5 Year Automatic Sprinkler Maintenance – Internal Pipe Exams, FDC backflush & Gauge Replacement

Christopher Moye
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“Mr. Customer, your sprinkler system is due for it’s five year maintenance. When would you like us to take care of it for you?”

We have all been there. We dropped the car off at the dealership or mechanic to have an oil change and a tire rotation. Then you get the phone call an hour later. “Did you know that your vehicle is due for its scheduled maintenance?” Of course we didn’t know, but all we can think is, “How much is this going to cost me?” We are told there are belts, and modules, and filters and, and, and that all needs to be addressed in order to keep up with our maintenance. Though the surprise of an unexpected expense isn’t necessarily a joy to deal with we all have a basic understanding that keeping up with maintenance saves trouble and reduces problems down the road thereby costing us less. The question we should be asking ourselves in the situations is, “How much will this cost me if I don’t do it?”

Just like our vehicles, automatic sprinkler systems, have defined maintenance intervals. Piping, valves and other devices can become obstructed by foreign materials or corrode to the point where they might leak or fail under pressure. And that can put lives and property at risk. Much of a sprinkler system’s fire-control performance is dictated by the available water supply. The basic principle of a hydraulically designed water-based sprinkler system is that the peak flow and pressure demand are no greater than the available supply. If an inadequate flow or system pressure is delivered, the sprinkler system is likely to operate improperly, possibly allowing the fire to spread

The 5 year maintenance items are essentially comprised of 3 pieces: Fire Department Connection Piping Hydrostatic Test (back flushes), Internal Pipe Exams, and Gauge recalibration or replacement.

1. Internal pipe inspection

NFPA 25 requires an internal inspection of fire sprinkler system piping every five years. This is to be conducted to inspect for the “presence of foreign organic and inorganic material.” Foreign materials can cause obstructions to pipe and sprinklers.
The way this is conducted is that a section of the piping is removed OR a sprinkler head is removed and a visual inspection of a length of the internal piping is inspected (with a camera in most cases) to ensure that there is no build up and/or deterioration inside the system. For the sprinkler system to work properly and effectively, water needs to flow without obstruction through the pipes and heads.

2. Fire Department Connection Piping Hydrostatic Test (Backflush)

According To NFPA 25 “Hydrostatic tests of not less than 200 psi (13.8 bar) pressure for 2 hours, or at 50 psi (3.4 bar) in excess of the maximum pressure, where maximum pressure is in excess of 150 psi (10.3 bar), shall be conducted every 5 years on manual standpipe systems and semi-automatic dry standpipe systems, including piping in the fire department connection. “.

The outside of the building has the fire department connections that tie into the automatic sprinkler systems and standpipes for the building. The Fire Department will connect to with a hose that is then connected their truck for its high pressure pumping ability and then to a city hydrant for additional water pressure through the sprinkler system as well as the standpipes inside the building that the fire fighters may need to hook their hoses to.

It is not uncommon for these connections and pipes to have debris and litter in them so this maintenance item is to ensure that when they are needed they will be free from obstructions and water will flow as appropriate. To conduct the back flush, the system is disassembled, the valves are reversed, it is reassembled and water is flowed in reverse to flush out the pipes. Once this is completed the system is taken back apart, the valves reversed back to normal, and reconnected.


3. Replacement of Gauges

The gauges are an important facet of the sprinkler system. These gauges are mechanical devices on the sprinkler system that provide showing water supply pressure and installation or static pressure. The life expectancy of a pressure gauge is generally 10 to 15 years. Since many of a fire sprinkler system tests and inspections rely on the accuracy of the system’s pressure gauge(s), they shall be periodically tested or replaced. According to NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, gauges shall be replaced every 5 years or tested every 5 years by comparison with a calibrated gauge. Gauges not accurate to within ±3% of the maximum (full scale) gauge reading shall be recalibrated or replaced. To recalibrate the gauges it requires taking them off the system (installing a temporary replacement) sending them to a third party for recalibration and then reinstalled. Most companies and end users opt for just replacing the gauges as the cost for doing so is minimal.

So now that we know a little more about the maintenance and what is needed let’s revisit the question of “How much will this cost me if I don’t do it?”.
Sprinkler Systems are designed to slow or stop the spread of fire, saving lives and reducing property damage. According to NFPA the top reasons for water-based sprinkler failure are:

  1. System was manually shut-off early.
  2. Wrong type of system for hazard.
  3. Water discharged, but the water did not reach the fire.
  4. Lack of maintenance.
  5. System components are damaged.

4 out of the top 5 reasons listed could be addressed with regular inspections and maintenance. Insurance companies offer discounts for facility owners that install sprinkler systems, and many will offer a discount if the building owner can provide proof that it is regularly maintained. Here at Guardian Security we provide a comprehensive Automatic Fire Sprinkler inspection and maintenance service.

Contact us to schedule your Service and Compliance Assessment so we can partner with you to ensure the safety and security of your facility.

Additional Material:

Internal Fire Suppression Systems Hampered by Inadequate Fire Attack Hose Stream Pressure Fire in a 38-story high-rise building in Philadelphia resulted in the death of three fire fighters, fire extension to nine floors, and severe structural damage to the building. In addition, 24 fire fighters and one civilian were injured in this mostly unoccupied office building. The fire department received the initial alarm from a person located outside the building just before 8:30 p.m. Upon arrival at the scene, the fire fighters observed heavy smoke at the midheight of the building. During the 18-hour effort to control the blaze, interior fire suppression activities were hampered by the loss of electrical power (including emergency power) and inadequate fire attack hose stream pressure. As a result, the fire spread from the floor of origin, the 22nd floor, to the 29th floor by various spread mechanisms. Vertical fire spread was eventually stopped by the 30th floor automatic sprinkler system supplied by fire department pumpers through the siamese connection. One of the major factors contributing to the loss of life and the severity of the fire was found to be inadequate pressures for fire attack hose lines due to the improper setting of the standpipe pressure-regulating valves. The 2011 edition of the standard eliminates the requirement for a hydrostatic test on automatic dry systems. Automatic dry systems are supervised under constant air pressure and the dry valve is subject to annual trip testing. However, semi-automatic dry systems use a deluge valve and are not supervised; thus, the need for the hydrostatic test remains. Paragraph requires a hydrostatic test every 5 years for manual standpipe systems and semi-automatic dry standpipe systems to detect failures before they become catastrophic in nature. Problems with piping integrity in wet systems can be detected by leaks. Similarly, leaks in automatic dry systems are detected by the loss of air pressure and are subject to the 3-year test for air leakage as required by the standard (see However, it is not possible to detect leakage within manual dry and semi-automatic standpipe systems, which are more susceptible to corrosion due to the combination of air and moisture in the system. Undetected leaks can lead to failures when the dry standpipe is pressurized.