NFPA 30 rules for fuel oil piping 1

[alehman]

I am working on a design standard for my client for fuel oil piping (for diesel generators). This pertains to light fuel oil (#1 or #2 diesel). NFPA 30 states that piping shall comply with ASME B31 and that low melting point allows (such as bronze, aluminum, nickel, etc) may be used underground or where they do pose "undue risk".

I called NFPA and they said that the interpretation of "undue risk" is up the local authority, but that if a fire were to occur and the fuel line ruptured inside a building, that would be a significant risk.

We see brass and bronze components used commonly in fuel oil piping, but a strict interpretation of NFPA 30 would seem to require steel. The IFC refers to NFPA 30 for fuel oil piping requirements.

Has anyone had experience with local inspectors not permitting low melting point allows in fuel piping?

Thanks,
Alan

 

[stookeyfpe]

See NFPA 37 because you are dealing with fuel oil for a generator. NFPA 30 applies to the tanks - everything else is NFPA 37. I seem to recall NFPA 37 references ASME/ANSI B31.9.

 

[alehman]

NFPA 37 (2006) says, "Fuel piping shall be in accordance with Chapter 5 of NFPA 30." *

The * refers to an appendix which states that piping systems "...should be designed to minimize piping failure" and goes on to give examples of welded pipe joints and use of flexible connections at the engine. The appendix however is not part of the actual code. Also, relatively few authorities have adopted NFPA 37, but most enforce 30.

I think the 2003 edition made reference to steel piping for connection to the engine. As a side note, the state of Michigan Department of Environmental Quality enforces NFPA 37 (2003) and has required retrofit of my client's generators rubber fuel lines.

 

[DavidCR]

Some codes does not allow the use of brass and similars in relation with the presence of sulphur that may be present on fuel oils. This issue has lots of discussion, so there is not a clear technical answer on when to use brass components for fuel lines for all the cases.

The B31.1 code is related to "Power piping" and is much stringent in some aspects than the B31.3 "Industrial Piping" code.

 

[alehman]

Thanks David. Any ideas where I might find more info on the sulfur concern?

 

[kenvlach]

alehman, sulfur in fuel attacks zinc. This is the reason that galvanized and brass (copper-zinc alloy) are banned for diesel & similar oil fuel lines and tanks. Also, copper can tarnish/corrode; see ASTM D130, 'Standard Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test.'

http://www.astm.org/cgi-bin/SoftCar..._PAGES/D130.htm?L+mystore+xqqp3792+1186560954

Please also see the earlier thread
Piping & fluid mechanics engineering Forum
thread378-178948

 

[alehman]

Kevin,
Thanks for the info. But, by whom is brass banned?

The links indicate some possible concerns with corrosion, but I didn't see any outright prohibition on brass.

thanks,
Alan

 

[MJCronin]

Am I missing something here..???

Why not simply use Schedule 40, A53 "black iron" pipe /

It will be cheaper than any copper bearing material and the discussion is ended.

I have seen many industrial fuel-oil systems.....and they all use carbon steel pipe....which is in conformance with NFPA-30


-MJC

 

[alehman]

My concern is primarily related to valves, strainers, etc. The pipe is always black steel.

Y-pattern strainers, swing check and solenoid valves are most readily available in brass and that is what we get unless we force the issue. Several suppliers are complaining about my insistence on steel for these components and questioning the reason.

 

[MJCronin]

Go with cast iron piping components and be done with it.

For small items like solenoid valves, go with stainless steel. If they dont like it, state that NFPA banns such materials.

If challenged, state that, since it is impossible to determine where a particular componet will be installed in a system (ie. where it may or may not pose "undue risk") none of the components can be constructed from the restricted materials.

My opinion only

-MJC

 

[westend392]

Any thought on suggested coating system for the black iron pipes especially for outdoor application (such by the main tank)?

 

[MJCronin]

westend....

I believe that a close read of NFPA-30 by the local authority may require double containment piping system for the fuel oil piping.

If it does, I would suggest plastic external pipe and "black iron" carbon steel piping internally. No valves should be located in the buried portion of the system.

If a double containment system is not required, then the old "fiberglass wrap on coal tar epoxy coating" method should be considered. There are firms that specialize in this and can holiday test the installation at completion.

My opinion only

-MJC

 

[alehman]

NFPA 30 does not require containment, as interpreted by must authorities. For exposed applications, I usually try to get factory coated if possible.