Mueller Streamline 7/8" x 50' Soft Copper Refrigeration Coil, American Made, RTB7850
When the equipment's piping chart calls for a 7/8" suction line, the Mueller Streamline RTB7850 gives you 50 continuous feet of American-made, dead-soft copper refrigeration tube. Mid-size and larger residential split systems often specify 7/8" vapor lines, and the size also appears on commercial refrigeration and longer line runs where a 3/4" line would cause too much pressure drop. Mueller supplies the tube bright and dehydrated, then shrink-wraps and cartons every coil, giving installers clean domestic copper that can still be bent by hand on the job.
Is a 7/8" Copper Coil the Right Size?
Moving to 7/8" usually means the system has more capacity or a longer path between indoor and outdoor units. The larger bore lets more refrigerant vapor return to the compressor with less pressure loss, which helps the system reach its rated capacity. Many manufacturers list 7/8" as the standard suction size for their mid-to-larger residential tonnages, and some list it as an alternate size for long-line installs.
Bigger isn't always better. An oversized suction line can slow refrigerant velocity enough to hurt oil return, especially on vertical risers. Check the manufacturer's tables for your tonnage, equivalent length and lift before choosing 7/8".
Ideal for: Suction lines on mid-to-larger residential split systems, long-line installations, light commercial AC and medium-temperature refrigeration piping.
Need a larger diameter? Step up to the Mueller Streamline 1-1/8" x 50' Copper Line, RTB11850 for larger systems and extended suction runs.
Recommended line-size applications are general guidelines only. Correct suction line sizing depends on the equipment manufacturer's piping tables, system capacity, equivalent 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 | RTB7850 |
| Product Type | Soft Copper Refrigeration Tube Coil |
| Outside Diameter | 7/8" OD |
| Coil Length | 50 Feet |
| Temper | Dead Soft |
| Tube Condition | Bright, Thoroughly Dried / Dehydrated |
| Country of Origin | Made in the USA |
You get one 50-foot coil of 7/8" Mueller Streamline soft copper in its own protective carton. At this diameter, a continuous coil saves noticeable labor compared with joining short pieces, because every coupling you skip is one less braze and one less possible leak. Finish the run with 7/8" x 3/4" Rubatex insulation tubing on the suction line.
Condensing Unit & Evaporator Features
Mueller Streamline RTB7850 Copper Quality
- American-made Mueller Streamline refrigeration copper
- Uniform dead-soft temper from end to end
- Bright interior for clean refrigerant circuits
- Thoroughly dried and dehydrated
- Shrink-wrapped coil in an individual carton
- 50' continuous length cuts down on brazed couplings
- 7/8" OD for higher-capacity suction lines
- Backed by published Mueller submittal and standards documents
Why Contractors Stock the 7/8" Coil
- Suction line size for many mid-to-larger residential tonnages
- An option for long-line installs where pressure drop matters
- Light commercial rooftop and split-system piping
- Medium-temperature refrigeration suction piping
- Join sections with the RectorSeal Pro-Fit 7/8" quick connect union coupling
- Braze with supplies from our brazing gases and line flush category
- Pairs with the 3/8" RTB3850 coil on the liquid side
- Shop more copper lines and fittings
Specifications & Manuals
Mueller Streamline documentation covers submittal data, lead-free compliance and the copper tube standards behind the RTB7850, which helps with commercial approvals and specification checks.
Frequently Asked Questions
When should I use a 7/8" suction line instead of 3/4"?
Use 7/8" when the equipment manufacturer's piping tables call for it. That's typically on higher-capacity systems or longer line runs, where a 3/4" line would cause too much pressure drop and capacity loss.
Can a suction line be oversized?
Yes. A suction line that's too large lowers refrigerant velocity, which can hurt oil return to the compressor, especially on vertical risers. Size within the range the equipment manufacturer recommends.
Is 7/8" soft copper hard to bend by hand?
The RTB7850 is dead-soft, but larger diameters kink more easily than small tubing. Use gentle, wide-radius bends or a proper tube bender to avoid flattening the tube.
What insulation fits 7/8" copper tubing?
Use insulation sized for a 7/8" ID tube, such as 7/8" x 3/4" Rubatex insulation tubing. Choose a UV-resistant product, or protect the insulation, wherever the line runs outdoors.
Does Mueller provide documentation for job submittals?
Yes. This listing includes the Mueller Streamline copper submittal, a lead-free compliance document and copper standards information for project submittals and inspector questions.
What types of jobs call for 7/8" copper coils?
Residential replacement installs with larger split systems, light commercial AC work, long-line installations and medium-temperature refrigeration systems commonly use 7/8" copper.
Mueller Streamline Copper SubmittalMueller Streamline Lead-Free ComplianceMueller Streamline Copper Standards
