@HVAC-Novice wrote:
I'm not saying modeling and scheduling pipes is bad. But detailing every fitting is overly complex IMHO. YMMV. I never said that I do this. We’re talking about some transitions, not hours of complex modelling.
I also simplify straight pipes and in my model they just look like one long pipe. In practice, it may be multiple 8'sections with fittings.
In the UK this would be acceptable and is what I already do because standard couplings in running lengths of pipe do not need to be enumerated.
I don't model and schedule all the fittings.
In the UK this would not be acceptable because in bills of quantities we are required under standard measurement rules to describe and enumerate every fitting. I did not however say that I model every fitting but what we’re talking about here are some transitions which Revit inserts automatically and then counts for me so why would I not do that?
Obviously someone may benefit from modeling all fittings.
I also change the level of detail depending on if this is done by a contractor (and they have to figure out number of parts), or if that is a project I have to order all material for. I don’t order anything but I have to describe everything in enough accuracy that competing tendering Contractors are all pricing on an equal basis with as little as possible left to chance or interpretation.
Typically the installer will just order special fittings based on what they see or worked out from the submittals.
At tender stage they’ll price those unspecified fittings as £1 and then later say that the actual fitting is £100 and wasn’t sufficiently described in tender documents so they have a valid claim for more money. I’ve been doing this for nearly 40 years, I know what I'm talking about, for UK at least.
This isn't something that needs to be in the model. Chances are, due to some manufacturing change, or using of a different manufacturer or model, they need to use something else anyway. And the installer will change routing somewhat anyway. Again, I need to describe and enumerate items for tender purposes and using the model to help with that is easy. Maybe bends shouldn’t be in the model either? Or tees? Or pipes? We could just have dumb lines - in which case I could use Autocad, maybe even the LT version?
As for the nominal sizes: the actual pipe size (ID) is important for hydronic calculations. Obviously, I’m not stupid. Again, been doing it for nearly 40 years and I went to University before that.
So that should match what is nominal in your country. Incorrect. Maybe for Imperial but not for metric systems. Traditionally steel and iron nominal sizes are based on pipe bore, copper and plastic on outside diameter, but the inside diameter is obviously still the one used for velocity and friction calculation (friction varies with d^5, right?). E.g. 4” is nominally 100mm steel, 108mm copper, 125mm plastic pressure pipe, 110mm plastic soil pipe etc. Revit pipe segments include the ID, OD and ND for that very reason.
Otherwise the velocities are wrong, and with that presssure drop. As above.
For refrigerant, that calculation isn't done in Revit. So you only really need a separate pipe type for scheduling purposes. I totally agree and never said otherwise. I specifically made no comment about the fluid type.
