube back past the old flare to clean, round copper, then deburr, clean, inspect, and mark a 1" insertion depth for the push end. On the flare side, apply a small amount of refrigerant oil to the flare face and tighten to Mueller's 3/8" range of 25–30 ft-lbs (34–42 N-m). Do not overtighten.
Ideal for: repairing leaking 3/8" flare connections, mini split vapor line hookups on smaller heads, line set extensions that end at a flare port, and service work where there is no room to swing a flaring tool.
Need a larger line size? Step up to the Mueller Streamline 1/2" Push Fitting Flare Adapter, ACP15727 for 1/2" flare connections.
Line size suggestions are general guidelines only. Always confirm actual tube OD and flare port size, follow the equipment manufacturer's instructions, and install per Mueller Streamline instructions and local codes. Request free sizing assistance, contact Budget Heating, or call 813-885-7999.
What's Included
| Fitting | ACP15726 — 3/8" OD Push x SAE Flare Adapter |
|---|---|
| Connection Type | Push (PU) x Flare; Push End Non-Removable |
| Flare Nut Standard | SAE (US) and JIS B 8607 |
| Flare Tightening Torque | 25–30 ft-lbs (34–42 N-m) — Do Not Overtighten |
| Push End Insertion Depth | 1" |
| Compatible Tubing | Hard-Drawn Copper per ASTM B280 & B88 (ACR, K, L); Soft Annealed Copper per ASTM B280 & B1003 |
| Vacuum Capability | 200 Microns |
| Origin & Warranty | Made in the USA — 10-Year Limited Warranty |
The ACP15726 push end ships with its grip ring and dual HNBR O-rings factory installed, so a repair comes down to a clean tube cut and a properly torqued flare. Pair it with the 3/8" push coupling, ACP10143 or 3/8" push 90 elbow, ACP02716, and evacuate with our charging, evacuation and recovery tools.
Adapter Construction & Application Features
ACP15726 Flare Connection Details
- Flare nut made to SAE standards in the US and JIS B 8607
- Suitable for mini split and VRV/VRF flare connections
- Flare torque: 25–30 ft-lbs (34–42 N-m)
- Do not overtighten — use a torque wrench
- Small amount of refrigerant oil on the flare face
- Forged brass construction
- UL 207 Listed refrigerant fitting
- IMC, IRC, and UMC certified (ICC-ES PMG-1625)
- Assembled and made in the USA
- Backed by a 10-year limited warranty
3/8" Field Repair Advantages
- Replaces a cracked or leaking field flare
- No flaring tool, torch, or crimp tool needed
- Push end seats by hand with a slight twist
- 1" insertion depth on the push end
- Stainless steel BackBite™ grip ring
- Dual factory-installed HNBR O-rings
- 700 PSI continuous operating pressure
- Holds a 200-micron vacuum
- Approved for R-410A, R-32, R-454B, R-407C, and more
- Six install steps printed on every bag
Specifications & Manuals
Use the submittal for the 3/8" flare torque, flare nut standards, push-end insertion depth, and leak-test procedure. The data sheet and brochure list ratings, approved refrigerants and oils, and the full flare adapter range.
Frequently Asked Questions
How does the 3/8" ACP15726 compare with the 1/4" ACP15725 flare adapter?
Both use a 1" push-end insertion depth and share the same pressure rating and approvals. The ACP15726 fits 3/8" tube and flare ports, and its flare torque is higher at 25–30 ft-lbs, versus 10–13 ft-lbs for the 1/4" size.
Should I oil the flare face when installing the ACP15726?
Yes. Mueller recommends applying a small amount of refrigerant oil to the flare face for best results before tightening to the specified torque.
Can the ACP15726 replace a leaking field flare on a mini split?
Yes. Recover the charge as required, cut the tube back past the bad flare to clean copper, prepare the end, and push on the ACP15726. Then torque the flare end to the service valve or unit connection and pressure test.
Is the ACP15726 approved for R-32 mini splits?
Yes. R-32 is on Mueller's approved refrigerant list, along with R-410A, R-454B, and many other HFC, HFO, and A2L refrigerants. R-22 is not approved.
What happens if the ACP15726 flare nut is overtightened?
Mueller warns not to overtighten flare connections, since excess torque can damage the flare and cause a leak. Use a torque wrench and stay within 25–30 ft-lbs (34–42 N-m).
Can the ACP15726 be disconnected later?
The flare end is a threaded connection that can be loosened from the equipment, but the push end is permanent and non-removable. To reposition the tubing, cut the tube and install a new fitting.
Mueller Streamline Push Fittings BrochureMueller Streamline Push Fittings Data SheetMueller Streamline Push Fittings Submittal
