Since their initial development in the 19th century, sprinklers have been proven to be a very effective means of controlling the development and spread of fire. Their effectiveness is however dependant upon:
It is best practice that sprinkler systems are maintained in good order and that a weekly inspection and test is carried out. This is necessary to regularly check the general condition of equipment and exercise moving components to ensure their reliable operation when called upon in an emergency.
There is a wide range of sprinkler installation types and associated water supply configurations with varying testing and maintenance needs for which a system user needs to obtain specific guidance from a specialist sprinkler system installer / maintenance engineer. This Insight Guide is therefore limited to generic aspects. All items of equipment shall be fully maintained in accordance with manufacturers’ specified criteria.
A competent person who has received appropriate training shall undertake weekly testing. It is recommended to be a person normally present at the premises (employee or site-based maintenance contractor), as such familiarity with the system is beneficial if the need arises for the emergency isolation and draining of any part of the system. At least two people shall be trained and regularly involved with testing to facilitate continuity of testing in the event of holidays or illness.
Upon completion of an installation, it is normal practice for the installing engineers to provide users with the necessary training to enable them to undertake regular weekly testing and know how to isolate and drain the system if needed due to leakage. Most sprinkler system maintenance contractors are happy to provide refresher training at the time of routine maintenance visits.
Regular weekly testing is required to be recorded. Weekly Sprinkler Test Cards are available from RMC, a separate card is needed for each installation. Each card includes space to also record electric motor and diesel engine driven fire pump tests, but these only need to be noted on one card where the water supply feeds more than one installation.
Check that all valves that will isolate an installation or pump are secured in the fully open position. A leather strap (or light chain) and padlock are normally used as a means to deter tampering while providing a clear indication if any interference has occurred, but they can also be easily cut in case of the need for emergency isolation.
In the case of dry or alternate type installations charged with air, the installation air pressure and compressor operation need to be checked. Installation air pressure is normally only a fraction of system water pressure, so any change in the installation pressure to a magnitude similar to the water pressure in the feeding main would indicate the installation has tripped over to water. If an accelerator device has been installed, it is essential that it is correctly set and operational when the installation is on air.
Where a pressure tank forms part of the water supply, the water level and air pressure need to be checked.
In winter, consideration shall be given to the potential risk of frost damage to water charged pipework, necessitating a minimum temperature of 4°C to avoid problems. The correct operation of general space heaters and any pipework trace heating shall be checked. Pump houses in which diesel engine driven pumps are situated require to be maintained at a minimum of 10°C.
Opening the alarm test valve runs water to waste, simulating the operation of a single sprinkler. The time taken for the water motor driven alarm gong to ring is recorded. Any significant change in this should be investigated by the sprinkler maintenance engineer.
Hydraulic Alarm Gong
The time taken varies depending on the size of the installation and the amount of air trapped in the pipe array, but is normally expected within 60 seconds. When an alternate / dry-type installation is charged with air, the bell test is limited to diverting water directly to the alarm gong, resulting in instantaneous ringing.
Where an installation alarm pressure switch provides an electronic alarm to the general fire alarm system and / or a remote Alarm Receiving Center (ARC), the actuation of the pressure switch needs to be verified. If remote alarm communication is normally isolated to facilitate weekly testing, a separate test shall be arranged with the ARC every 3 months without isolation to verify the full operation of the alarm system.
Diesel Engine Driven Fire Pump
The basic operation of fire pumps shall be verified by checking the pump cut in (start) pressure and noting the running pressure under a closed valve condition (no flow). Any significant changes need to be investigated by the sprinkler maintenance engineer.
A check is to be made that there is a flow of water from the pump relief valve, which is frequently used for the cooling system of diesel engine driven pumps.
Electric motor driven pumps shall be run for 10 minutes and diesel engine driven pumps for 30 minutes, this is necessary to ensure the engine reaches a normal working temperature.
Where pump controllers have a manual start facility, the correct operation of this shall also be checked.
Diesel engine lubrication oil level shall be checked, with notice taken that the oil has not become contaminated with water. Fuel tanks shall be regularly topped up, the level should never be left below ¾ full. Battery condition shall be checked.
Although not specifically detailed on the test record card, system pressure maintenance pump (jockey pump) cut in (start) and cut out (stop) pressures shall be checked.
Water storage tank levels shall be checked. This shall include a periodic physical check of the actual water level, as content gauges have frequently been found to be inaccurate.
Planned maintenance of sprinkler systems shall be undertaken by engineers who are familiar with the equipment and required maintenance schedules. Normal practice is for the maintenance of sprinklers, pipework, and all valves to be undertaken by a specialist sprinkler system installer / maintenance engineer. Within the UK, a contractor with LPS1048 or equivalent accreditation is recommended. The maintenance of fire pumps, including diesel engines, and water storage tanks is normally undertaken by specialist engineers, often acting as sub contractors of the primary sprinkler maintenance engineers.
Flow Test Meter
Where the water supply and/or installation control valves are under the control of a landlord, it is expected that they will undertake the relevant testing and maintenance. It is recommended that tenants seek annual verification of this from their landlord, which can be evidenced by copies of their test record cards and specialist service engineers’ reports.
In the case of life safety sprinkler systems, there may be flow switches within a tenant’s demise that they are responsible for testing (quarterly). Unless an electronic test device (e.g., “Zonecheck”) has been provided, this test will need to be undertaken by a sprinkler maintenance engineer, who will need to liaise with the landlord.
Tenants zone isolating valve with “zonecheck” flow switch test device.
To ensure a sprinkler system remains adequate for the current fire challenge, occupiers need to be continuously aware of changes that may impact the effectiveness of sprinkler systems.
This shall include the following key points:
Sprinkler Head Fouled By Plaster
As a minimum, an annual review shall be undertaken and documented by a competent person, normally an engineer from the sprinkler servicing firm.
This shall be supplemented by a quarterly review, but this may take the form of a document completed by the occupier that is returned to the competent person for review.
A sprinkler impairment arises when an automatic sprinkler system is shut off or otherwise taken out of service, either completely or in part, such that it can no longer provide the intended fire protection.
Where all or part of a sprinkler system is impaired for more than 7 hours or outside working hours, RMC must be informed in advance using the RMC Sprinkler Impairment Notification Form, which should be e-mailed to:
techsupport@rmcgrp.com
References
Please contact your RMC Engineer for further information