Revit 2023 Demo Piping Auto Connections

[jhendrickerBGPNW]

I'm running into an issue where I have demolished piping that is at a certain elevation and then try to route new piping at the same elevation, the new piping automatically connects to demolished piping whenever it crosses it if ran at the same elevation.

I attempted to create an intermediary "Demo" phase to put the demolished piping on, and the issue persisted.

I'm assuming others have run into the same issue. Has anyone figured out a good work-around for this?

[hmunsell]

Interesting.... I opened 2023 to verify and Yep, it placed a Tee even though the pipe is Demo'd and my view is set to New Construction / Previous + New. I pull up an older version of Revit  (2022) to verify, and Does Not do it in older versions. This seems to be an "undocumented feature" in 2023. I knew you didn't get the Disconnect message in 2023, but hadn't noticed this yet. It also seems to break the Demo'd pipe in the Existing view where the Tee was placed in New Construction.

I'd say make sure you have the latest patch installed, but there don't appear to be any for 2023 yet. 

[RobDraw]

This "issue" is new to 2023, as @hmunsell has noted, since the behavior of demolished objects has changed so they keep pre-demo system information.

Have you tried turning off the demolished piping before drawing the new pipe? Does the demo automatically connect to the new when it is turned back on?

[jhendrickerBGPNW]

Yes, the issue occurs regardless of whether or not the demolished piping is visible while modeling the new. Hiding through phasing, filter, or otherwise doesn't seem to address the issue. Not sure why this behavior is happening even when the demolition occurs in an earlier phase. My understanding of phases is that they are a "snapshot", so it confuses me that it will modify elements from not only the current phase.

[RobDraw]

Wow, that is messed up. I don't usually blame the software but that is something that Autodesk should have sorted out. I'm surprised it hasn't come up here, in this forum, before now.

Does this happen only when it's the same system or does it do it regardless of system?

[jhendrickerBGPNW]

I'm also surprised. I didn't see any other posts, other than a small mention of the issue (which got no response) in a separate post regarding a different issue with demo pipes in R23.

Good idea to check different systems. No, I just checked and it only happens when it is the same system. I also checked and it also occurs with ductwork, which I expected.

[RobDraw]

It sounds like you need separate "demo" systems.

[jhendrickerBGPNW]

I created a test "demo" system, and it did fix the issue. An important thing to note is that you must divide the system after demolishing and BEFORE changing the demolished pipe to the "demo" system, otherwise it will change the existing to remain pipe to the "demo" system as well.

I wish there was a better workaround than this, but thank you for your help. Hopefully Autodesk can fix this issue in the future.

[RobDraw]

Autodesk "fixed" the demolition tool by popular demand. People wanted the pipe to hold onto the system information. Be careful of what you wish for, people!

Not sure if undoing this "fix" will be a high priority. It actually makes a lot of sense to have "demo" systems for a number of reasons. The least of which is not, to not interfere with existing to remain systems. A third party solution might come around faster than Autodesk.

[iainsavage]

This post might be relevant.

https://forums.autodesk.com/t5/revit-mep-forum/revit-2023-demolition-problem/m-p/11217338

It used to be (and in my opinion should be) that demolished items are disconnected and effectively "dead" (as they would be in the real world). In 2023 it seems that is no longer the case because people wanted demolished items to retain system and flow information etc.

[hmunsell]

I knew they allegedly "fixed" it so the demo didn't break the system, but I hadn't had a chance to play with it yet.  My Engineers are not going to like this "Fix".... 

[RobDraw]

When the time comes, you will have the new workflow ready for deployment.

[NateBrush]

We are now running into this issue on a complicated remodel. This really seems like something that either wasn't tested before R23 was deployed or Autodesk didn't do a good job of prompting us to revised workflows. Either way, it looks like we're going to have to figure out a new workflow mid-project.

[ToanDN]

Put them in different Design Options.

[Taylor-PDG]

I like the change to preserve system info in demolished pipe, but I wish it were a little more fleshed out. I've got a couple different workarounds (demo systems and just changing the elevation of the demolished pipe by a couple inches) but I wish the "connect automatically" toggle in the Place Pipe menu had the option to assign conditions. I'm sure that would open up a whole new can of worms though, and at the end of the day it's at least an improvement over previous versions in my opinion. 

[DZimmerKVJT2]

I see you guys mention that this is a problem new to 2023. This occurs in 2022. I was also told that it's related to the demo phasing problems. For all releases up to 2024, we use demo overide for something we seek to demo. 

It's a fairly easy issue for me to avoid, since our models are really only 2d - i can move things up or down and it won't matter.

But the good news is (i'm told) that this isn't an issue for 2024. 

I've even connected water lines to entirely different systems that weren't part of plumbing. But in that instance, it was not a demo'd object.