Schedule 40 vs 10 for pre-action system

[Jeng84]

Need some help decoding and/or point in the right direction for steel pipe schedule for sprinkler systems per NFPA 13. I'm looking in NFPA 13 (2022 edition) and I can't find any section that talks about when/if Im allowed Schedule 10 piping?
These are the 2 questions I'm trying to find answers to in FNPA 13:
1) For a double interlock pre-action system (charged with Nitrogen) using black steel pipe - are Schedule 10 piping allowed or does it have to be Schedule 40? Or does it depend on the pipe size and/or pressure
2) For a regular wet pipe system (using black steel pipe) - is Schedule 10 pipe allowed? or does it depend on the pipe size and/or pressure

I assumed it would be Chapter 7 (Requirements for System Components and Hardware) section 7.3 for above ground pipe or Chapter 8 (Preaction system and Deluge systems) but I can't find anything specific.

 

[UFT12]

Both ASTM A795 and ASTM A53 are available in schedule 10 so there is not problem specifying it. However, there are restrictions. See 7.5.1.2.

There is nothing against using schedule 10 for dry pipe systems. However, given the requirements 7.5.1.2 there may be an other schedule more desirable (i.e. 40) in case you would like to have even butts at the connections which allows complete draining in the pipework. Otherwise, schedule 10 is fine.

 

[Jeng84]

thanks! very helpful! I also found Section 16.3.2 and 16.3.3, which I believe says the same thing you pointed out - If I want threaded fittings I have to use Schedule 30 (pipes 8" and larger) or Schedule 40 (smaller than 8")... But if Im not using threaded fittings I can use Schedule 10.
It doesn't seem like it's based on the type of sprinkler system (wet pipe vs pre-action) but just on the type of pipe and fittings