Going to start on this one soon.

[hvacvegas]

AS I understand it... Street fittings, along with reducing bushings... are a no-no according to natl gas code. Not sure why... however they are.

Anyone know the details of this code?

I've been told, but not shown in the books this:

All things have a rating in our industry. All things are tested.
Although BI fittings exist, does not mean that they passed the strength test for all things that use BI.

BI used in boiler piping has a different strength test requirement than gas.

Bushings/street fittings have passed the strength tests for boiler piping, but failed to meet the requirement for gas piping.

Now, if you look at a manufacturers instructions on certain brand furnaces, they will recommend using a street 90 on their gas valves.
Goodman left gas entry is one example.

Now, one would say "hey, they can't do that! ASME says they can't!"

Except that manufacturers recommendations can trump it, primarily because they are responsible if it fails.

It's not exactly that street fittings and bushings are "banned", it's that their "not approved".


This is kinda related to PVC flues. No authority has technically "approved" PVC pipe for furnaces, yet it's been done for years.
The PVC manufacturer has approved their pipe for these installations, and thus can be used.

[Frederick_Tech]

I was under the impression that you cannot use a gas hot water heater with a desuperheater? Maybe I am ms-led?

Work looks amazing (with the exception of the source piping) but Kevin is correct. You are not supposed to hook a hot water generator to a gas water heater.