HOW TO CUT THE PARTS AND WELD THIS

[imagineers]

So I have a manifold made up of 1" stainless pipe, with some fittings welded onto the ends. I have a coupld questions.

1. if you see the branches the are cut in 3d to fit the long pipe perfecty, however is this how you would fabricate these branches with these weird sharp edges then weld it or is there different standard to do this?

2. Is it easier to machine the NPT ends like I have shown where the fitting fits over the pipe and is welded around in place. or better to use a butt weld end for the NPT ends similar to the triclamp ferrule on the other end.

This is a manifold for water/glyvol mix. pressure more then likely wouldnt see more than 20psi

 

[imagineers]

so basically this would be stock 1" pipe bent to the shape you see and then welded to the longer pipe which joins with 90's and 45's

 

[MikeHalloran]

1. That's pretty much how you fabricate a wye from tube.

2. Most people would weld a half-coupling on the end of the tube, and use a nipple to provide the male threads, because male threads on a welded assembly tend to get damaged in handling. Replacing the nipple is easy.

(3) If the water/glycol velocity is lower than ~20 fps, all of the fancy stuff, like smooth interior, angled wyes, is a complete waste of time and money. You could put something ugly but functional together in a few hours with threaded fittings.
Belay that; a pipefitter could do it; you would take too long.

Ignore (3) if this is an art project or somebody told you to make it look real nice.



Mike Halloran
Pembroke Pines, FL, USA

 

[MikeHalloran]

One other thing; the angle of the wyes, being custom parts, is largely arbitrary, but if you make it too acute, the welders will have to extend the tungsten electrodes out of the shield gas while doing the throat, and/or use an inert atmosphere, which adds to the expense.

Similarly, the space between the parallel tubes may present a challenge during welding, or at least limit the assembly order.

If you have a fab shop on site that welds stuff like this, you need to spend some time there, with dimensioned sketches of what you are proposing to do. Expect an earful.



Mike Halloran
Pembroke Pines, FL, USA

 

[berkshire]

Imagineers
You do not machine the edges of the saddles with a radius like you have, you leave them square to the centerline of the pipe.
So that way all parts of the connection have full metal thickness. All of the edges you have marked as sharp should be the full thickness of the metal and the hole in the main tube should allow the part to butt join at the intersection. If any chamfering is done at all it should be a prepared vee for weld penetration. The way you have drawn that ,the " Sharp" edge will just burn away if the welder has enough heat for penetration on the rest of the pipe.

Based on the problems you have/had with your tank, you need to spend time on the shop floor with the people who do this for a living ,learning how parts are assembled and welded.
B.E.

You are judged not by what you know, but by what you can do.

 

[SnTMan]

http://www.sagarfitting.com/buttwel...tting/ansi-asme-b16.9-buttweld-lateral.html#3

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[imagineers]

1. That's pretty much how you fabricate a wye from tube.

2. Most people would weld a half-coupling on the end of the tube, and use a nipple to provide the male threads, because male threads on a welded assembly tend to get damaged in handling. Replacing the nipple is easy.

(3) If the water/glycol velocity is lower than ~20 fps, all of the fancy stuff, like smooth interior, angled wyes, is a complete waste of time and money. You could put something ugly but functional together in a few hours with threaded fittings.
Belay that; a pipefitter could do it; you would take too long.

Ignore (3) if this is an art project or somebody told you to make it look real nice.

the pipes will each be running around 23L/min through them, so it is important that the transition of flow is important for pressure drop etc. I am not sure of the sizes the piping should exactly be but from the pump outlet 0.75" NPT the fluid runs into 1" lines, then all three join to go into a heat exchanger.

This isnt an art project, but I am limited by space inside the enclosure and also the overall component layout inside the enclosure. I could look at butt weld off the shelf wye type fittings then join to 45 degree pipe ends, but its very unlikely once they are welded into place the spacing will be what I need as the distance between the parallel pipes is important because of pump placemnt.

 

[imagineers]

Imagineers
You do not machine the edges of the saddles with a radius like you have, you leave them square to the centerline of the pipe.
So that way all parts of the connection have full metal thickness. All of the edges you have marked as sharp should be the full thickness of the metal and the hole in the main tube should allow the part to butt join at the intersection. If any chamfering is done at all it should be a prepared vee for weld penetration. The way you have drawn that ,the " Sharp" edge will just burn away if the welder has enough heat for penetration on the rest of the pipe.

Based on the problems you have/had with your tank, you need to spend time on the shop floor with the people who do this for a living ,learning how parts are assembled and welded.
B.E.

so do you mean cut the pipe parallel to the center pipe like in the pic attached??

 

[imagineers]

I suppose I could maybe try a lateral weld outlet, is there a standard for making one of these? Is this simply a pipe with the ends machined?

http://www.midlandfittings.co.uk/wp-content/uploads/2015/03/STAINLESS-STEEL-LATROLETS.jpg

 

[imagineers]

problem with using a laterolet is that once I get one into place with a 45 elbow my piping is too far out to line up with the pump, custom pipe may be the only way

 

[imagineers]

so I modeled up a laterolet, not sure how accurate it is for standards if one exists, it is a tricky part to model in 3D, any help on this would be appreciated. Anyhow, what do you guys think?

 

[imagineers]

Here is my new design based off mostly off the shelf parts. Ths only thing I am not 100% sure of is the modeled laterolet and the long pipe that bends for a very short 45 degree length. Thoughts??

 

[berkshire]

Imagineers,
Your weld chamfers are looking better, However when cutting a y joint into a pipe in the model you asked about, the view of the branch pipe entering at the lower right with the main pipe cross sectioned, is a better example, Imagine taking that, and making the cut straight across the pipe with a band saw, it is not quite right but would give you a better example of the penetration on the pipe.
B.E.

You are judged not by what you know, but by what you can do.

 

[imagineers]

So your saying to cut the pipe like the attachd pic? what do you think about making laterolets instead?

 

[imagineers]

so laterolet vs cut the twp pipes to match and fit it together

 

[imagineers]

The laterolet would allow a fillet weld all around? the cut pipe would require a butt weld??

 

[berkshire]

imagineers,
The cut pipe marked 2 in in your first reply Properly Vee beveled to allow for a full penetration weld is normally the way a shop would fabricate your part if they did not have commercial fittings. If you have laterolets available they will save time. However you still have to get your matching holes in your tube cut to leave a smooth edge on the inside.
B.E.

You are judged not by what you know, but by what you can do.

 

[berkshire]

One thing I note in your model is that the style of laterolet you are drawing is the one for fitting to a larger diameter pipe, yet your model shows the same size pipe. This may be where I am having difficulty understanding what you are drawing.
Look up pipe geometry for equal sized pipe intersections. or make your main pipe bigger to correspond with what you are drawing.
B.E.

You are judged not by what you know, but by what you can do.

 

[MikeHalloran]

How many of these manifolds will you be making?

At some point, it becomes cheaper to stamp it in two halves, like Panelcoil, put some spotwelds in the interstices, and do a seam weld around the outside.



Mike Halloran
Pembroke Pines, FL, USA

 

[berkshire]

Imagineers,
I am attaching a picture of what your pipe intersection should look like.
It may be less trouble for you to buy fittings like this, and just weld them into your manifold.
B.E.

You are judged not by what you know, but by what you can do.