Install pipe in vertical shaft

[gravitate]

We have 2 stainless DN 600 pipes to go side by side in a 750 x 3500 shaft. Is this space too small to install the pipe in sections welding every 6m or would it be preferable to get the pipe delivered while the building is in construction and lift the pipes in 1 length then weld at the top and the bottom?
The rest of the space in the shaft will be used for HVAC but if the pipe is early and lifted in 1 go then the HVAC will not be there.
I find it hard to imagine the space restrictions as the building is not built yet.
Thanks

 

[MikeHalloran]

I don't think you have room to weld the circumferential joints in situ.

I suppose you could build it from 6m or random lengths, welding at the roof, and winching it down the shaft as it's built, then do the bottom weld. You would want to check that the roof has space to work and strength to support the pipe and the hoist, and that you can get welding power up there. You also have to thread the pipe through any intermediate supports, or build them around the pipe.

Or you could build the entire pipe on the ground on site (having space to do that should not be assumed), then hoisted and dropped in. ... you need a very tall crane to do that.

Do you need to weld the joints? I.e. could you use groove-joint couplings, like Victaulic or similar? You need to check, but there may be room to insert, engage and tighten them within your shaft, given a few handholes.



Mike Halloran
Pembroke Pines, FL, USA

 

[Latexman]

Also, you need to think about what to do in the future if the pipe starts to leak or fails? Is this design sustainable?

Good luck,
Latexman

Need help writing a question or understanding a reply? forum1529

 

[dvd]

What aspect of the shaft is 750 x 3500 (assuming mm): top to bottom, totally enclosed; or just the floor penetrations? If it is just the floor penetrations and you get there before firewall is installed, then you may well be able to make the welds.

 

[gravitate]

Hi sorry you are right the shaft between the levels is 2014*3350 so yes I do think there is enough room to get in there and weld. My only concern now is that the pipe is very close to the side of the shaft

 

[LittleInch]

Gravitate,

You actually haven't given us much to go on so a sketch would be useful to you and us to see what is your issue. You say the building is not built, but clearly have plans available

how high is the building?? How are you fixing the pipes to the shaft?? does the pipe need to take the full vertical weight at the bottom at any time or is it clamped at regualr intervals?? why is it stainless?? Are there any connections or is it a simple pipe from bottom to top??

You will need about a metre all the way round each pipe to weld, especially Stainless which usually needs bottle of argon as well as the usual welding apparatus or a thin compliant welder. You also need plenty of ventilation and need to guard others from the welding arc. Your space between the levels still look too small, especially after one pipe is installed / welded. Even if the pipes are the only thing there and central, there is still only 750mm space - very cramped for a welder to work safely. As soon as anything else turns up in the shaft you won't have enough room to weld.

I can only assume you can lift each pipe in vertically as otherwise I don't think they are going to fit. if you can do this then it would seem your only decent option is to lift pipes in one at a time at the top fo the shaft, then weld up, unclamp, lower in, clamp and repeat.

You need to consider if welding is required or, as MH says above, other forms of jointing could be used. If you can rotate the pipes, then screwed couplings become feasible and need much less space to construct.

Are you designing this or simply trying to construct what someone else has designed without doing prper analysis of how to construct it? what sort of freedom do you have to modifty things?

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[racookpe1978]

IF (Big IF there!) there is only one area of the pipe that is close to a wall, then a good welder can work that part of the weld with 6 to 8 inches clearance. (150 mm to 200 mm). 4 inches (100 mm) is doable - but it will be slow work and some welders can't manage it. (When I have to work with less than a 3-4 inch gap (76-100 mm) I usually use a smaller TIG rig or micro torch: they have reduced cup lengths and reduced clearance tungsten heads as well.)

BUT that assumption requires that most other areas of the pipe DO allow access around the pipe.