Flue pipe compression ring for stabilisation of the bottom end of roll-up flue pipes. The ring has an additional snail-tail that can be interlocked with the overlapping flue pipe seam to prevent it from falling out once the outer flue pipe holding ring is tightened around them..

Introduction

Roll up flue pipes or stove pipes are often used with backpacking tent stoves. The bottom end of the pipe needs to fit closely into a round hole in the stovetop. At the same time, there needs to be some device to stop the flue pipe falling into the stove body. Permanently fixing such a device to the flue pipe will spoil its roll-up characteristics. Equally, a fitting on the flat stove top will spoil the flat and benign finish for a back-friendly load. I have already described an easy fit conical stove connector that can help to solve this problem. For this fitting to work optimally it requires a compression ring within the bottom of the roll-up flue pipe to ensure that it does not collapse inwards and fall through the cone. The problem that I had with this ring was that it was easy for it to fall out into the stove body and become ineffective. In this post, I describe a simple modified compression ring that can mesh or interleave with the flue pipe overlap of a roll up flue pipe. It can be locked in place with one of the regular flue pipe holding rings.

Flue pipe holding rings. These rings hold the shape of roll-up flue pipes for ultralight backpacking. They weigh about 1.3g each and have high visibility if dropped on the ground.
Flue pipe holding rings. These rings hold the shape of roll-up flue pipes for ultralight backpacking. They weigh about 1.3g each and have high visibility if dropped on the ground.

The snail-tail flue pipe compression ring

Flue pipe compression ring for stabilisation of the bottom end of roll-up flue pipes. The ring has an additional snail-tail that can be interlocked with the overlapping flue pipe seam to prevent it from falling out once the outer flue pipe holding ring is tightened around them..
Flue pipe compression ring for stabilisation of the bottom end of roll-up flue pipes. The ring has an additional snail-tail that can be interlocked with the overlapping flue pipe seam to prevent it from falling out once the outer flue pipe holding ring is tightened around them. The match stick is there to hold the snail-tail open so that it can be seen.

The compression ring in the above case is ~45mm tall and weighs ~8g. It could be considerably longer and act as a sacrificial flue pipe protector, to protect the flue pipe from the ravages of the heat that normally attacks this part of the pipe.

The ring is welded from a strip of metal that is~30mm longer than the piece that would have made an equivalent simple compression ring. It has an outside diameter that is equal to the inside diameter of the holding rings. This means that it can be easily put inside the flue pipe and its tail can be interleaved with the flue pipe seam overlap. The two parts become locked together when the holding ring is slipped down until it is tight.

Discussion

The lightweight and packability of this component make it ideal for backpacking. The compression rings precise diameter is less than the flue pipe holding rings ID. Consequently, the compression ring can be efficiently stored beneath the multiple flue pipe rings on a snail-tail-rolley that I use to roll up the flue pipe and store it for backpacking. This means that the ring does not add any extra volume to the stove for backpacking.

If the compression ring was to also be used as a sacrificial protector for the flue pipe it could, for example, be as long as the snail-tail-rolley. In this case, the rolley could be the compression ring. However, it would be prudent to have one of each while the longevity of the compression ring is evaluated.

“It is a tough existence in the bottom end of a flue pipe at the best of times and it is the bit that will sooner or later need to be cut off to restore quality to the end of the pipe. Putting a protector in there is likely to ‘save’ the flue pipe, but the insulation provided by the flue pipe that is covering the protector will hasten the demise of the protector! Does this sound perverse?”

Tim

gge

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