Paul Su and David B. Fuller 
FM Global 


Quote:
Orient longitudinal pipe weld seam toward building roof  to prevent weld having deposits on it that will corrode?
Protect pipe from all contamination prior to installation.??
Fill dry pipe or preaction systems with nitrogen as supervisory gas (e.g., use on-site nitrogen generator) to mitigate galvanized steel pipe corrosion in the dry type FPS?
Install an FM Approved air-venting device to remove trapped air in wet pipe systems to mitigate pipe corrosion near air pockets. ?
Use treated water such as municipal water (i.e., avoid untreated raw water) ?
Minimise the frequency of draining and refilling.??
Avoid trapped air in within sprinkler systems??
Avoid the use of rolled or grooved fittings in dry & preaction systems.??
Use internally-galvanised pipe for dry preaction systems??
Dry & preaction piping should be pitched toward low-point drains??
use Nitrogen gas in preasction sprinkler systems as a supervisory gas??
It is not recommended to use pipe-cleaning and water treatment chemicals for sprink systems
endQuote