Per NFPA 25, SoniTech NDT's ULGW scanning service satisfies the Internal Piping Condition and Obstruction Investigationthat is now required at a minimum of every 5 years per section 22.214.171.124 or when any of the conditions occur under section 14.3.1.
The NFPA ranks improper maintenance as the second most common reason for
sprinkler system failure, directly behind manually shutting down the
system before a fire. Furthermore, the National Fire Sprinkler
Association lists corrosion and freezing as two of the major causes
behind sprinkler system failure.
Considering the magnitude of
responsibility associated with these systems, implementing a Predictive
Maintenance program for your fire sprinkler system and addressing issues
BEFORE they arise are critical to keep these important systems operating
Modern Fire Sprinkler Systems are primarily comprised of two designs,
dry and wet systems, each with its own corrosion issues. SoniTech's patented ULGW guided wrap wave scan technology can detect these
issues in either system type, as described below.
You may be
thinking that if you don't see a problem, your system is okay. This may
not be further from the truth because corrosion is often undetectable by
external visual inspection. While the dangers of a dripping/bursting
pipe are fairly obvious, with water damaging sensitive equipment or
data, the internal corrosion can be much more devastating. In the
unfortunate event of a fire, corrosion can have three very negative
effects on your fire system.
1. The inner diameter of the pipe can be significantly reduced in size
by things like corrosion nodules, tubercules, or rust, consequently
reducing the amount of water that can flow through this engineered
system. As an example, according to the Friction Loss Formula used in
the NFPA standard for the installation of fire sprinkler systems, a 1/8"
thick layer of corrosion built up in a 2" pipe will double the friction
within that pipe. The same layer of corrosion in a 1" pipe will
quadruple the friction. The constricted pipe cannot flow enough water to
handle the needs of the zone, so the sprinkler heads cannot effectively
control the fire in that area, allowing a fire to grow and spread to other
parts of your facility.
2. Debris inside the pipe, such as rust,
slime, MIL loss, corrosion nodules, etc. can flow with the water to the
sprinkler head, clogging the small orifices in the head that create the
spray pattern, either forcing an uneven pattern or clogging the head
entirely. This exact issue was the cause of a well-documented sprinkler
system failure in a nursing home in Iowa, along with countless other sprinkler system failures. Luckily there were no serious
injuries in the Iowa example, but the fire raged out of control, forced a
complete evacuation of the building, and significantly damaged a large
portion of the facility. Had the system been working as designed, the
fire would have been contained to a small laundry room rather than
spreading throughout the entire center.
3. Dry system pipe that
has been weakened from wall thinning may burst when the system is
activated, preventing much needed water from flowing through the system
as designed, and allowing the fire to rage out of control.
While many may feel that Dry Sprinkler Systems are not susceptible to
corrosion due to the "lack of water" present, that is not true. Dry fire
systems are very susceptible to aerobic MIC, MIL loss, rust scaling,
pitting, and wall loss.
In addition, water pockets are often
found in dry systems as a result of water left over from the required
NFPA tests (even if the system is blown out with air) and from humidity
present in the air inside the pipe. This water then collects in one or
more low spots within the system, and accelerates corrosion..even in galvanized sprinkler pipe. These low
spots exist in pipe due to poor installation practices and typically
have accelerated corrosion rates compared to the rest of the system.
SoniTech NDT is able to map the location of corrosion and water
pockets in your Dry Sprinkler System, allowing you to know which areas
of your system are in need of further attention.
Wet fire systems are very
susceptible to anaerobic MIC, MIL loss, rust scaling, and corrosion build up.
dry systems, where severe pitting or excessive wall loss can some times
be detected visually by dripping water or external rust spots,
corrosion in wet systems often remains hidden from the naked eye, within
the interior or the pipe.
addition, air pockets are often found in wet systems as a result of air
bubbles dissolved in the water collecting in one or more "high spots"
system, or due to poor venting. These high spots exist in pipe due to poor installation
practices or logistical requirements (i.e. following the slope of a roof
line), and typically have accelerated corrosion rates compared to
the rest of the system.
SoniTech NDT is able to map the
location of corrosion and air pockets in your Wet Sprinkler System,
allowing you to know exactly which areas of your system are in need of further
attention and which areas are still good.