Snap Fit Arrangement for Tubing

I have a good idea of what you need; are you planning to weld after 'snapped' into place or is this taking place of the weld, does the joint have to be inflexable-rigid or is it a loose fit?

How about some idea of the dimensions and the wall thickness of the tubing.

I see a slot in the tube and a proud locking feature on the bulkhead, but you could go the other way around.

You may want to check the Magnaform process. It shrinks the outer tubing onto the cylinder using pulsed magnetic discharge. Takes a few milliseconds per joint.

Can you tell us what your proposed applications are for this process?

The Application of this product is in Combustible Gas areas. The Temperature will be around 300 - 400 Deg Centegrade.

The press fit which i am looking will replace existing welding & it will be a Rigid (Nonflexible) Air tight joint.

Does the Swaging operation give the Air tight joint?

Also does the Magneform process is useful for SS material joining application?

The SS pipe diamete is around 42 mm x .9 mm thick.

Please put your valuable thoughts.

At the high temparature, you are suggesting and also to get an air tight joint there is no other efficeint method than welding.

It being a combustible gas area, we do not expect you to take chances since you need a fool/leak proof joint which can be obtained only by welding.

May be you can adopt a better/easier welding process. This can be thought of with more information like dimensions, type of material etc. Sridhar.

I agree you can not get a leak proof joint without welding, especially at the temps you are running, although if you still want a snap fit for fixturing before the weld you could make treaded ends or mail female ends or use a bubble snap. you still have to weld unless you can find a glue that will withstand the temps you will be using and I would only use that on the threaded ones-check out silicone for replacing glue on theads.

I suggest you contact http://www.Magneform.com with specific questions regarding their process, but yes, SS tubing will work. There is another option of projection welding the tube to the flange. This is a low cost, high speed welding process that can be used with most of the 300 series stainless steels. It would requre that you redesign the joint, either by swaging the tube end to provide a flange, or by providing a taper on the side of the cylindrical plug.

There is a plumbing solution that may work for You. It requires a special fitting that slips over both pieces and then is crimpt with a hydraulic device.

oilcan13

The crimp usually has some sort of rubber that will make the seal.

Might be a little too hot for rubber.

"The Temperature will be around 300 - 400 Deg Centegrade."

instead of rubber silicone will take more heat.

For that temperature and combustible gas, I don't see why not welding. Other option may be costly, going for compression fittings (Contact Swagelok or other suppliers of compression fittings) your size may be on the extreme end of their catalogue (I think they supply upto 2" and also metric)

But how to fit that orifice ?

I think welding the parts is the best way to join them an be 100% sure that they can do what you require at the temperatures you stated. I really don't see a complex weld problem here. A small rotating welding positioner/jig to hold and turn the parts and a simple automated GMAW or GTAW welding source. You could probably get a good joint without having to add filler metal and just fuse the pieces together with a GTAW or pulsed GTAW. I have built automated welding contraptions to make small cylindrical parts a few times in the past when the need arises. I built one once to weld items that were too thin for me to manually weld quick enough to not burn the parts up and ruin them. I used a homemade variable speed DC motor welding positioner to turn and hold the parts and a GTAW head and a couple of relays to start and stop the welding. I joined many hundreds of the little parts I was building with pretty good success and very little expense. I may be telling you something you already know here but I don't see why you have a weld problem and wonder what method of welding and fixturing you are currently using? I think that using any mechanical means to join the two parts would be allot more complex and expensive than welding.

I agree with pipewelder's advice. I suspect you have been exposed to some inefficient welding technologies. With some form of fixtured GMAW or GTAW welding you should be able to weld about 30 pieces/hr. With a projection welding system you could probably weld about 300 assemblies/hr.