Mueller Streamline 3/8" x 50' Soft Copper Refrigeration Coil, American Made, RTB3850
The Mueller Streamline RTB3850 is a 50-foot coil of 3/8" OD dead-soft copper refrigeration tube, made in the USA by one of the best-known names in HVAC/R copper. It's the go-to small-diameter line for split-system liquid lines, compressor oil lines and general refrigeration service. Mueller dries and dehydrates the tube, leaves it bright inside, and ships each coil shrink-wrapped in its own carton, so it reaches the jobsite clean and ready to bend, flare or braze. Contractors, service techs and refrigeration installers who want domestic copper on the truck will find the 3/8" coil one of the most useful sizes to keep in stock.
Is a 3/8" Copper Coil the Right Size?
On most residential and light commercial split systems, 3/8" OD is the standard liquid line size. Liquid lines carry refrigerant in its dense liquid state, so a small diameter moves plenty of refrigerant while keeping the charge down. Beyond liquid lines, 3/8" copper is often used for oil lines, small refrigeration circuits and short repair sections where a technician needs to replace damaged tubing.
The right line size always comes from the equipment manufacturer's piping tables. Total line length, vertical lift, the number of bends, system capacity and refrigerant type all affect whether 3/8" is correct for the liquid side. Long runs or larger-tonnage equipment can call for a different diameter, so check the installation literature before cutting into the coil.
Ideal for: Split-system AC and heat pump liquid lines, walk-in cooler liquid lines, oil lines, line set repairs and general service-van stock.
Need a larger diameter? Step up to the Mueller Streamline 3/4" x 50' Copper Line, RTB3450 for suction lines on smaller split systems and refrigeration equipment.
Recommended line-size applications are general guidelines only. Correct liquid and suction line sizing depends on the equipment manufacturer's piping tables, system capacity, line length, vertical lift and refrigerant type. Request free sizing assistance, contact Budget Heating, or call 813-885-7999.
What's Included
| Brand | Mueller Streamline |
|---|---|
| Model | RTB3850 |
| Product Type | Soft Copper Refrigeration Tube Coil |
| Outside Diameter | 3/8" OD |
| Coil Length | 50 Feet |
| Temper | Dead Soft |
| Tube Condition | Bright, Thoroughly Dried / Dehydrated |
| Country of Origin | Made in the USA |
Each RTB3850 is one continuous 50-foot coil of 3/8" soft copper. That's enough to run a full liquid line on a typical residential install with tubing left over for a repair. Because the coil is one piece, you can uncoil and route it with fewer joints, which means fewer braze points that could leak. Mueller shrink-wraps each coil and packs it in its own carton to keep moisture and debris out until you're ready to use it.
Condensing Unit & Evaporator Features
Mueller Streamline RTB3850 Copper Quality
- Made in the USA by Mueller Streamline
- Consistent dead-soft temper for smooth hand or tool bending
- Bright interior finish
- Thoroughly dried and dehydrated at the mill
- Shrink-wrapped and boxed in an individual carton
- Continuous 50' coil reduces fittings and joints
- Small 3/8" OD keeps the liquid-line refrigerant volume down
- Part of Budget Heating's Made in America copper and fittings lineup
Where the 3/8" Coil Works Best
- Liquid lines on residential split AC and heat pump systems
- Liquid lines on walk-in cooler and freezer refrigeration systems
- Compressor oil lines and small-diameter service piping
- Replacing damaged or kinked liquid line sections
- Flares cleanly with the RectorSeal Pro-Fit precision flaring kit
- Pairs with the Mueller Streamline 3/8" push fitting 90 elbow for flame-free connections
- Works with the RectorSeal 87043 3/8" quick connect service valve
- A practical, high-use size for service-van stock
Specifications & Manuals
Product documentation includes the Mueller Streamline copper submittal, lead-free compliance information and copper tube standards to support product approval, specification and installation.
Frequently Asked Questions
What is 3/8" copper tubing typically used for in HVAC work?
On most residential and light commercial split systems, 3/8" OD copper is the standard liquid line size. It's also used for oil lines, small refrigeration circuits and liquid line repairs. Always confirm sizing against the equipment manufacturer's piping tables.
Is the Mueller RTB3850 made in America?
Yes. Mueller Streamline lists its ACR copper tube as made in the USA, and the RTB3850 is part of Budget Heating's Made in America copper collection.
Can I flare the RTB3850 without annealing it first?
The RTB3850 ships in a consistent dead-soft temper, so it's ready to flare, swage or bend out of the box with proper tools. Cut it with a tube cutter and deburr the end before making a flare.
How does Mueller keep the inside of the coil clean?
Mueller supplies its refrigeration service tube bright inside and thoroughly dried and dehydrated. Each coil is shrink-wrapped and packed in its own carton to help keep moisture and contamination out until installation.
Will one 50' coil cover a full liquid line run?
A 50-foot coil covers the liquid line on many residential installs and leaves extra tubing for service work. Measure the actual routing, including vertical rises and bends, before you start.
Who usually buys 3/8" soft copper coils?
HVAC contractors, refrigeration technicians, service companies and facility maintenance teams keep 3/8" coils stocked for new installs, equipment change-outs and leak repairs.
Mueller Streamline Copper SubmittalMueller Streamline Lead-Free ComplianceMueller Streamline Copper Standards
