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#121 – What Facility Managers Need to Inspect on a Fire Sprinkler System, Part 5

Posted by Jason Hugo on 8/14/2018 to Valves
Fire Sprinkler Valves

NFPA-required inspections of fire sprinkler system valves 


QRFS has covered the inspections for various parts of a fire sprinkler system in this series: 





While Chapter 5 of NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems specifically covers the items that must inspected on a sprinkler system – including sprinkler heads, pipe and fittings, waterflow alarms, and signage – there are other requirements for components common to all fire protection systems. 

In this fifth piece, we examine the basic inspections needed for fire sprinkler system valves; these are outlined in Chapter 13 of NFPA 25: “Common Components and Valves.”

Are you simply on the hunt for some replacement parts? Use the search function at the top of the page, jump to our large inventory of fire sprinkler components, or see our butterfly valve or trim valve product pages.

Inspecting valves in a fire sprinkler system 


Control valves


The interval for inspecting a control valve – which is any “valve controlling flow to water-based fire protection systems” – depends on whether the valve is secured and monitored:

From the 2017 Edition of NFPA 25

 13.3.2.1 All valves shall be inspected weekly.

 13.3.2.1.1 Valves secured with locks or supervised in accordance with applicable NFPA standards shall be permitted to be inspected monthly.

 13.3.2.1.1 Valves secured with locks or supervised in accordance with applicable NFPA standards shall be permitted to be inspected monthly.

 13.3.2.1.1 Valves secured with locks or supervised in accordance with applicable NFPA standards shall be permitted to be inspected monthly.

 13.3.2.1.2 Valves that are electrically supervised shall be permitted to be inspected quarterly.

 13.3.2.1.3 Control valve supervisory alarm devices shall be inspected quarterly to verify that they are free of physical damage.

 13.3.2.1.4 After any alterations or repairs, an inspection shall be made by the property owner or designated representative to ensure that the system is in service and all valves are in the normal position and properly sealed, locked, or electrically supervised.

The rationale for these varying intervals is simple: control valves must remain in the open position for an automatic fire sprinkler to work. Locking them down or, even better, electrically supervising them with an alarm increases that inspection interval from weekly to monthly, all the way up to quarterly. It pays off in safety, system reliability, and convenience to add these extra security measures.

During the inspection, you must look out for these elements:

 13.3.2.2* The valve inspection shall verify that the valves are in the following condition:

 (1) In the normal open or closed position 
 (2)* Sealed, locked, or supervised 
 (3) Accessible 
 (4) Post indicator valves (PIVs) are provided with correct wrenches 
 (5) Free from external leaks 
 (6) Provided with applicable identification

A post-indicator valve (item 4) is one that “is commonly used as the valve operator for automatic fire sprinkler and standpipe systems, where the system main valve is located underground outside the building.” They must be kept locked in the correct position; when this position is changed, the valve is unlocked and a stored handle is inserted and can be manipulated with an appropriate wrench.

By “applicable identification” (item 6), the code is referring to the fact that each control valve must “be identified and have a sign indicating the system or portion of the system it controls” (NFPA 25: 13.3.1). Furthermore, systems “that have more than one control valve that must be closed to work on a system shall have a sign on each affected valve referring to the existence and location of other valves.” (13.3.1.1)

Alarm check valves and system riser check valves

An alarm check valve “prevents a reverse flow of water from the installation into the fire-pump room, but in case a fire sprinkler is activated (opened) due to fire, the alarm valve will open and permit water flow into the system.” It is one of two configurations used in a wet sprinkler system; the other employs a riser check valve. Either one must be inspected quarterly:

From the 2017 Edition of NFPA 25

 13.4.1.1* Alarm valves and system riser check valves shall be externally inspected quarterly and shall verify the following:

 (1) The gauges indicate normal supply water pressure is being maintained.
 (2) The valves and trim are free of physical damage. 
 (3) All valves are in the appropriate open or closed position. 
 (4) The retarding chamber or alarm drains are not leaking. 

 13.4.1.2* Alarm valves and their associated strainers, filters, and restriction orifices shall be inspected internally every 5 years unless tests indicate a greater frequency is necessary. 

This video from FM Global’s “Know More Risk” series explains the components and function of an alarm check valve …


… and this one explains the system riser check valve configuration:


Preaction valves, deluge valves, and dry-pipe valves


Dry-pipe valves or preaction (sometimes referred to as deluge) valves are found in either dry pipe sprinkler systems or preaction fire sprinkler systems – or both, in the case of double-interlock preaction systems.

Most of the pipe in dry pipe systems is filled with pressurized air or nitrogen that holds the water supply back via a dry-pipe valve; when a sprinkler’s heat sensitive element breaks, it releases the pressurized gas, which lowers the pressure in the system and opens the valve to let water flow. This FM Global video explains the layout and operation of a dry pipe valve:


Dry-pipe valves must be inspected as follows:

From the 2017 Edition of NFPA 25

 13.4.5.1.1 Valve enclosures subject to freezing shall be inspected daily during cold weather to verify a minimum temperature of 40°F (4.0°C).

 13.4.5.1.1.1 Valve enclosures equipped with low temperature alarms shall be inspected weekly.

 13.4.5.1.1.2 Low temperature alarms, if installed in valve enclosures, shall be inspected annually at the beginning of the heating season to verify that they are free of physical damage.

 13.4.5.1.2 Systems with auxiliary drains shall require a sign at the valve indicating the number of auxiliary drains and the location of each individual drain.

 13.4.5.1.3 The dry pipe valve shall be externally inspected monthly to verify the following:

 (1) The valve is free of physical damage. 
 (2) All trim valves are in the appropriate open or closed position. 
 (3) The intermediate chamber is not leaking.

 13.4.5.1.4 The interior of the dry pipe valve shall be inspected annually when the trip test is conducted.

 13.4.5.1.5 Strainers, filters, and restricted orifices shall be inspected internally every 5 years unless tests indicate a greater frequency is necessary.

Preaction systems are similar to dry pipe systems in that most of the piping is filled with air or nitrogen; but a single-interlock preaction system’s deployment is controlled by “an electrically operated valve instead” of a dry-pipe valve held shut by highly-pressurized gas. Double-interlock systems deploy when the electrically-activated valve is triggered and the sprinkler deploys and drops the pressure, opening an additional dry-pipe valve. In non-interlocked systems, either event causes the system to deploy.

The term “deluge valve” is also specifically applicable to deluge systems:

"Deluge systems, as the name implies, deliver large quantities of water over specified areas in a relatively short period of time. These systems are used to protect against rapidly growing and spreading fires. Typically, sprinklers used in a deluge system do not contain thermally sensitive operating elements, and as a result are referred to as open sprinklers."

Thus, the exact inspection requirements that apply to your system depend on what it is, and what it has. 

Preaction and deluge valves have similar but expanded inspection requirements compared to dry-pipe valves; and the needs of the former two are essentially identical to each other:

From the 2017 Edition of NFPA 25

 13.4.3.1.1/13.4.4.1.1 Valve enclosures for preaction/deluge valves subject to freezing shall be inspected daily during cold weather to verify a minimum temperature of 40°F (4.0°C).

 13.4.3.1.1.1/13.4.4.1.1.1 Valve enclosures equipped with low temperature alarms shall be inspected weekly.

 13.4.3.1.2/13.4.4.1.2 Low temperature alarms, if installed in valve enclosures, shall be inspected annually at the beginning of the heating season to verify that they are free of physical damage.

 13.4.3.1.3/13.4.4.1.3 The preaction/deluge valve shall be externally inspected monthly to verify the following:  

 (1) The valve is free from physical damage.
 (2) All trim valves are in the appropriate open or closed position.
 (3) The valve seat is not leaking
 (4) Electrical components are in service

 13.4.3.1.4/13.4.4.1.4 The interior of the preaction/deluge valve and the condition of detection devices shall be inspected annually when the trip test is conducted.

 13.4.3.1.4.1/13.4.4.1.4.1 Internal inspection of valves that can be reset without removal of a faceplate shall be permitted to be conducted every 5 years.

 13.4.3.1.5/ 13.4.4.1.5 Strainers, filters, restricted orifices, and diaphragm chambers shall be inspected internally every 5 years unless tests indicate a greater frequency is necessary.

 13.4.3.1.6 Preaction systems with auxiliary drains shall require a sign at the valve indicating the number of auxiliary drains and the location of each individual drain.

This video from Viking Sprinkler explains the valves and function of a single interlock preaction system, as well as the reset procedure:


A second video from Viking covers a double interlock preaction system:


Pressure-reducing valves


Pressure-reducing and relief valves “are installed to control pressures in fire protection systems. They are usually set to reduce pressures on the system side of the valve to pressures not exceeding 175 psi (12.1 bar), the maximum working pressure for most listed sprinkler system components.”

From the 2017 Edition of NFPA 25

 13.5.1 Inspection and Testing of Sprinkler Pressure-Reducing Valves. Sprinkler pressure-reducing valves shall be inspected … as described in 13.5.1.1.

 13.5.1.1 All valves shall be inspected quarterly to verify that the valves are in the following condition:

 (1) In the open position
 (2) Not leaking
 (3) Maintaining downstream pressures in accordance with the design criteria
 (4) Handwheels installed and unbroken

Also note that NFPA 25 requires an annual inspection of “hose connection pressure regulating devices” and “hose rack pressure-reducing devices” (valves; 13.5.2.1, 13.5.3.1), but this only applies if a sprinkler system is part of a combination sprinkler/standpipe system. If this applies to your system, you will also need to conduct all of the other inspections required for a standpipe. 

Dual Pressure Regulating

A diagram of a dual pressure-regulating device. Source: NFPA 25 Handbook

Fire pump relief valves


Similarly, certain fire pump valves must be inspected if a system has a fire pump, and the intervals correspond with the frequency of conducting a no-flow (churn) test (for circulation valves) and any fire pump test (main pressure relief valve):

From the 2017 Edition of NFPA 25

 13.5.6.1.1 Where installed, circulation relief valves shall be inspected on the same frequency as the no-flow (churn) test.

 13.5.6.1.2 The inspection shall verify that water flows through the valve when the fire pump is operating at shutoff pressure (i.e., churn) to prevent the pump from overheating.

 13.5.6.1.3 On completion of any fire pump test, the closure of the circulation relief valve shall be verified.

 13.5.6.2.1 Where installed, main pressure relief valves shall be inspected during any fire pump test.

 13.5.6.2.2 The inspection shall verify that the pressure downstream of the relief valve fittings in the fire pump discharge piping does not exceed the pressure for which the system components are rated.

 13.5.6.2.3 During the annual fire pump flow test, the pressure relief valve shall be verified to be correctly adjusted and set to relieve at the correct pressure and to close below that pressure setting.


There are different forms of pressure relief valves that all serve to “to prevent excessive pressures caused by changes in the conditions under which the system is operating.” Consulting-Specifying Engineer describes a circulation relief valve:

"A fire pump adds energy to the water passing through it. When no water is discharging, the energy will be in the form of heat added to the water. To prevent water overheating at churn, a circulation relief valve located between the fire pump and fire pump discharge check valve is required to operate at churn pressures, but should not operate when the fire pump is flowing water."

Backflow prevention assembly inspections


In addition, backflow prevention assemblies have pressure regulating valves as well as control valves. They are required in commercial fire sprinklers to ensure that the stagnant water in a sprinkler system doesn’t flow back into the municipal water supply. The inspection intervals vary:

From the 2017 Edition of NFPA 25

 13.7.1.1 Reduced-pressure assemblies and reduced-pressure detector assemblies shall be inspected weekly to ensure that the differential-sensing valve relief port is not continuously discharging.

 13.7.1.2 After any testing or repair, an inspection by the property owner or designated representative shall be made to ensure that the system is in service and all isolation valves are in the normal open position and properly locked or electrically supervised.

 13.7.1.3* Backflow prevention assemblies shall be inspected internally every 5 years to verify that all components operate correctly, move freely, and are in good condition.

 A.13.7.1.3 Where annual maintenance includes an internal inspection performed by a qualified person, this requirement is satisfied.


For a complete list of fire sprinkler valve inspection requirements, click on the preview image below for a full table:

Valve Inspection Table Preview

Click here or on the image above to see the full table. Source: NFPA 25 Handbook

Need to replace a valve? Find the right one for the job


Like all things in life, knowing the type of valve you need is crucial to successfully finding it. At QRFS, we stock high-quality trim valves, control valves, and hose valves that complement most fire sprinkler and standpipe systems, for new installs or repair and replace.

Valve Inventory

A sprinkler system is, at its core, a network of pipes, valves, electronics, and sprinklers.  Many of the valves in a system are found as part of the alarm valve, check valve trim, or riser trim. These are often bundled together and simply called “trim valves.” Trim valves cover many of the common valves found in sprinkler systems including those variously referred to as ball valves, check valves, angle valves, test and drain valves, and more.
 
 
For more information on trim valves, read this article: Guide to Trim Valves for Fire Protection.

We also stock butterfly control valves; you can click here to view our selection. And for more information on butterfly valves and why they are superior to their OS&Y predecessors, read our Guide to Butterfly Valves for Fire Protection.

To be continued: What Facility Managers Need to Inspect on a Fire Sprinkler System


This concludes part five of QRFS’ series on the inspection of commercial fire sprinkler systems – but there is another piece in the works. In the next blog, we’ll explain the inspection requirements of other common components, including tanks, as well as discuss special systems.
If you have any questions about commercial fire sprinklers or need help finding a replacement part, just call us at 888.361.6662 or fill out our contact form

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