The Internal Inspection of Piping is required to be performed every 5 years to locate potential sources of materials that could cause pipe blockage. If any obstructing material is found, an Obstruction Investigation must be completed.
Internal Inspection of Piping
Among the changes in the 2011 edition of NFPA25 Inspection, Testing and Maintenance of Water Based Fire Protection Systems is the differentiation between the Internal Piping Inspection (formerly referred to as the Obstruction Inspection) and the Obstruction Investigation.
As per NFPA25 (2011 edition) 14.2.1, “An inspection of piping and branch line conditions shall be conducted every five years by opening a flushing connection at the end of one main and by removing a sprinkler toward the end of one branch line for the purpose of investigating for the presence of foreign organic and inorganic material.”
Note: If performing the inspection of a dry pipe or pre-action system, the sprinkler chosen for removal must be from the most remote branch line from the source of water.
The inspection is done to determine whether there are any foreign organic or inorganic material present in the piping. This includes silt, sand, rocks, wood, microbes, and even zebra mussels – basically, anything that will obstruct the sprinklers from working properly in the event of a fire.
If no foreign material is detected after the inspection is complete, then the system can be returned back to normal service. However, if those materials are present, a more thorough obstruction investigation must be performed.
The obstruction investigation is performed only when an obstructing material is found during the internal inspection. The internal examination takes places at:
- System Valve
- Cross main
- Branch line
If obstructing material is found, a complete flushing program will be conducted to remove the obstructions from the pipe or sprinklers.