New technology for fabrication / installation of small diameter pipes 8

[corem16]

Good morning,
My name is Thiago Mello, I am an mechanical engineer specialist in piping from a big company in Brazil and I have a huge problem that I like to share with my professional colleagues.

Our company, which is specialized in Downstream, has several capital projects being implemented. It had been identified that fabrication and installation of piping systems represents 40% of the amount of workmanship in a petrochemical project, and, to be more specific, fabrication and installation of small diameter pipes had been causing problems to our schedule projects (because of great quantity of welding that have to be done), due to the fact that is always the last to be installed. I would like to know if there is any new fabrication or installation process that could be more productive?

I would like to hear comments/suggestion from you.
Regards.
Thiago Mello

 

[StevenHPerry]

There's nothing new or revolutionary that I'm aware of, but there are some things that might be considered out of the box.

1) mechanical joints like Victaulic or TriClamp.
2) skidding as much small bore as possible.
3) spending the $ to engineer things right the first time (multi-discipline 3d computer models, optimized erection sequence).

In my experience dealing with "big compan[ies]" "specialized in Downstream", it's an uphill battle for the likes of Victaulic on any service besides potable water. Skids have proven successful if you can block off the footprint early on in the design. Engineering it right the first time has almost always been curtailed in favor of schedule. Some times that is justified, but haste tends to make waste.

Be ready for some serious "discussions" with the folks who have done it the old (ne, the best!) way for years and years.

- Steve Perry

 

[moltenmetal]

Maximize the use of modular construction in a factory environment (i.e. "skids" rather than site-built construction). This allows parallel fabrication at multiple facilities with fewer log-jams on site.

Consider that it may not be the welding itself that is entirely to blame for how long it takes to install welded piping. If you're applying some crazy blast + primer, mid-coat and top coat paint system to small-bore pipe, the same as what you'd use for large process lines, give your head a shake and consider using stainless instead- unless you're also painting stainless out of CSCC worries...

Socket weld 2" and smaller, if your specs don't already permit that.

Threaded + Victaulic make sense for many utilities except steam/condensate. Threaded gets a bad rap but with a good sealant system it's very reliable.

 

[pennpiper]

Corem16,
You wrote:
"to be more specific, fabrication and installation of small diameter pipes had been causing problems to our schedule projects (because of great quantity of welding that have to be done), due to the fact that is always the last to be installed."

Some people may have the same idea of "Small" and some may not when it comes to piping.
I have worked in a place where 4" and smaller was considered "Small Bore Piping" and I have worked in a lot more places where 2" and smaller were considered "Small Bore Piping".

What is the size break for your projects?
and
Are you using Socket-welded piping for the 2" and smaller?

Why is "the great quantity of welding" suddenly a concern?

 

[corem16]

Pennpiper, I consider small bore piping below 4" NPS, but I agree with you about the multiple understanding when it comes to small diameter pipes.

We consider welding a concern because our contractors have a culture to use SMAW as the main welding process, and we don't have enough specialist workmanship to other process more productive like MIG/MAG, FCAW.

In fact, our sector is responsible for new technologies regarding fabrication and installation in different subjects, but always focused in refinery plants.

I made some research in the internet and I have identified two process that could succeed in a near future:
First would be the use of induction bends process for spool fabrication in order to minimize welding in the installation (I think this is the way to modularize or skidding, like Moltenmetal and StevenHpPerry said previously, is that right?.

Second would be the use of spooled flexible piping system, similar to offshore riser reel. This could be supplied in long lengths spooled onto combined shipping/installation reels. This means that this method can be very quickly and cost effectively installed by a number of methods (see link:

http://www.flexsteelpipe.com/MS_6.html

).

I would like to hear comments/suggestion from you.
Regards.
Thiago Mello

 

[pennpiper]

Where (in general) are these projects you are talking about?
and
What is the percentage split between:
Shop Fabricated Piping?.....(What are the sizes?)
and
Field Fabricated Piping?.....(What are the sizes?)

 

[corem16]

Pennpiper,

The projects take place only in Brazil and I don't have the figures that you are asking...

We are working, in this first phase, with general technologies that could be applied in most projects.

Best,
Thiago

 

[StevenHPerry]

Thiago,

By skidding, I mean putting a particular system on a small platform. Everything within the skid is done 100% in a shop environment. The skid is then picked up, transported to the installation site, dropped in, and connected. No small bore piping to be done except the final tie-in welds (but preferably flange bolt ups).

This can be done with standard fittings, no need for pipe bends, flex pipe, or hose.

See this website for a general idea.

http://www.pipingsolutionsinc.com/

Take lube oil supply for a compressor. You could buy all the components piece-meal, locate them all on your plot plan, design & engineer the piping component-to-component and component-to-compressor, buy shop spools, make field welds, and do the inevitable field adjustments. Or you could box out a 10' x 10' square for a vendor to provide you with all equipment necessary. You just need tie-ins for lube oil supply and return (plus any utilities needed).

- Steve Perry

 

[europipe]

In addition of the comments above (and I'm not related to) you can also use Lokrings to reduce fieldwelds.
Like that system.(More secure than Victaulic)

Greetings

 

[moltenmetal]

Lokring and Vic PressFit are both ways to trade labour cost for fittings cost. Both systems also take up a lot more space than welded fittings do. Whether it's economic to use them or not depends on your labour productivities and what price the vendor is charging for the fittings. In a SHOP environment, where labour productivities are relatively high, both of these systems fail to actually save any money when compared with truly comparable conventional pipe specs in our experience. For field connections especially in a hot-work permit environment, these systems certainly have their advantages.

While we routinely bend TUBING for use with compression fittings, we rarely bend pipe merely to save welds around elbows. We bend when long radii are necessary for process reasons, and when welding is particularly troublesome or expensive.

 

[corem16]

Montemmetal,
You said previously "...comparable conventional pipe specs in our experience.".
What did you mean? Do you have a comparative study between welding vs weldless fittings?

Regards.

 

[DSB123]

corem16,
You open up your post with "I am a mechanical engineer specialist in piping from a big company" so if you are a "specialist" should you not know the best way forward for fabrication of pipework? From your postings it appears the problem is the quality of your potential labour force. If that's the case possibly the best way is to either train the existing labour or "buy in" better labour from outside of Brasil.

 

[moltenmetal]

What I meant is that Lokring should be compared with SOCKET welded piping, and Press-Fit should be compared against THREADED piping.

If you compare Victaulic Pressfit against socket- or butt-welded piping, of course it saves labour which pays for the extra cost of fittings- but it is NOT equivalent in terms of fire safety, robustness against external damage, solvent resistance etc. etc. Compared with threaded piping it saves nothing whatsoever, while also being less flexible to alterations/changes and taking up far more space than the same assembly made from threaded fittings.

 

[StevenHPerry]

Victaulic sent a demo team by my office today. To summarize their sales pitch:

Victaulic is great for utility services. See category D in B31.3. The material cost is greater, but the labor savings are two-fold. 1) much faster and 2) much less skill required.

Victaulic's people did the equivalent of 24 linear inches of welding with their couplings in 2 minutes. This was on a test setup with pre-grooved pipe and with people who've practiced this same demo every other day for a year though.

Pressfit pipe is, they claim, much easier to field route than screwed pipe.

Pressfit's sweet spot is 1.5" and larger systems that would otherwise be screwed pipe due to the difficulty accomplishing leak-tight connections with threaded pipe.

My thoughts concerning the lesser skill requirement: welders are paid a premium for the unique skill and (often) equipment that they bring. There's also the risk they run of busting x number of welds and being thrown off the job. Putting the welders on the critical pipe and just some muscle on the victaulic piping is a smart move. However, a competent pipe fitter is always necessary. Vict. coupling, press fit, screwed, or welding. A quality fitter will save you time and material.

- Steve Perry

 

[corem16]

I appreciate all information that you gave.
We will analise all of them.

Thanks.
Thiago