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Bending 1-1/2" schedule 40 seamless 316 stainless pipe.

ezduzit

Hot Rolled
Joined
Jun 27, 2013
Location
Marina del Rey, California
Have a JD-square model 32 pipe bender with electro-hydraulic power pack and die for 7-1/2" centerline radius. Need to bend 90-degrees maximum. Pipe is 0.140" wall thickness, 1.90" OD. Any problems I should expect or tips I should know about? Appreciate any help.

All comments welcome.
 

jamscal

Stainless
Joined
Sep 8, 2004
Location
Louisville, KY
I have the same bender. I think you'll be fine. Be sure to use the anti-springback function on the top...you'll probably have to.

Max on the bender is 2" od 1/4" wall dom steel, iirc, so the 1.9ish od of 1.5" pipe will have you near the upper limit with ss, I would think.

The 7.5 CLR will help.
 

ezduzit

Hot Rolled
Joined
Jun 27, 2013
Location
Marina del Rey, California
I have the same bender. I think you'll be fine. Be sure to use the anti-springback function on the top...you'll probably have to.

Max on the bender is 2" od 1/4" wall dom steel, iirc, so the 1.9ish od of 1.5" pipe will have you near the upper limit with ss, I would think.

The 7.5 CLR will help.

Thank you. Sorry, I was not notified there were any replies. Just thought I'd post a follow-up and saw yours.

The bending went extremely well, with smooth, perfect looking bends all the way to 90 degrees. And no evidence of any structural shortcomings. The only issue at all was there was so much spring-back, virtually all bends required that I heavily clamp the bender's U-shaped retainer in order to remove its pin so I could get the pipe out of the bender. Using the largest C-clamp which would fit, to take some of the pressure off the pin, I still had to pound out the pin with a 4-lb hammer.

Photos show the old, welded, piping sections and also the new replacements with their larger bend radii. I was able to eliminate all welding except for the final termination at a flange. This is a waste transfer piping system on a 213' yacht. Each of the sections shown is joined together using Staub couplings. Hangers for the system are welded in place, requiring high precision in these replacements, so they would go back precisely where the old system was located. Original piping was badly perforated due to what I believe was electrolysis.





 

LKeithR

Stainless
Joined
Sep 1, 2011
Location
Langley, B.C.
That's a really nice looking bit of tube manipulation you have there. :) :)

Yup, I agree. Been there done that--with a better bender--so I know how much work it took to do all that
and get the bends and offsets right. Question is: How much pipe did you destroy doing test bends?
 

ezduzit

Hot Rolled
Joined
Jun 27, 2013
Location
Marina del Rey, California
...How much pipe did you destroy doing test bends?

Would you believe I did not make even one practice bend? Just took my courage in both hands and started with the simple 90 degree bend. When that came out perfectly I then did the straight-ish one with the small offset, which had to be tweaked a little by slightly re-bending. Then proceeded with the one that has both a 90 degree bend plus an offset (the one with the flange welded on). The last, with all the compound bends was a real challenge and was in and out of the bender more than a dozen times, in order to get the two nearly parallel sections precisely aligned with the original.

Just returned from trying them on the boat, prior to sending out for paint. Must describe it as a perfect fit-up. Though I will cut 1/2" off the length of the one with the simple 90 degree bend, just to optimize the installation.

Here are some photos of my bender and cart, which my helper and I fabricated from an ancient Kennedy rollaway cabinet. Shown are the dies I received in my initial purchase (3/4", 1', 1-1/4" and 1-1/2" tube). Just last week added the die for 1-1/2" pipe (1.9" OD). 1-1/2" 316 stainless schedule 40 pipe seems to be the largest I can practically bend.

Thanks for the comments fellas.




 

Arc-On

Aluminum
Joined
Sep 6, 2011
Location
Holland, MI
We just did some handrails for a house on Lake Michigan out of 1.5" stainless tubing, 11ga wall. The amount of springback on that stainless is very surprising. I have bent miles of HREW and DOM steel tube, first time bending stainless of any substance. We also had to use clamps to get the damn tube out of the bender.

Parts look nice.
 

Graham Gott

Aluminum
Joined
Jan 26, 2010
Location
Denver, NC
Nice work! I imagine 316 stainless springs back like 4130. It's repeatable, just a pain to work with. I like the use of a tool box for a bender cart.
 








 
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