RectorSeal 87031 Pro-Fit 3/8" to 1/2" Quick Connect Reducer, Push-to-Connect Refrigerant Fitting
The 87031 is the middle straight reducer in the Pro-Fit range, joining 3/8" to 1/2" inline. Both ends happen to seat to the same 1-1/4" depth, which makes it the easiest reducer in the family to mark and assemble — one setting on the gauge covers both tubes. It is a common transition on multi-zone work, where a branch running one diameter meets a trunk or an indoor unit running another, and the run continues straight through the change rather than turning at it. Brass, double O-ring sealed, 870 psig and 250°F continuous.
Is a 3/8" to 1/2" Reducer the Right Fitting Here?
The convenience of a shared insertion depth comes with one trap: 3/8" and 1/2" tubing are close enough in an attic or a crawlspace that the two ends of this fitting can be confused, and they are not interchangeable. Measure both tubes before cutting, and identify which port is which on the fitting before you push anything home — a push-to-connect joint does not give you a second attempt without the disconnect clip.
Beyond that it is a straightforward assembly. Cut square, deburr inside and out, mark 1-1/4" on each tube, push until the grip ring clamps, and pull firmly on both sides. Nothing is tightened; there is no nut on the fitting. Plan on roughly an inch and a half of clean straight tube on each approach and check the sealing area for scoring before committing.
Ideal for: Multi-zone branch-to-trunk transitions in a straight run, changeouts where the replacement equipment specifies a different suction size, lineset extensions joining mismatched tubing stock, and repairs in walls and ceilings where flame work is not permitted.
Transition at a corner instead? Use the RectorSeal 87034 reducing 90° elbow, which makes the same size change through a turn. The next step up is the 87032 1/2" to 5/8" reducer.
Fitting selection is based on measured tube outside diameter and system operating conditions, and line sizing must follow the equipment manufacturer's requirements. Installation must be performed by an EPA 608-certified technician in accordance with RectorSeal's published instructions and applicable mechanical codes. Request free sizing assistance, contact Budget Heating, or call 813-885-7999.
What's Included
| Fitting | 87031 — 3/8" to 1/2" Pro-Fit Quick Connect Reducer (one fitting) |
|---|---|
| Connection Type | Push-to-Connect, Straight Inline Reducer (3/8" x 1/2") |
| Body Material | Brass |
| Seal Design | Patented Double O-Ring and Grip Ring |
| Design Pressure | 870 psig (60 bar) |
| Continuous Operating Temperature | 250°F (121°C) |
| Insertion Depth | 1-1/4" on both ends |
| Assembly | Push-to-Connect — no tools, wrench, or torque required |
| Approved Tubing | Copper and Coated Aluminum Linesets |
| Certification | ICC-ES PMG-1616 (UL 207, UL 1963) |
One factory-assembled reducer per unit, cased 10 per box. Because both ends share the 1-1/4" depth, a single setting on the 87048 Pro-Fit Support Kit marking tool covers both tubes. The rest of the Pro-Fit range is on the RectorSeal brand page.
Reducer & Sealing Features
87031 Transition Body
- Straight brass body stepping 3/8" to 1/2"
- Matched 1-1/4" seat depth on both ends
- Patented double O-ring seal at each port
- Grip ring sized independently to each diameter
- Machined internal transition between the bores
- 870 psig design pressure on both sides
- 250°F continuous operating temperature rating
- Resists galling from vibration and pressure pulsation
- Sight window at each end
- Covered by ICC-ES PMG-1616 to UL 207 and UL 1963
Multi-Zone Straight Runs
- Single shared insertion depth simplifies marking
- No nuts, wrench, or torque on either end
- No brazing rod, flux, filler, or nitrogen purge
- Suits branch-to-trunk transitions in a straight run
- Handles changeouts specifying a different suction size
- Joins mismatched tubing stock on extensions
- Joins copper to copper or copper to coated aluminum
- Quick-release removal with the 87048 disconnect clip
- Approved for R-22, R-32, R-134a, R-290, R-410A, R-507, R-600a
- Cased 10 per manufacturer box
Specifications & Manuals
Product documentation includes the full Pro-Fit part number table, insertion depth specifications, approved tubing and refrigerant lists, and the ICC-ES PMG product rating certificate covering the certified pressure and temperature ratings.
Frequently Asked Questions
What does the 87031 connect?
3/8" O.D. tubing on one end and 1/2" O.D. on the other, in a straight inline transition. The two ends are not interchangeable — measure both tubes before cutting.
Do both ends of the 87031 seat the same depth?
Yes — 1-1/4" on both sides. It is the only Pro-Fit reducer where one gauge setting covers both tubes; the 87030 and 87032 each use two different depths.
How is the 87031 different from the 87034?
Both step 3/8" to 1/2". The 87031 does it in a straight line; the 87034 does it through a fixed 90° turn. Choose by whether the run continues straight through the transition.
Can I use a reducer to compensate for the wrong lineset size?
Line sizing is set by the equipment manufacturer for the run length, lift and capacity involved. A reducer executes a transition the design calls for — it is not a way to make undersized or oversized tubing acceptable. Check the installation manual.
What case quantity does the 87031 ship in?
10 per manufacturer case, matching the unions, elbows, elbow reducers and sockets. Only the service valves differ, at 5 per case.
Is the 87031 rated the same as a same-size union?
Yes. ICC-ES PMG-1616 applies 870 psig design pressure and 250°F continuous operating temperature across every Pro-Fit configuration, reducers included.
Click On Links Below For Documentation:
Technical Specifications
Brochure
Product Rating Certification
