Need a coupling for SS tubing with same OD as the tubing
Need a coupling for SS tubing with same OD as the tubing
(OP)
Guys I need a way to screw together short sections of 1/2" or 3/4" SS instrument tubing, each section being 4' long or so, and subject to the following constraints:
1) The OD of the coupling or connector must be the same OD as the tubing, i.e. a standard pipe coupling or pipe collar won't work
2) The ID must be open to pass liquid
An example would be the way that a rifle cleaning rod screws together - it has a smooth and flush OD at the coupling. These are not hollow though so the example stops there.
The coupling must be the same OD as the tubing because the entire assembly must pass through a packing gland. Do any of you know if a coupling/connector like that is commercially available? The Swagelok people were no help.
1) The OD of the coupling or connector must be the same OD as the tubing, i.e. a standard pipe coupling or pipe collar won't work
2) The ID must be open to pass liquid
An example would be the way that a rifle cleaning rod screws together - it has a smooth and flush OD at the coupling. These are not hollow though so the example stops there.
The coupling must be the same OD as the tubing because the entire assembly must pass through a packing gland. Do any of you know if a coupling/connector like that is commercially available? The Swagelok people were no help.
Thanks!
Pete





RE: Need a coupling for SS tubing with same OD as the tubing
If push comes to shove: calculate the wall thickness you need, get SS bar stock, bore through and thread it(male and female.
On the female side you may want to machine a groove for an O-ring at the end, don't do it at the end of the male portion if the o-ring is flushed by the flow you'll probably damage something.... but again you may have thought of this yourself.
All the commercially available connectors I know have an OD bigger than the OD of the instrument tubing.
Good luck
Saludos.
a.
RE: Need a coupling for SS tubing with same OD as the tubing
RE: Need a coupling for SS tubing with same OD as the tubing
RE: Need a coupling for SS tubing with same OD as the tubing
Yes this does need to be disassembled in the future. This is a cleaning lance for the on-line cleaning of an in-service low-pressure 16" line. The idea is to hook the end of the lance to a pressure washer, insert it into the packing gland, turn on the pressure washer, and then screw on more sections as needed. The max length needed is about 16' or so, so I would be screwing together three or four 4' long sections.
I thought about machining a fitting but the threads would have to be tapered to get any kind of an ID. A taperd thread would make a really thin section at the thread root and this has to hold 4000 psig or so. I still need to do the calcs - it might be OK since the tubing ID is only 3/4".
Thanks!
Pete
RE: Need a coupling for SS tubing with same OD as the tubing
Yes this does need to be disassembled in the future. This is a cleaning lance for the on-line cleaning of an in-service low-pressure 16" line. The idea is to hook the end of the lance to a pressure washer, insert it into the packing gland, turn on the pressure washer, and then screw on more sections as needed. The max length needed is about 16' or so, so I would be screwing together three or four 4' long sections.
I thought about machining some fittings, as was suggested, but the threads would have to be tapered to get any kind of an ID. A taperd thread would make a really thin section at the thread root and this has to hold 4000 psig or so. I still need to do the calcs - it might be OK since the tubing ID is only 3/4".
Thanks!
Pete
RE: Need a coupling for SS tubing with same OD as the tubing
Yes this does need to be disassembled in the future. This is a cleaning lance for the on-line cleaning of an in-service low-pressure 16" line. The idea is to hook the end of the lance to a pressure washer, insert it into the packing gland, turn on the pressure washer, and then screw on more sections as needed. The max length needed is about 16' or so, so I would be screwing together three or four 4' long sections.
I thought about machining some fittings, as was suggested, but the threads would have to be tapered to get a large enough ID through the coupling. A tapered thread would make a really thin section at the thread root and this has to hold 4000 psig or so. I still need to do the calcs - it might be OK since the tubing ID is only 3/4".
Thanks!
Pete
RE: Need a coupling for SS tubing with same OD as the tubing
RE: Need a coupling for SS tubing with same OD as the tubing
RE: Need a coupling for SS tubing with same OD as the tubing
Thanks!
Pete
RE: Need a coupling for SS tubing with same OD as the tubing