5-Year Obstruction Inspection

What are the procedure and proper documentation for the NFPA 25 5-Year Obstruction Inspection?  Does it need to be done?

The requirement to perform a 5-year obstruction investigation is now required in NFPA 25 2008 Edition Section 14.2.1.  The language states: "An inspection of piping and branch line conditions shall be conducted every 5 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 inspecting for the presence of foreign organic and inorganic matter." If your local AHJ enforces the 2008 Edition, you will now be required to perform the test. 

Be sure you do an assessment first to see if you have any of the conditions listed in 10-2.1.  An example Obstruction Investigation procedure is listed in the Appendix (not a code requirement).  If your water source is a municipal water supply, feel free to educate your AHJ if your system doesn't exhibit any of the conditions listed in NFPA 25: 10-2.1 and your quarterly sprinkler flow testing, annual main drain testing, annual fire pump flow test and 5-year standpipe flow tests are appropriate and consistent. 

NFPA 25: Inspection, Testing and Maintenance of Water-Based Fire Protection Systems, 1998

Chapter 10 Obstruction Investigation 
10-2* Obstruction Investigation and Prevention 
10-2.1* 
To ensure that piping remains clear of all obstructive foreign matter, an obstruction investigation shall be conducted for system or yard main piping wherever any of the following conditions exist:
(a)     Defective intake for fire pumps taking suction from open bodies of water 
(b)     The discharge of obstructive material during routine water tests 
(c)     Foreign materials in fire pumps, in dry pipe valves, or in check valves 
(d)     Foreign material in water during drain tests or plugging of inspector's test connection(s)
(e)     Plugged sprinklers 
(f)      Plugged piping in sprinkler systems dismantled during building alterations 
(g)     Failure to flush yard piping or surrounding public mains following new installations or repairs 
(h)     A record of broken public mains in the vicinity 
(i)      Abnormally frequent false tripping of a dry pipe valve(s) 
(j)      A system that is returned to service after an extended shutdown (greater than 1 year) 
(k)     There is reason to believe that the sprinkler system contains sodium silicate or highly corrosive fluxes in copper systems 
(l)      A system has been supplied with raw water via the fire department connection. 

10-2.2* Obstruction Prevention. 
Systems shall be examined internally for obstructions where conditions exist that could cause obstructed piping. If the condition has not been corrected or the condition is one that could result in obstruction of piping despite any previous flushing procedures that have been performed, the system shall be examined internally for obstructions every 5 years. This investigation shall be accomplished by examining the interior of a dry valve or preaction valve and by removing two cross main flushing connections. 

10-2.3* Flushing Procedure 
If an obstruction investigation carried out in accordance with 10-2.1 indicates the presence of sufficient material to obstruct sprinklers, a complete flushing program shall be conducted. The work shall be done by qualified personnel.