NFPA 25 Chapter 14

14.1 General.

This chapter shall provide the minimum requirements for conducting investigations of fire protection system piping for possible sources of materials that could cause pipe blockage or internal corrosion of system components.

14.2 Assessment of Internal Condition of Piping.

14.2.1

An assessment of the internal condition of piping shall be conducted on a frequency determined by 14.2.1.1 or 14.2.1.2 for the purpose of inspecting for the presence of foreign organic and inorganic material.

14.2.1.1

An assessment of the internal condition of piping shall be conducted at a minimum of every 5 years or in accordance with 14.2.1.2 for the purpose of inspecting for the presence of foreign organic and inorganic material.

14.2.1.2

Where an assessment frequency has been established by an approved risk analysis, the assessment shall be performed at a frequency determined by the approved risk analysis.

14.2.1.3

Tubercules or slime, if found, shall be tested for indications of microbiologically influenced corrosion (MIC).

14.2.1.4

If foreign organic or inorganic material that has the potential to obstruct pipe or sprinklers is found, an obstruction investigation shall be conducted as described in Section 14.3.

14.2.1.5

Nonmetallic pipe shall not be required to comply with Section 14.2.

14.2.2

In buildings having multiple wet pipe systems, every other system shall have an assessment of the internal condition of piping as described in 14.2.1.

14.2.2.1

During the next inspection frequency required by 14.2.1.1 or 14.2.1.2, the alternate systems not assessed during the previous assessment shall be assessed as described in 14.2.1.

14.2.2.2

If foreign organic and/or inorganic material is found in any system in a building, all systems shall be assessed.

14.3 Obstruction Investigation and Prevention.

14.3.1

An obstruction investigation shall be conducted for system or yard main piping wherever any of the following conditions exist:

1.      Defective intake for fire pumps taking suction from open bodies of water

2.      Discharge of obstructive material during routine water tests

3.      Foreign materials in fire pumps, dry pipe valves, or check valves

4.      Foreign material in water during drain tests or plugging of inspector’s test connection(s)

5.      Unknown materials heard in the system piping during draining, refilling, or otherwise flowing water through the system

6.      Plugged sprinklers

7.      Foreign organic or inorganic material with the potential to obstruct pipe or sprinklers found in the pipe

8.      Failure to flush yard piping or surrounding public mains following new installations or repairs

9.      Record of broken public mains in the vicinity

10.  Abnormally frequent false tripping of a dry pipe valve(s)

11. System returned to service after an extended shutdown (i.e., greater than 1 year)

12. Reason to believe that the sprinkler system contains sodium silicate or highly corrosive fluxes in copper systems

13. System supplied with raw water via the fire department connection

14. Leakage caused by internal corrosion

15. A 25% increase or a 5-second increase for portions of systems protecting dwelling units in the total water delivery time for dry pipe systems and double interlock preaction systems, with normal air pressure on the system and starting at the time of fully opened inspection test connection, when compared to the original system acceptance test

16. Failure to maintain a nitrogen supply, except in instances of preplanned impairments, installed in accordance with NFPA 13 when a Hazen-Williams C value of 120 is used for dry and preaction systems.

14.3.2

Systems shall be examined for internal obstructions where conditions exist that could cause obstructed piping.

14.3.2.1

If the condition has not been corrected or the condition is one that could result in obstruction of the piping despite any previous flushing procedures that have been performed, the system shall be examined for internal obstructions every 5 years.

14.3.2.2

Internal examination shall be performed at the following minimum five points:

1.      System valve or water control valve, where provided

2.      Cross main – most remote end of remote cross main

3.      Branch line near the most remote line at connection to cross main

4.      Branch line near the most remote line at end of branch line

5.      Branch line piping directly connected to the most remote low point drain

14.3.2.3

Alternative nondestructive examination methods shall be permitted.

14.3.3

If an obstruction investigation indicates the presence of sufficient material to obstruct pipe or sprinklers, a complete flushing program shall be conducted by qualified personnel.

14.3.4

Tubercules or slime, if found during an obstruction investigation, shall be tested for indications of microbiologically influenced corrosion (MIC).

14.4 Ice Obstruction.

Dry pipe or preaction sprinkler system piping that protects or passes through refrigerated spaces maintained at temperatures below 32°F (0°C) shall be inspected internally on an annual basis for ice obstructions at the point where the piping enters the refrigerated area.

14.4.1

Alternative nondestructive examinations shall be permitted.

14.4.2

All penetrations into the refrigerated spaces shall be inspected and, if an ice obstruction is found, additional pipe shall be examined to ensure that no additional ice obstructions or ice blockages exist.