TD-31040 Heat Pipe & Heat Exchanger Tube End Closing Machine | Stainless & Copper Tube Sealing
What a heat exchanger tube end needs
After closing, heat pipes and heat exchanger tubes see internal pressure and repeated thermal cycling. The closure must have no weld porosity and no plug gap. TD-31040 cold roll-spins the tube end into a seamless one-piece dome; the wall thickens at the closure, which suits thermal cycling better than a welded cap.
Tube range
| Item | Spec |
|---|---|
| Tube OD | Ø10–40 mm |
| Wall thickness | 0.8–2.0 mm standard; heavy-wall stainless evaluated per size |
| Materials | Stainless steel (304, 316), copper, carbon steel, aluminum. Good ductility required; welded tube needs a sound seam |
| Closed-end type | Fully closed dome (radius adjustable on the machine, no mold change), or dome with a center hole of independently adjustable diameter |
Production examples
| Material | End type |
|---|---|
| Stainless steel Ø12.7 × 1.7 mm | Fully closed dome |
| Stainless steel and copper | Dome end or center hole |
| Copper heat pipe | Small-diameter flat closing on TD-21025 flat-type machine |
For heavy-wall or special tubes, send a sample for evaluation.
Dome end or flat end
TD-31040 makes a dome-shaped closed end, the strongest form for pressure and the right choice for stainless and heavy-wall tube. For a flat closed end on small copper heat pipes (where the end face mates to a heat sink), TONG DA offers the TD-21025 flat-type closing machine. Both can be trial-closed for comparison.
Machine features
- Three stations cycling in turn; one operator.
- Cold forming: no heat-affected zone, no discoloration or annealing of stainless.
- Quick changeover: swap the jaw set and guide tube; the dome radius is adjusted on the machine, no mold change.
- PLC + touch screen, proximity-switch positioning for consistent closure length and hole size.
- Forced air cooling; 220–415 V, 3 phase.
Each station works independently
Every station is an independent unit. Run the same size on all stations for volume production (for example three stations on one size), or a different size on each station (three stations, three sizes) for small mixed lots. The dome radius and the hole diameter are adjusted separately on each station.
Customer track record
Since 1989, TONG DA closing machines have been shipped to gas spring and shock absorber manufacturers in Korea, the USA, Germany, Turkey, the UK, India and mainland China, with ongoing supply of jaw sets, guide tubes and hydraulic chucks. The machines are built to last: many have been running on customers’ production lines for more than 20 years and are still in stable production today.
Related: All heat pipe & heat exchanger closing machines · Spare parts
Other names by market
USA / UK / India: tube end closing machine, tube closing machine, pipe end closing machine, tube sealing machine, pipe sealing machine, tube end sealing machine, roll closing machine, roll closure machine, tube spinning machine, spin closing machine. Turkey: boru ucu kapama makinesi, boru kapatma makinesi, boru ağzı kapama makinesi, boru sıvama makinesi. Brazil: máquina de fechamento de tubos, máquina de fechar ponta de tubo, máquina de repuxo de tubos, repuxadeira de tubos. Spain / Mexico: máquina cerradora de tubos, máquina de cierre de tubos, máquina de repulsado de tubos. China: 封口机、管端封口机、旋压封口机、热旋压封口机、旋压机. Taiwan: 封管機、封口機、金屬封管機、管端封口機、管端成型機.
FAQ
Will stainless crack?
Not with normal-ductility 304/316 seamless tube or welded tube with a sound seam. For wall thickness beyond the standard range, send samples first; we trial-close and report.
Is any welding needed after closing?
No. The dome is one piece. Leak testing is to the customer’s own specification; trial samples are supplied for testing.
Copper?
Yes. Copper is among the easiest materials to close; for small copper heat pipes consider TD-21025 flat type as well.
How to send samples?
Tube OD × wall × material × length and the closed-end drawing; we trial-close and return samples.
Sealing machine to process tube require: ＊Tubes must have enough ductility. ＊Because it is a cold forming process, the tolerance will be unstable due to the factors of the pipe, and the tolerance of the incoming material will affect the overall tolerance. The tolerance of the incoming material must be as small as possible. ＊Sealing machine to process tube weld bead have to firm, when sealed weld bead will not dehiscence. ＊Outside dia less than 20mm, within length 1000mm can to install tube holder keep tube don't shake (need extra purchase). ＊Stainless steel tube hardness is softer the better and good ductility, tube material weld bead have to firm. ＊Tube outside dia and thickness have to collocation each other. Especially outside dia more than 25mm tube.
＊TONG DA reserves the right to modify technical data, design, end of delivery, color, materials, specifications and models. | ||||||||||||||||||||||||
| Three Station-Tube Sealing Machine | Specification |
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Patent Information:
Safety certification:
CE MARK
Partner company:
Sold to Germany gas spring factory , European, USA company, China, Thailand, Japanese car companies
