Method to design a big concentric reducer 1

[9Mech]

Hi everbody

I hope someone can help me in this problem

I have a a carbon steel pipe that needs to be reduced
from 60" to 56", for gas Service 150#

Since is difficult to find on the market
this kind of Reducer, the only option
in urgency for me is to build it.

-Does anybody have a method to design and build in field
this fitting (sketch showing how many cuts, cut angles, length, etc.)?
(similar method found for mittered elbows?

-Is this practice allowed by code?

Thanks

 

[C2it]

Design of a large reducer is covered by ASME VIII Div. 1.

You need to comply with whatever local or State design codes exist.

 

[9Mech]

Ok designing under that code in order
to get thickness,is OK.

But I´looking a method to build it at shop

(Shop sketches)

Thanks

 

[btrueblood]

What kind of equipment does your shop have? What thickness do you need, or what pressure must be contained? What maximum sheet/plate width can you obtain/handle/shear/cut? What material? Do you want my fitting design to also show best layout for material usage?

If the above sound a bit like what a design engineer likes to be paid to do, good - that makes 2 of us.

 

[DSB123]

9mech,
As btrueblood says either do the investigation into fabricators capabilities in your area and prepare the design documentation(incl drawings, material specs, weld information NDT requirements) yourself or pay a competent pressure systems engineers to do the necessary work.

 

[9Mech]

Btrueblood and DSB123

Sure, I have not explained clearly the point.

The case:

In the field, we need to connect two pipes
one 60" to other 56", so we need a reducer.
Is process gas 150# 160 Degrees Farenheit.
the thickness is 0.75"

With the unavailability for such reducers
with my providers.

Can this be made in the field?

I mean, to have a pipe, make longitudinal cuts around
then to joined them, welded and thats all.

If can be done with mittered elbows, why can´t be done with reducers?

How is solved a case like this in industry?


Thanks

 

[DSB123]

9Mech,
C2it has already indicated which Code may be used to "design" the reducer. The reducer itself must be formed by rolling plate of required thickness (taking rolling tolerances into consideration) and butt welding probably two horizontal seams to connect the two rolled sections together to form the cone.

 

[9Mech]

Thanks DSB123

What you said sound OK.

So the way I thought is not the usual way

Formed from a piece of pipe?

Sorry I´m newbie as a Mech designer


Thanks

 

[europipe]

9mech,
In 'the old days' they didn't care much about codes and standards,
they used their calculations, common sense and workmanship.
I think You have a great idea to make cuts at the end and taper it and weld it.
When it's properly done(and it's only a 150# system),it's okee.

Greetings

 

[LUDPEKA1]

Search on the web for “The pipe fitter’s and pipe welder’s handbook” by Thomas W. Frankland. It describes what you are looking for. Now if it meets current codes? I can’t help you with that.