Piping arrangements a thing of the past? 1

[DGrayPPD]

Good evening everyone,

A question regarding the use of piping arrangements (piping general arrangements, orthos, piping plans, or whatever you like to call them). Are they a thing of the past? Are they just an additional unnecessary extra cost? It was my understanding that with today's CAD software and the use of 3D models, that piping arrangement drawings do not provide the same value or benefit as they once did.

However, when I brought this point up, I was met with disbelief from other disciplines who stated that they did not understand how a project could be built without them. I told them that with the use of 3D models, a contractor had the ability to see the entire project and the ability to pan around at all angles to understand the arrangement better than a plan view of the piping. The response I received was, "Contractors do not always have computers or laptops with them."

In today's day and age of technology I found it hard to believe that contractors do not have the means to view a 3D model, whether by laptop or on-site office. That does not, however, mean that I am right. I could very well just be making a wrong assumption. So I would like to hear other opinions on this subject. Are piping arrangements a thing of the past? Or are they still commonly used?

Thanks for all the input.
Dustin

 

[MikeHalloran]

The guy carrying wrenches on his belt is not going to appreciate having to carry a laptop around, nor will he appreciate trying to see the image on the screen on a sunny day, and he will probably never get used to seeing his world through that tiny aperture.



Mike Halloran
Pembroke Pines, FL, USA

 

[DGrayPPD]

I understand that. I found where the basis for my question evolved. The arguments in this forum made sense to me, but I figured more opinions wouldn't hurt.

http://pipingdesigners.com/forum/the-technical-forum/1972-piping-orthos

Thank you for your insight Mike.

 

[PEDARRIN2]

The use of 3d models will (and do) work well in the contractor's office or trailer for coordination and visualization.

But on a cold winter day when the building has not been dried in yet, and the wind chill is below zero, I cannot see a contractor, who can barely feel his fingers without his gloves, maneuvering the mouse to follow where the piping is supposed to be.

2d plans will never totally go away.

 

[moltenmetal]

In our shop environment, we have our fabricators use the model directly to visualize the routing and location of lines relative to one another. But they still build from a paper copy of the isometric drawing, and always will.

In a field environment, they will still need a routing drawing, or at least a printout of a screenshot from the model with the line highlighted- it is incredibly valuable in visualizing how things are supposed to go together.

 

[LittleInch]

Are they a thing of the past?? no - not in design output terms. Creating / modifying the design, sure 3D models are great and allow better visualization and ability to avoid clashes, trips and head hazards, improve operability and access to valves etc, but it is difficult to issue as a deliverable ( and sign) and almost impossible to note changes and modifications and create revision control.

As for all those v important Notes on drawing - where do they exist in a model??

In the main site office / accessible from the filed its great to use to solve site issues and provide some guidance, but not as use for site construction.

IMHO.




Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[DGrayPPD]

Just to be clear, I am not talking about ISOs being a thing of the past, only piping plans/arragnements.

 

[pennpiper]

DGray,
You wrote: "Are piping arrangements a thing of the past? Or are they still commonly used?"

The answer to your question is actually both Yes AND No!

Very Large Projects for Very Large Clients done by Very Large Engineering Companies can and will lean toward not using Piping Plans and Sections and will install a 3D Work Station at the Jobsite.

Smaller projects done for any size Client done by Small to Medium sized Engineering Companies will still lean toward producing Piping Plans and Piping Section Drawings.

What drives this issue on projects?
- Money! How tight is the Clients Budget?
- Project Type! Is it a Grass Roots/Green field Project or is it a Revamp of a real old plant?
- Project Execution! If the Project is all Sub-Contract Construction, the better the Documentation the simpler the management.


Sometimes its possible to do all the right things and still get bad results

 

[DGrayPPD]

Can anyone provide a break down on what information is important on a piping arrangement?

And are piping arrangements mainly done in a plan view? How often are piping arrangements seen in an elevation view?

Thanks
DGrayPPD

 

[pennpiper]

Arrangement Drawing is an improper term for a Drafting View of an object.

In Piping the Proper term is Piping Plan and where required Piping Section.

Now is that so hard?

Sometimes its possible to do all the right things and still get bad results

 

[DGrayPPD]

My apologies.

 

[DGrayPPD]

Reason I am asking is because I have some, with little or no piping background, who think that 3 views should be given on a piping layout drawing. The 3 views being:

1) Plan View
2) Elevation View
3) Isometric View

Based on my research and the book "The Planning Guide to Piping Design," page 82 states, "piping arrangements (as it is written in the book) should be minimally detailed and dimensioned, and as far as possible, be limited to plans only. Partial sections and details should only be required when a congested area or some vertical detail cannot be clarified in any other way."

In my current situation, the client has left it up to us to come up with the piping layout drawings and I am just trying to follow the best and most common industry practice, while also eliminating unnecessary extra man hours. My area is not congested, and I don't understand the point of having an isometric view if we are providing piping isometrics already.

I would just like some outside opinions from experienced pipers before pursuing the argument further.

 

[Gator]

It sounds like someone is referring to a single drawing of a smallish (for example) vendor equipment skid that has accompanying piping on it or perhaps a drawing of single, relatively simple piping module (which is to be later assembled on site as one-of-many) that includes an isometric view for visualization purposes.

These days, the "arrangement drawings" effectively function as an assembly guide of sorts that can be marked-up in the field. As opposed to the old days when you'd draw the orthographic piping first, and then draw the fabrication isometrics from there.

Piping plans and elevations don't need detailed dimensioning anymore, assuming the isometrics are being extracted from a 3D plant model.

Thanks for buying the book. I obviously don't disagree with what it says.

 

[pennpiper]

DGray,
I agree with this:
Based on my research and the book "The Planning Guide to Piping Design," page 82 states, "piping arrangements (as it is written in the book) should be minimally detailed and dimentioned Based on my research and the book "The Planning Guide to Piping Design," page 82 states, "piping arrangements (as it is written in the book) should be minimally detailed and dimentioned, and as far as possible, be limited to plans only. Partial sections and details should only be required when a congested area or some vertical detail cannot be clarified in any other way and as far as possible, be limited to plans only. Partial sections and details should only be required when a congested area or some vertical detail cannot be clarified in any other way."

And if you are doing an Isometric of each line then you do not need to prepare an Isometric View of the total project/Skid//assembly.

Do it once and do it right. Do a good and proper job but don't run up the cost unnecessarily.

Sometimes its possible to do all the right things and still get bad results

 

[adammal44]

In my experience (nuclear power plant piping), the experience is similar. For large portions of piping (and associated equipment) that we are fabricating offsite as a piece (module), we provide both the basic isometrics and larger arrangement drawings (showing valves, tanks, piping, etc.). We also do it for key areas, as it supports a variety of other analyses that require a configuration control pedigree that cannot be achieved by a 3D model(maintenance and in-service inspection plans, radiation shielding, subcompartment pressurization). Other than these things, isometrics are all we do for piping and (significant) tubing.