Flexible conduits

[grahamlyon1977]

Here in Australia we are modelling more and more 'sweeping bends' conduits, mainly due to the new NBN (National Broadband Network)

Revit does not allow us to draw a conduit with a radius in one go, we have to attach bends etc, this does not work in this scenario, we need to have one element but this is not possible without drawing an 'in place' family each time, which is totally unviable due to time constraints/changes.

Surely it would not be too hard to draw a conduit from point 'A' to point 'B' as you would a spline in CAD?

[Martin__Schmid]

Thanks for the suggestion.

Can you elaborate what actually is meant by a flexible conduit?  E.g., a reference to a manufacturer's product, link to PDF, or other relevant catalog information.

[grahamlyon1977]

Please refer to my original post, it is all the same conduit as we always use, mainly 23mm OD in the NBN installations, but instead of a rigid configuration of the conduits using bends, elbows etc, it basically goes from A to B as the crow flies but with a 'flexible' path, the installers here actually call them 'sweeping bends' as the conduits will NEVER be installed in a straight line.

My problem in revit is that when I want draw a conduit from point A to point B, if using the path that the conduits will be installed to, revit will produce loads of minor bends, which then screws up my scheduling, therefore the only way to draw it properly, is to do an in place family, but on tower block installations etc, this will be hundreds of conduits, which makes it impossible to do, therefore we have to cheat to get the end product as revit makes un-feasible to do!

[Anonymous]

Martin we specify Anaconda Metallic Flex conduits for use in Electrical pits from conduits to Cable trays here is the link to give you an idea

http://www.anamet.nl/products/anaconda-flexible-conduits-and-fittings/

They work very similar to the flex pipework for sprinklers so i would assume you could use the same technique where you connect to the end of the conduit and run from there they would just require different fitting types.

[Sean.Lawrence]

Martin,

If I think the addition of a Flexible Conduit function is becoming more critical for Revit. In Australia we use a lot of what is called flexible conduit, in transport and commercial street lighting and services.

Link to flexible corrugated PVC http://www.clipsal.com/Trade/Products/Catalogue?c=1&ms=5&s=14&mg=385

I think having a Flexible Conduit function essentially the same as the Flexible Duct or Pipe in Revit, except with conduit connectors is essential to proper electrical modelling.

I have not seen any mention of this in 2018. Is this something in the works?

Regards 

Sean

[engissamadnan]

I'm relay surprised that Autodesk has missed this type of conduits .... Its widely used in electrical installation .. I wish to see it in the next releases of Revit .

[Kevin_Laskowski]

I forwarded this on to every Electrical modeler I know. Hopefully this catches on and gets more traction. Good luck 🙂

[dominikleuchter]

@grahamlyon1977

I totally agree with you. This is a must-have for electrical installation.

@martin.schmid

You could probably use Flex Duct from HVAC as a template for the flex conduits.

That´s pretty much how they should work.

[Martin__Schmid]

I think what is being described here may be two separate things... 

1. flexible corrugated PVC - which may be similar in concept to Flex Duct/Flex Pipe in Revit.  Have you used flex duct / pipe to model conduit presently?  Does it provide you with the control and capability that you need from a geometry perspective, or does it leave anything to be desired?  The reason I ask is that we've had requests for folks that have attempted to route PEX piping, and have struggled, as the functionality was designed for flexible connections at equipment more so than routing long distances, and on multiple planes. 

2.  in the original post indicated "all the same conduit as we always use" and "allow us to draw a conduit with a radius".   what I interpret that to mean, and along with the provided image, is that he is looking to have rigid conduit that allows bending to conform to a large diameter radius. 

[grahamlyon1977]

@Martin__Schmid

What I was originally asking for which may be a little lost in my initial explanation was the functionality in Revit MEP to model an electrical conduit the way you would model a flex duct in mechanical services.

I need to model a conduit at the normal diameters (23mm, 50mm, 100mm OD) from Point 'A' to Point 'B' like we would draw a spline in AutoCAD. it needs to snake around corners etc and be on the system category of electrical conduits.

Why would we model it as duct/pipe? it's an electrical fixture.

This is a major problem in Revit MEP to just have the function to model 'rigid' conduit, the practical application for this is not like this anymore.

My initial post has a screenshot of a drawing from AutoCAD, if we could replicate this function Revit MEP and have as a 3D element, this would make mine and many others lives easier!

[Martin__Schmid]

@grahamlyon1977 - thanks for the clarification.

to address your question, "Why would we model it as duct/pipe? ":

This was was really more directed toward @dominikleuchter 's suggestion that "could probably use Flex Duct from HVAC as a template for the flex conduits"...

My inquiry in the prior thread seeing if this was truly the case... as I stated:

Does it provide you with the control and capability that you need from a geometry perspective, or does it leave anything to be desired?  The reason I ask is that we've had requests for folks that have attempted to route PEX piping (like this and this), using flex piping, which is basically the same editor as Flex Duct... and they have struggled, as the functionality was designed for flexible connections at equipment more so than routing long distances, and on multiple planes. 

[dominikleuchter]

Sorry for creating confusion here. I may have expressed myself wrongly.

Basically i meant it as g.lyon wrote it. A flexible conduit as additional family and not a Flex Duct/Pipe replica or something.

What I actually wanted to say was that it should have the flexibility of Flex Duct / Pipe.

I have not used Flex Duct / Pipe in detail yet but I got the idea from trying out several standard Revit Familys to see if there is one with similar to the flex conduit we need.

Sorry everybody.

@Martin__Schmid@ wrote

Does it provide you with the control and capability that you need from a geometry perspective, or does it leave anything to be desired?  The reason I ask is that we've had requests for folks that have attempted to route PEX piping (like this and this), using flex piping, which is basically the same editor as Flex Duct... and they have struggled, as the functionality was designed for flexible connections at equipment more so than routing long distances, and on multiple planes.

Might try it out and see if this is the case.

[dominikleuchter]

@Martin__Schmid@ wrote

Does it provide you with the control and capability that you need from a geometry perspective, or does it leave anything to be desired?  The reason I ask is that we've had requests for folks that have attempted to route PEX piping (like this and this), using flex piping, which is basically the same editor as Flex Duct... and they have struggled, as the functionality was designed for flexible connections at equipment more so than routing long distances, and on multiple planes.

[dominikleuchter]

Does it provide you with the control and capability that you need from a geometry perspective, or does it leave anything to be desired?  The reason I ask is that we've had requests for folks that have attempted to route PEX piping (like this and this), using flex piping, which is basically the same editor as Flex Duct... and they have struggled, as the functionality was designed for flexible connections at equipment more so than routing long distances, and on multiple planes.

[Martin__Schmid]

Thx for clarifying @dominikleuchter - my question still stands... I'd still be curious about the ability to model w/ flex pipe/duct... if you had the exact same geometric functionality to model flex conduit... what works well about it?  what doesn't work well?  If you have chance to give it a try, it would be interesting to get that feedback.

[Kevin_Laskowski]

Martin
It leaves Six things undesirable:
-Past job we uploaded our Revit model to the General Contractor for clash detection. Forcing us to use "flex duct" as an electrical device sometimes plays havoc on the coordinators clash files because they will inadvertently use system filters to separate and export Trade designated coordination models into Navis for clash detection. Since Flex duct is not an electrical system, it ended up in the Mechanical contractors NAVIS clash file. This was a Lesson learned. The solution was to use a "work around".
-Primary and secondary panels with a transformer in-between them we have to use a conduit elbow for GTP then filter out off for coordination upload, we use the flex duct as the flex connection because in actually can fit more like the field install. If this was an electrical system GTP would probably update their program to "connect" these on the autonomous one-line.
-Creating a BOM for Flex/Liquid Tight we have to add an extra step to the schedule so its description is correct.
-Have to customize fittings with conduit and flex duct connectors on each end.
-For BOM reasons-cannot get an accurate Run length to calculate wire lengths. The flex or liquid tight does not get captured in the total length of the run. We have to manually add length, (this is AKA a "workaround").
-GTP does not automatically recognize Flex Duct at final equipment connection, have to use a manual "work around" (use conduit that will be filtered off on Coordination model export) as opposed to the program autonomously adding the P.O.C. intelligence.

The electrical "Flex" family needs all the descriptions from the NEC (National Electrical Code-North American).
Here are a few examples:
-Flexible metallic Conduit (MC) i.e. aluminum or steel
-Liquid tight Flexible Metallic Conduit (LFMC) i.e. Steel, Aluminum
-Liquid tight Flexible Nonmetallic Conduit (LNFC) i.e. PVC

The Cable and Wire Family needs all the descriptions from the NEC (National Electrical Code-North American).
Cable and wire would have absolutely created value for my department on our last job for BOM purposes. Using conduit as cables in tray was very cumbersome, modifying conduit would inadvertently delete or move sections of tray furthermore the bending radius of wire is smaller than what Revit would allow for the conduit.

-Cable i.e. Triplex, TC or other types, Sometimes cabling can have a 3.5" O.D on these.
-Wire i.e. THHN 500 mcm Cu.
Please try to push this product improvement especially when this has been posted for over 3 years.

[Martin__Schmid]

 Hi @Kevin_Laskowski - thanks for those details, very helpful to understand the scope of the problem... I am still curious, from a geometric perspective, if the way that the flex duct/pipe geometry itself behaves, have you run into any particular challenges when using it to geometrically represent flex conduit... or if it works perfectly well... e.g., if the same geometry/modelling interactions were applied to a flex conduit element, would you be happy, or would you say, "when I'm trying to do certain things to get the flex to route a certain way, or be at a certain elevation, or go through a particular point it doesn't do what I want."

[Kevin_Laskowski]

Martin

It works extremely well . Possible attribute to add would be minimum allowable bending radius based on type and diameter.

 An example for Armored Cable (AC) would be NEC 320.24 Bending Radius.  The radius of the curve of the inner edge of any bend shall not be less than five times the diameter of the Type AC cable.

 An example for metallic Clad Cable Cable (MC) . The radius of the curve of the inner edge of any bend shall not be less than required in 330.24(A) through (C).
(A) Smooth Sheath.
 (1) Ten times the external diameter of the metallic sheath for
cable not more than 19 mm (3⁄4 in.) in external diameter
 (2) Twelve times the external diameter of the metallic sheath
for cable more than 19 mm (3⁄4 in.) but not more than
38 mm (11⁄2 in.) in external diameter
 (3) Fifteen times the external diameter of the metallic sheath
for cable more than 38 mm (11⁄2 in.) in external diameter

[dominikleuchter]

Hi @martin.schmid

I did some testing with the Flex pipes to answer your question about the "geometric perspective" you asked for.

@Martin__Schmid  wrote
... I am still curious, from a geometric perspective, if the way that the flex duct/pipe geometry itself behaves, ...

Here my opinion on what works well with Flex Pipe and what doesn´t:

- Basically the way Flex Pipe can be placed / drawn works as we need it. Especially, the possibility to adjust it afterwards (through "vertex" and "tangent" points). That's the kind of flexibility a flex conduit should have.

- What is missing is the possibility to place it in a section view.

- Visually, the Flex conduit should basicly look like a standart conduit and on "Coarse" detail level simply like a line (maybe dashed, that's at least our standart)

- As Kevin wrote, minimal bending radius, adjustable in the electrical settings - conduit - size (just like for the already existing rigid conduits) would be nice too.

- The "Paralell conduits" function should also be working with the flex conduits, if possible.

- Also good would be the ability to connect the flex conduits to rigid conduits (like Flex Pipe / Draw Pipe)

 

As an alternative to a completely new flex conduit family with flex pipe as a template, you could add a bend fitting to the existing conduits that can be draw and adjusted like a spline. (if that's easier / faster for you to add)

Or you could add the "Draw" option to conduits, which is known from beams. (They can be placed as Splines.)

@grahamlyon1977  and @Kevin_Laskowski feel free to correct/complete me.

[grahamlyon1977]

Hi @dominikleuchter

What you have summed up (expertly by the way!) is exactly what I was after when I originally posted this!

Maybe if we get this incorporated, we may move onto the other deficiencies Revit MEP has on us poor miserable souls that do Electrical 🙂 

My main ones to tackle next are 

1) busbars

2) electrical wiring

and THE MAIN ONE THAT DRIVES ME INSANE - RAKED CEILINGS!!

I have posted all of these on this ideas page, maybe we get gain some support?

Thanks

[fabian.brunner]

With the conduit we use today, it´s not possible to design true BIM Projects (Plan as built). With three significant improvements, we could avoid most of our Problems we have today.

1. Flexible Conduit

In concrete buildings most of the conduits are flexible. To draw realistic Models, electrical engineers need a flexible conduit, like the flex pipe.

Picture of flexible conduits in a concrete ceiling

2. Systems for Conduit

Conduit can contain different Type of media, for example a data-cable or a lighting-connection. To specify what’s the conduit used for, we need the possibility to classify them into Systems.

Sample of an electrical plan with different Systems in different colors

3. Wire in Conduit

Conduits contain different wires (single or multiple). For true calculations there must be a possibility to add wires in our conduits.  

[dominikleuchter]

There is already a similar/related idea:

https://forums.autodesk.com/t5/revit-ideas/flexible-conduits/idi-p/6343138

[MicG]

 For 3 there's some more details existing in https://forums.autodesk.com/t5/revit-ideas/introduce-cables-not-just-wires/idi-p/7970133