Product(s):	OpenBuildings Designer
	Version(s):	CONNECT Edition
	Area:	Plumbing Design
	Subarea:	Routing

Problem

I have a fire protection system that is rotated at a non-orthognal angle and I need to route a 1" pipe from the bottom of a 1/2" sprinkler head to a 3" main pipe. 

However, I cannot find a good way to accomplish this. First, when placing a 1" pipe there is no transition generated between the 1/2" end of the sprinkler head and the 1" pipe I am placing, even with Size disabled in the ribbon bar.

I also cannot seem to route a pipe from that general sprinkler head location straight across to the main pipe because the entire system is rotated. When I do this the new 1" pipe it is not perpendicular to the main pipe so the Tee is at an angle:

Solution

For increasing the pipe size extending down from the sprinkler head, you will need to first place a 1/2" extension pipe from the bottom of the sprinkler head. This is because transitions were designed only to connect directly to pipe and not to pipe fittings or equipment.

However, even with a vertical pipe extension, the aspects that make this situation more difficult than normal are:

1. The entire system is designed at an angle, so the sprinkler head needs to connect to the main pipe at that non-orthogonal angle when viewed from a top orientation.
2. The pipe connecting the sprinkler head to the main pipe not only needs that non-orthogonal angle, but it also needs to slope downward since the main pipe is at a slightly lower elevation than the sprinkler head + extension.
3. By default, when connecting pipe to pipe that connection will always be made at either an end or midpoint. In this case the midpoint of the main pipe is not at the desired XY location in relation to the sprinkler head, which is why the angle of the new 1" pipe is not perpendicular to the 3" main pipe.

In order to accomplish both the correct slope and desired XY angle you can follow these steps:

- Place a construction line from the bottom of the sprinkler head's extension pipe to the midpoint of the 3" main pipe. This is the angle that OpenBuildings Designer will place the connecting pipe by default, but more important, that connection will be at the correct elevation to accommodate the required slope.

- Calculate the angle required to connect the sprinkler to the 3" main pipe while remaining perpendicular to it, and create a rotated copy of that first construction line.

- Next, place the new 1" pipe starting from the 1/2" extension pipe located at the bottom of the sprinkler head, and ending at the endpoint of that second construction line. This will automatically place a 1/2" to 1" transition at the 1/2" pipe extension and a Tee at the 3" main pipe.

  

- Finally, change the value of the resulting Tee's "Center to Branch Distance" value to a more appropriate value if needed.