Access Panels Spacing

[Przrat]

Can anyone tell me the specific NFPA Code that indicates how far apart the access doors should be? It look to me that if refers to duct that someone can crawl into not narrow duct that doesnt allow full body entry.

 

[Grant]

NFPA 96 2008ed.
7.4.1.2 "Where an opening of this size is not possible, openings large enough to permit thorough cleaning shall be provided at 3.7m (12 ft) intervals".

The "size not possible" refrences 7.4.1.1 20 x 20inch openings for personnel entry

 

[Przrat]

Thanks

ed