Inspection, Testing & Maintenance

How to Maintain a Water-Based Fire Protection System

By Michael Swahn P.E., MBA, President, Sebench Engineering

Fire protection equipment is a major investment for any facility. When functioning properly, it can save lives, reduce damage to property, limit the interruption of business, and lower insurance costs. A fire protection system that is not properly maintained is a fire protection system with reduced overall effectiveness, and it may even be useless. Seventy-seven percent of sprinkler system failures are due to the systems being shut off or not maintained. These figures should not raise doubts about the reliability of sprinklers; sprinklers have been found to be effective in fighting 96% of fires.*

* (Fire Journal, July 1970; “An Analysis of Automatic Sprinkler System Reliability Using Current Data,” by John R. Hall Jr. PhD., NFPA, February 2, 2006.)
Standards and Guidelines — NFPA 25

The National Fire Protection Agency (NFPA) provides guide- lines and standards regarding inspection, testing, and mainte- nance of wet-pipe sprinkler systems, dry-pipe sprinkler systems, fire pumps, and water storage tanks. The NFPA understands the importance of maintaining fire protection systems — it dedicated an entire standard solely to this issue — Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems (NFPA 25). Unfortunately, like most fire codes, it was written by engineers for engineers, making it difficult to be read and understood by everyone.

NFPA 25 is part of the 2003 and 2006 International Building Code, and has been adopted into law in 46 states. Only Hawaii, Massachusetts, Mississippi, and Missouri have not yet adopted NFPA 25. The law requires that any change, even one as simple as adding another row of storage racks or rearranging office space, requires a qualified contractor, consultant, or engineer to evaluate the adequacy of the sprinkler system.

You should always contact local and state building com- missions for verification of what standards are adopted by a particular municipality or county, and use a reputable loss control engineer to ensure optimal protection.

Developing a Fire Protection Maintenance Program

When first developing a maintenance program for fire protec- tion equipment, the following should be considered:

1. The applicable NFPA standards — NFPA 25 in most cases.

2. Guidelines specific to the facility.

3. The capabilities of employees. Qualified contractors should be hired when needed.

All staff involved should work together to develop a program that works for your company and type of business. Bringing in a loss control and fire protection consultant may also help identify opportunities to lower your risk exposure.

Maintenance — When, How, and by Whom

NFPA 25 specifies a range of inspection and maintenance activities that require various levels of expertise. Facility management is ultimately responsible for ensuring that all fire protection equipment is being properly maintained. The experience level of the employees at a facility will dictate what activities can be done “in house” and what activities must be left to a qualified contractor.

See the table on the opposite page of when, how, and by

whom specific activities should be tested.

Fire Pumps

There are two types of fire pumps — horizontal and vertical. Most often, a pump is powered by a diesel engine. The water used in a water-based fire protection system is stored in a stor- age tank. These components have to be properly maintained on a regular basis to ensure optimal fire protection.

Horizontal Fire Pump

Before a horizontal fire pump is operated, the following should be verified:

1. Check the drip pockets under the packing glands for proper drainage.
2. Check the packing adjustment — approximately one drip per second is necessary to keep packing lubricated.
3. Observe the suction and discharge gauges. Readings greater than the suction pressure indicate leakage back from the system pressure through either the fire pump or jockey pump check valves.

For a horizontal fire pump, the following should be verified on a weekly basis:

Reprinted from FPC/Fire Protection Contractor | | December 2008 edition

1. Read the suction and discharge gauges — the difference between these readings indicates the churn pressure, which should match the rated pressure. The rated pressure can be found on the fire pump nameplate.
2. Observe the packing glands for proper leakage for cooling the packing.
3. Observe the discharge from the casing relief valve on the electric pumps and from the cooling water discharge line on the diesel pumps — adequate flow prevents overheating of the pump ca se.

Vertical Fire Pump

For a vertical fire pump, the following should be verified on a weekly basis:

1. Read the discharge gauge. The gauge pressure plus a lift factor should equal the rated pressure on the fire pump name- plate. To calculate the lift factor, multiply the distance (in feet) between the water level and the fire pump by 0.43. (For example, if the churn pressure on the nameplate is 50 psi and the pump is 10 feet above the water line, then the gauge should read 50 psi minus 4.3 psi, or 45.7 psi.)
2. Observe the packing gland for proper leakage for cooling the packing.
3. Observe the discharge from the casing relief valve on the electric pumps and from the cooling water discharge line on the diesel pumps — adequate flow prevents overheating of the pump case.

An annual flow test of each pump assembly should be con- ducted by a reputable contractor. The contractor should test at the minimum, rated, and peak flow rates by controlling the quantity of water discharged through approved test devices.

Diesel Engine

To ensure that the diesel engine powering a fire protection system is operating in a reliable and optimal way, you should do the following:

1. Observe the discharge of the cooling water from the heat exchanger — if not adequate to prevent the engine from over- heating, check the strainer in the cooling system for obstruc- tions. If still inadequate, adjust the pressure-reducing valve for the correct flow.
2. Check the engine instrument panel for the correct speed, oil pressure, water temperature, and ammeter-charging rate.
3. Check the battery terminal connections for corrosion and clean them, if necessary.
4. After ensuring that the pump has stopped running, check the intake screens, if provided. Also, change the diesel system pressure recorder chart.

Sprinkler System

A sprinkler system is dependent on water. A water storage tank is a crucial part of the system; it needs regular maintenance and inspections in order to ensure proper fire protection.

The water storage tank needs to be inspected daily in cold weather to ensure that it does not drop below 40°F. If the water temperature is continuously monitored, the frequency may be reduced to once a week.

The water level and the condition of the water in the tank should be visually inspected monthly. If the water level is continuously monitored, the frequency may be reduced to once a quarter. The exterior of the tank should also be visually inspected quarterly. In addition, the interior of the tank should be inspected by a qualified contractor every three years for signs of rusting, corrosion, and the collection of debris. If corrosion protection is provided inside the tank, the frequency may be reduced to once every five years.

If a control valve is sealed, it should be inspected weekly. If the valve is locked or has a tamper switch, the inspection fre- quency may be reduced to once a month. The valve inspection should verify that the valves are in the following condition:

Control Valves — Inspect Weekly or Monthly

1. In the normal open or closed position.
2. Properly sealed, locked, or supervised.
3. Accessible.
4. Provided with appropriate wrenches.
5. Free from external leaks.
6. Provided with appropriate signs, such as “Sprinkler System

No. 1” or “Divisional Valve No.1.”

Fire Department Connection — Inspect Weekly or Monthly

1. The fire department connections are visible and accessible.
2. Couplings or swivels are not damaged and rotate smoothly.
3. Plugs or caps are in place and undamaged.
4. Gaskets are in place and in good condition.
5. Identification signs are in place.
6. The check valve is not leaking.
7. The automatic drain valve is in place and operating properly.

Waterflow Alarms — Inspect; Quarterly or Semiannually

Test the waterflow alarms for each sprinkler system quarterly or semiannually using the inspector’s test connection (quarterly for pressure-type switches and semiannually for vane-type switches).

The inspector’s test connection simulates the activation of the most remote sprinkler. The automatic fire alarm system should activate within 90 seconds after the inspector’s test con- nection is fully open. Verify that all the alarms transmitted off the premises were received by the alarm monitoring company.

Main Drain — Inspect Quarterly or Annually

A main drain test should be conducted quarterly or annually, and any time the control valve has been closed, to determine whether there has been a change in the condition of the water supply piping and control valves. The static and flowing (re- sidual) water pressures should be recorded and compared with the previous test results to determine if an obstruction exists.

Control Valves — Inspect Annually

Each control valve should be operated annually through its full range and returned to its normal position. Post indicator valves should be opened until spring or torsion is felt in the rod; this indicates that the rod has not detached from the valve. Post indicating and outside screw and yoke valves should be backed off a one-quarter turn from the fully open position to prevent jamming.

Pressure Gauges — Inspect every five years: replace or calibrate all gauges every five years.

Reprinted from FPC/Fire Protection Contractor | | December 2008 edition

When sprinklers reach the age of 50, a sample set of sprinklers should be submitted to a nationally recognized laboratory for testing to ensure they are in good working condition. A repre- sentative sample set of sprinklers should consist of a minimum of four sprinklers, or 1% of the total number of sprinklers per individual sprinkler sample, whichever is greater. If one sprinkler within a representative sample set fails to satisfy the test requirements, all the sprinklers represented by that sample shall be replaced.

For fast-response sprinklers, testing should be conducted after 20 years of age. Thereafter, the sprinklers must be tested every 10 years (i.e. years 20, 30, 40, etc.)

Dry-Pipe Sprinkler Systems

Enclosure — Inspect daily during cold weather.

Enclosures that are designed to prevent a sprinkler riser from freezing should be inspected daily during cold weather conditions to ensure integrity, and to make sure the enclosure temperature remains above 40°F.

Priming Level — Inspect Quarterly

High priming-water levels can affect the operation of super- visory air or nitrogen pressure maintenance devices. Test the water level as follows:

1. Open the priming-level test valve. If water flows, drain it.
2. Close the valve when the water stops flowing and air discharges. If air discharges when the valve is opened, the priming-water level could be too low. To add priming water, refer to the manufacturer’s instructions.
Quick-Opening Device — Inspect Quarterly

1. Close the system control valve.
2. Open the main drain valve and keep it in the open posi- tion.
3. Verify that the quick-opening device control valve is open.
4. Open the inspector’s test valve. A burst of air from the device indicates that it has tripped.
5. Close the device’s control valve.
6. Return the device to service in accordance with the manu- facturer’s instructions and return the system to service.

Low-Point Drains — Inspect Annually

Low-point drains are provided to collect the condensate in- side the sprinkler piping. Each year, before the onset of freezing weather, all low-point drains should be drained to ensure that there is no condensate that can freeze and damage the sprinkler piping.

Dry-Pipe Valves — Inspect Annually

Dry-pipe valves should be trip tested on an annual basis in warm weather with the control valve only partially open.

Dry-Pipe Valves — Full-Flow Test Every 3 Years

A full-flow trip test generally requires at least two individu- als: one of whom is stationed at the dry-pipe valve, while the other is at the inspector’s test connection valve. If possible, they should be in communication with each other.

A full-flow trip test is conducted in the following manner:

1. Open the main drain valve fully to clean any accumulated scale or foreign material from the supply water piping.
2. Close the main drain valve.
3. Record the system air or nitrogen, and the supply water pressures.
4. Relieve the system air or nitrogen pressure by opening the inspector’s test connection valve completely. Concurrent with opening the valve, both the testers start their stopwatches. If two-way communication is not available, the tester at the dry valve must respond to the start of the downward movement on the air-pressure gauge.
5. The tester at the dry-pipe valve records the air pressure at which the valve trips, and records the tripping time.
6. The tester at the inspector’s test connection valve records the time at which water flows steadily from the test connection. This time is recorded for comparison purposes with previous tests and is not meant to be a specific pass/fail criterion. Note that NFPA 13, the Standard for the Installation of Sprinkler Systems, does not require water delivery to occur within 60 seconds in all cases.
7. When clean water flows, the test is terminated by closing the system control valve.
8. The air or nitrogen pressure and the time elapsed are to be recorded as follows: (a) from the complete opening of the inspector’s test connection valve to the tripping of the valve and (b) from the complete opening of the inspector’s test con- nection valve to the start of steady flow from the inspector’s test connection.
9. Open all low-point drains; close when water ceases to flow.
10. Reset the dry-pipe valve and quick-opening device (if provided) in accordance with the manufacturer’s instructions and the system is returned to service.

Conclusion — Fire Protection Experts

Maintaining fire protection equipment requires expertise and experience. When functioning properly, a properly maintained fire protection system can save lives and property from devas- tating loss.
About the Author:
Michael Swahn P.E., MBA, is President of Sebench Engineering.

Sebench experts are available to conduct a training class at your facility on how to maintain your fire protection equipment. For more information contact: Sebench Engineering, 2167

Eldorado Drive, Atlanta, GA 30345; (678) 222-0551, E-mail:, Website:

Reprinted from FPC/Fire Protection Contractor | | December 2008 edition

Equipment Testing Frequency

Fire Protection Component Activity


Level of Difficulty

Fire Pumps and Water Storage Tanks

Fire pump test



Fire pump test



Water Storage Tank Inspection Water storage tank inspection Water storage tank inspection

Weekly Monthly Every 5 years

Low Low High

Sprinkler Systems

Control valves inspection

Fire department connections inspection

Waterflow alarms test Main drain Flow test Control valves maintenance Flushing piping test

Pressure gauge calibration test

Weekly/monthly Quarterly Quarterly Annually Annually

Every 5 years

Low Low Low Low Low High

or replacement Every 5 years Medium

Sprinklers test Every 50 years High

Dry-Pipe Systems

Enclosure (cold weather) inspection

Daily/cold weather


Priming level (Dry-pipe valve) inspected



Quick-opening devices test



Low-point drains test

Annually – fall


Dry-pipe valves trip test

Annually – spring


Dry-pipe valves full flow trip

Every 3 years – spring