Pipe Accessory Vs Pipe Fitting

[Hugh_Compton]

I expect this is a drongo question but if I create a Gate Valve as a Pipe Fitting instead of a Pipe Accessory then when it is part of a pipe run I can select all the items and change the pipe run size in one move.  If the Gate Valve is a pipe accessory then it has to be resized separately from the rest of the run.

What is the problem with using a Gate Valve as a Pipe Fitting instead of a Pipe Accessory?  Am I defining my Pipe Accessories incorrectly?

[Bill.Knittle]

It's a matter of purpose or categorical classification. When you set your category to Pipe Accessory, you can dictate the element's Part Type. Accessories are usually your inline valves, sensors, etc.... of your Pipe network. When you set your category to Pipe Fitting, the Part Type configurations change to those dedicated for routing preferences like elbows, tees, etc....

The differentiator is the Lookup function is baked into Pipe and Conduit Fittings. Pipe Fittings automatically embed a Lookup Table Name system parameter into itself by means of the Pipe Fittings category. This allows the fitting to flex to the Pipe Size it connects to based on rules specified in the Lookup Table. That being said, you can create this behavior inside of a Pipe Accessory manually.

Create a Lookup Table Name parameter in a Pipe Accessory Valve family to make it behave much like a Pipe Fitting.

1. Name = Lookup Table Name
2. Discipline = Common
3. Type of Parameter = Text
4. Group parameter under = Other
5. Select the Type radio button.

Set your valve ID, OD, and Nominal parameters to refer to the Lookup Table you specify for your new parameter. Make sure that your Nominal parameters are set up with:

1. Discipline = Piping
2. Type of Parameter = Pipe Size
3. Select the Instance radio.

 Associate your Connectors to the correct Nominal parameters. You should be good to go.

[Hugh_Compton]

Hi Bill

Thanks for your reply.  On the attached I have made those changes but the Piping Accessory still isn't changing with the Pipe...??

[Bill.Knittle · Accepted solution]

I think the behavior is normal for both accessories and fittings. You need to change both after the fact. Neither resize when the pipe diameter is modified.

In the case of both, they will size properly according to the diameter of the pipe your adding them into. The valve will simply need to be editted from the Properties palette. For ease of use, have your valves Rad parameter perform the formula DN/2 rather than having the DN parameter perform the formula Rad*2. In the project, the DN parameter will be active for editing.

[Hugh_Compton]

OK, I get that. 

For now I have opted for the following approach with pipe accessories:

The Pipe Accessory description (used for tagging and schedules) & Pipe Size is in a Type Catalog.  Usual behavior here - when loading a Piping Accessory into a project Revit will ask for the size/s to be added.  In theory this will keep project sizes down.

As well as the simple Type Catalog I am using Lookup Tables.  The Pipe Size from the Type Catalog is used to find the other dimensions etc of the Pipe Accessory.  Multiple Type Catalogs can be usee without any problems (so far).  This means that for items such as flanges, threads etc a single Lookup Table will cover all Pipe Accessories meaning less typing in of dimensions overall. 

If anyone spots a problem with this workflow then please give me a nudge - I am very much a newbie and haven't produced a single drawing yet so pretty much 'guessing' my way through family creation. 

[Sandleaz]

You're not alone.  There are some people that expect that a valve will automatically resize itself (aka change it's type) if you resize the pipe.  REVIT does not do or understand this.  What most likely happened is when you resized the pipe, the valve remained and REVIT create reducer/increaser fittings at the connections to match the new pipe size.      

[Hugh_Compton]

Ah, close.  What happened was that I changed a Piping Accesssory type to a Pipe Fitting Type (it was a gate valve).  When I changed the size of the pipe run the gate valve changed it's size too. 

It does work but I might come accross problems further down the line so I'm trying to stick to the 'standard' way of using Revit for now.....