Previous in Forum: Contra Rotating Axial Fans   Next in Forum: Turbine
Close
Close
Close
15 comments
Active Contributor

Join Date: Jan 2012
Posts: 10

Fittings for a Stainless Steel Pipe

02/23/2012 7:15 PM

I would like to rotate a 6" stainless steel pipe (24" long, Schedule 80, T-316) via power applied to a 2" or 3" steel pipe, at a torque level of 1,000 ft-lbs. Specifically, I would like to insert the smaller pipe through the 6" pipe and attach them via a bushing or flange at each end, but I cannot locate fittings that match up. Machine operations like threading or drilling are OK, but I would hope most of the parts are commercially available T-316.

Any ideas are welcome.

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 31553
Good Answers: 1744
#1

Re: Fittings for a Stainless Steel Pipe

02/23/2012 8:17 PM

Why not just use some 1/2 steel plate cut to shape and weld it? I might contact somebody that makes drive shafts for assistance or google drive shaft fabrication for a shop near your location.

__________________
Break a sweat everyday doing something you enjoy
Register to Reply
Power-User

Join Date: Dec 2010
Posts: 377
Good Answers: 20
#2

Re: Fittings for a Stainless Steel Pipe

02/23/2012 9:17 PM

Your Pipe ID is 146.2mm or so and 2 inch 150# flange OD is 152.4mm. You can use 2 inch flanges either after threading on the OD and matching thread on ID of the pipe or after machining the Pipe ID to 152.5 and insert the flange and weld it at the edges , or lock it from the sides.

Register to Reply Score 1 for Good Answer
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21001
Good Answers: 781
#3

Re: Fittings for a Stainless Steel Pipe

02/23/2012 10:07 PM

Probably the simplest would be to make two plates with O.D. to fit inside the 6" pipe, and I.D. to fit over the 2" or 3" pipe. Conveyor pulleys are often made this way.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Active Contributor

Join Date: Jan 2012
Posts: 10
#14
In reply to #3

Re: Fittings for a Stainless Steel Pipe

02/29/2012 2:17 PM

Perhaps this is the way to go, with a bolt or clevis pin to convey the torque. Thank you for the reply.

Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#4

Re: Fittings for a Stainless Steel Pipe

02/26/2012 12:43 AM

Drive shaft end flanges need to be welded on not screwed.

What are you building John?

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Active Contributor

Join Date: Jan 2012
Posts: 10
#5
In reply to #4

Re: Fittings for a Stainless Steel Pipe

02/26/2012 4:59 PM

The 6" pipe will wind a cable of a boat lift.

What are the pros and cons of welding vs screwing?

Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#6
In reply to #5

Re: Fittings for a Stainless Steel Pipe

02/26/2012 8:42 PM

You are building a capstan/drum winch.

Welds can't loosen ie unscrew.

If screw together is easier for you for what ever reason then you will have to tack weld the threads so they don't unscrew. If you need to dismantle you can grind the tacks off and unscrew.

With welding you aren't constrained to available thread sizes and possible design compromises. You can make it the size you want not the size that's available.

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Active Contributor

Join Date: Jan 2012
Posts: 10
#7
In reply to #6

Re: Fittings for a Stainless Steel Pipe

02/27/2012 11:42 PM

How about Tornado's solution, which involves two annular rings (he calls them plates) that fit between the two pipes. The pipes and the rings can be through bolted to make them rotate together. I do not know the cost of making those rings, however, and that can change the picture.

Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#8
In reply to #7

Re: Fittings for a Stainless Steel Pipe

02/28/2012 7:39 AM

Bolt through would work but may clash with other parts. This method of securing is prone to hole elongation and increased lash over time...could even break the bolts if they wear thin.

A clevis pin would keep things turning together securely with easy dismantling but you will have to get keyways milled into the shafts and collars.

I haven't quite pictured the arrangement. Can you post a sketch?

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Active Contributor

Join Date: Jan 2012
Posts: 10
#9
In reply to #8

Re: Fittings for a Stainless Steel Pipe

02/28/2012 12:01 PM

The problem of hole elongation and lash could be reduced by increasing the diameter of the bolt. Here is what I now have in mind. The sketch shows just one end of the drum. The main question with this, I think, is the cost of the ring. Any thoughts?

Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#10
In reply to #9

Re: Fittings for a Stainless Steel Pipe

02/28/2012 9:31 PM

Cost to fabricate (turn) the ring?

In these parts $10 labour plus material at metal spot price.

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Active Contributor

Join Date: Jan 2012
Posts: 10
#11
In reply to #10

Re: Fittings for a Stainless Steel Pipe

02/28/2012 10:24 PM

Well that is right on, Guru. Thank you.

Of course I must adjust for "in these parts," to "in my parts" since I see that you are in Phnom Penh and I am in Florida. How many machining hours are in the $10. labour? I can easily adjust hours to local rates.

If this goes into production, of course, I may be back in "your parts" again.

Register to Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#12
In reply to #11

Re: Fittings for a Stainless Steel Pipe

02/29/2012 1:04 AM

Machine shop here charges per job not time.

Not including shopping time for material that would take an hour or 2 to turn on a lathe.

__________________
Difficulty is not an obstacle it is merely an attribute.
Register to Reply
Active Contributor

Join Date: Jan 2012
Posts: 10
#13
In reply to #12

Re: Fittings for a Stainless Steel Pipe

02/29/2012 12:08 PM

Thanks to you and to all the others who have contributed to this discussion.

Register to Reply
Guru

Join Date: Jul 2007
Location: Commissariat de Police, Nouvions, occupied France, 1942.
Posts: 2599
Good Answers: 76
#15

Re: Fittings for a Stainless Steel Pipe

03/10/2012 4:56 PM

Why not make the outer part an interference fit on the inner part, then heat it, insert the inner part and let it cool? The process is called shrink-fitting.

__________________
Good moaning!
Register to Reply
Register to Reply 15 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Crabtree (1); John Bellantoni (6); Mukesh0861 (1); SolarEagle (1); Tornado (1); Wal (5)

Previous in Forum: Contra Rotating Axial Fans   Next in Forum: Turbine

Advertisement