Inventor Tube & Pipe - Remove Minimum Segment Rule

[l.stubbsPS49C]

Tube and pipe requires a minimum pipe length between two fittings (bends, tees valves etc). Our systems have compact manifolds and more often than not there would be no straight lengths of pipe between fittings. I have set the minimum distance between fittings to 0.001mm to minimise the impact of this, however there is no method of cutting back two fittings to make them tighter together. See below an example of how some of our systems can look and how fittings are cut back when not using tube & pipe.

The minimum segment rule removes the creative freedom from the designer and becomes over-constraining, ultimately it should be the users decision to assess what can and cant be designed in the real world, not the computers. 

[Anonymous]

I didn't know this was an issue. Good find. Definitely should be resolved

[k.patelHRSB2]

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[james.bergey]

I have the same issue, however the issue for me is for butt weld connections.

I want to be able to weld an 90 elbow directly to another 90 elbow to create a 180 bend.

Or weld a tee directly to a weld neck flange or elbow.

This is further complicated by the weld gap being doubled when you create a .001" slice of pipe, and it fills the BOM with .001" pieces of pipe. I also worry about these "invisible" pieces of pipe messing with something as another CAD user may not know they are there. 

It will not allow me to enter a minimum segment length of zero. It gives me this error "The minimum Value should be greater than or equal to the incremental value", but there is no incremental value input in butt weld connections.

I can place these fittings manually and then autoroute off the other end of the fittings, but that really defeats much of the point of auto routing.

I suspect that auto route programming needs to have pipe constrained at each end of the route and then places the fittings in between and that is why it cannot have no piece of pipe even if it’s only .001”.

I looked on line for a solution to this, but any of the solutions I found were essentially work arounds, and/or what I already described.

[Payne_S]

This would be great. Maybe a "Minimize Segment" right click option.

[ppolcynBNVFN]

@james.bergey I'm having this problem now too. Any update?

[james.bergey]

Hi Guys, sorry I don't seem to get notifications on this thread despite having the "email me when someone replies" ticked.

Short answer, no, I have no further progress on this. The jobs I have been working on since have been Socket Weld, so this hasn't been an issue. Also I basically had a work around that I would just place the elbows etc. directly into the model and constrain them to the equipment and themselves to define my route, and then basically just use T&P to create the adaptable pipe lengths in between each fitting.  

We are changing how we are structuring our models now though so that we can better control the BOM/Parts list by each line number on our P&ID, and this means I can no longer construct routes this way, so this is rearing it's head again.

[james.bergey]

So update, I think I have a solution to this. 

I placed these two flanges in an assembly to represent a pump or tie point or something.

I then placed the next two flanges into the Run and used the Connect Fitting command to the previous two flanges.

Then I placed the elbows into the Run, and used the connect fitting command, and used the edit fitting orientation to aligned them as I liked.

Then I just used the autoroute to complete the path.

[ppolcynBNVFN]

@james.bergey yeah that seems to be the workaround, it just doesn't work so well when you need a tight turn in there that you would ideally connect elbow to elbow for

[Payne_S]

I would rather the 0.001 piece than have this. When you get to the parts list just give the 0.001 pieces a item number of XXXX and then they sort to the bottom. 

[james.bergey]

@ppolcynBNVFN You absolutely can do elbow to elbow direct connections, as I have done here.

Flnage, elbow, elbow all placed directly using the Connect Fittings command.

You can do as many connections as you like and then auto route from there.

You can even do direct connect fittings in the middle of the route and keep routing from there. 

@Payne_S You're welcome to do as you please, but I think that brings a host of other issues that lead to complications with the routing, instability/unpredictability of the route if you change location of equipment, or size of the line.  For example, if you want this connection I have just shown and you sketch your routes, you would need to route it so that you would have to calculate what the centre line radius of the elbow is, and then add .001" if you want to sketch it, or if you auto route it and then change the autoroute to a sketch then it would not stay adaptable if you were to change line size and then would end up with a longer piece of pipe in between the elbows. Also if you use the weld gap feature in your style it will double the weld gap. If you do use weld gap, you can add that manually when you Connect the elbow.

I always turn my autoroutes into sketches, and then play with which dims of the sketch are driver and driven so that the route will adapt to changes in the fashion I desire, and I define the route to faces such as pipe supports etc. so you would loose that adaptability for the direct connections if you change line size.

Also with this method you can actually use the minimum pipe segment as intended. On Buttweld connections you typically never want a straight section of pipe to be less than 1.5x the diameter of the pipe, or approx. min 2". You can't have welds that close to each other. So with this method, you can place the connections directly to each other, but you can set the minimum segment to 2" and it will hold that true for all other locations, which will be far more often than having to place the fitting directly. These were all of the issues I saw and specifically why I was looking for a solution.

My 2 cents, hope it helps. 

It's a pretty simple solution that if you don't know about it, you don't know about it... 

[james.bergey]

Oh, another thought about the advantage of placing them directly. If you have two different designers working on the same model at some point or as a Rev later this is a much easier method to pick apart what the previous guy has done. Can you imagine trying to find and understand what all the .001" pipe segments are through out the model. So we are trying to standardize the way we construct our routes between our designers, so we can more easily work on each others stuff.

[Payne_S]

I'm glad it works for you. I just simply do not prefer this method. When I need two fittings to butt up to each other, a simple measurement and +.001" gets it done. A 0.001mm would get it even more done. There are no issues with equipment moving / auto routes because I will not use a autoroute, my designs are far too complicated for auto route. I have found that having routes in between fittings like that actually causes issues when equipment moves, especially in self draining BPE tubing. Set your gap to 0.00 or 0.001 and show me a fab guy that can hold that tolerance. I specifically train my people to not do this method. I am glad this method works for you though.

SP

[Payne_S]

Out of curiosity, why would you need to pick apart 0.001 segments? Give them a item number of XXXX and they go to the bottom and be ignored. In a perfect world Inventor would allow fittings in a route to be connected without having to insert it in the route. The 0.001 segments are easily known to be basically a construction line that are ignored.

Glad it works for you though.

SP

[james.bergey]

I used to do all my routing a different way, and to be honest greatly prefer it, but we are adopting a standard here to ensure our BOM/parts list matches with the line number on the P&ID, and to do so there are significant limitations within Inventor that prevent me from doing my routing the way I prefer.

Also I am not the design, department, or engineering lead, I don't get to set the rules of how the company is run, so I am working to find the best modelling solution to meet the directive set out by the company. 

I used to place and constrain all my fittings to equipment and each other to create my routing at the assembly level and basically use T&P to create adaptable pipe lengths to complete the routes between the fittings, but this does not allow us to have the BOM structure as we like. 

[Payne_S]

If you have a line tag on a PD that matches a spool, why does a 0.001 segment interfere with that? We do not tag the spools on the PD so I do not have that variable to contend with. 

[james.bergey]

Short answer, I do not want the .001" segments, period. 

I want the elbows to be direct mounted and not part of the route sketch.

Also I really want the min pipe segment to be set to 1.5x pipe diameter to apply for all the rest of the pipe style.

[Payne_S]

Works for you, that's all that matters. Good day sir.