Every six months or after a system actuation, a system maintenance technician services the wet chemical extinguishing system that protects kitchen appliances, hoods, and the exhaust ducts. The work is conducted in accordance with the manufacturer’s service manuals. Some components and parts are routinely replaced, while others that might cause impairment or failure of the system are also replaced at that time. Knowledge of system parts/components and their purpose is essential in order to ensure the system will function as intended. Here is a description of some of those essential components and parts along with things to keep in mind while performing the semi-annual maintenance of restaurant systems.

NFPA requires that all discharge nozzles be provided with caps or other suitable devices [17A: 4.3.2.1]. As part of the 6-month maintenance service, these components need to be examined. Missing or loose caps and damaged foil seals need to be replaced. Additionally, silicone grease should be applied to caps every 6 months. Here are the most common types of nozzle protection devices in use today.

Rubber Blow-Off Caps

A rubber blow-off cap keeps the orifice of a nozzle free of grease and contaminants, which can interfere with proper agent distribution. An integral part of the blow-off cap is the retaining strap, which attaches to the nozzle. The strap keeps the cap attached to the nozzle after system discharge.

Metal Blow-Off Caps

Metal blow-off caps are sometimes used as substitutes for rubber blow-off caps. A metal blow-off cap is attached to the nozzle with the integral stainless steel wire. The wire keeps the cap attached to the nozzle during discharge and prevents it from falling into or onto an appliance.

Nozzle Caps and Seals

For some system nozzles, a cap and foil seal is used to keep grease and contaminants from accumulating in the nozzle orifice. The foil seal ruptures when agent discharge occurs and must be replaced before the system is put back into service. The foil is held in place by the nozzle cap.

Blow-off Cap Grease

Dow Corning® Silicone Grease No. 111 (P/N SL111) is the recommended grease for both rubber and metal blow-off caps. Grease is applied at the 6-month maintenance interval.NFPA allows penetrations in hoods to be sealed by devices that are listed for such use [96: 5.1.5]. Also, any penetrations that result from the removal of conduit or piping are required to be sealed with liquid-tight sealing devices [96: 10.2.7.2].

NFPA allows penetrations in hoods to be sealed by devices that are listed for such use [96: 5.1.5]. Also, any penetrations that result from the removal of conduit or piping are required to be sealed with liquid-tight sealing devices [96: 10.2.7.2].

“Grease-Tite” Adaptors

Jiffy “Grease-Tite” adaptors are UL listed mechanical fittings that form a liquid-tight seal around distribution piping or detection cable conduit. These adapters are installed wherever there is a need to penetrate a restaurant hood or duct.

Corner Pulley “Grease-Tite” Adaptors

These Jiffy adaptors’ intended use are with a high-temperature corner pulley. Adaptors create liquid-tight seals around 1/2 inch EMT conduit. Typically, these adaptors are needed where a corner pulley is needed to make the 90° change in direction from a detector bracket through the top of a hood.

Seals for Holes in Hoods

Whenever pipe or conduit is removed from a hood, the remaining hole in the hood must be plugged and form a grease-tight seal. UL listed Jiffy Patch “Grease-Tite” Seals are installed to cover un-wanted holes without welding.

Restaurant systems are mechanical, and stainless steel cable is used for actuation of the system, including connections to fusible links and pull stations. Cable is also used to trip mechanical gas valves. To work properly, and with little friction, pulleys with ball bearing rollers are installed to provide a 90° change in direction. Here are some of the most common pulleys used in the industry.

High-Temperature Corner Pulleys

There are two types of high-temperature corner pulley elbows that are installed, whenever a 90° change in direction of conduit is needed within a hood. P/N CP8 has socket connections and set screws for connecting to 1/2 inch conduit. P/N CP5 has compression fittings for connecting to 1/2 inch conduit.

Corner Pulleys with Swing-Covers

All swing-cover corner pulleys are intended for low temperature installations (outside restaurant hoods). P/N CP6 has socket connections and set screws. P/N CP7 has 1/2 inch threaded (NPT) connections.

Tee Pulleys

Tee pulleys are installed where two cables from a mechanical release module each need to make a 90° change in direction. Typically the application is a cable for mechanical gas valve shutdown and cable for connection to a pull station. Tee pulleys are never installed for detection cable applications.

Stainless Steel Cable

FireTech™ aircraft type (7x7) stainless steel cable is used for all restaurant system applications, including connections to fusible links, pull stations, and mechanical gas valve trips. Make sure to have an adequate supply of metal crimps and S-hooks for connections to the stainless steel cable. The tools to use with stainless steel cable are P/N CC093 cable cutters and P/N ST116 crimping tool.

Upon activation of any restaurant system, NFPA requires that the fuel and electrical power that produces heat to the appliances, requiring protection, be shut off [96: 10.4.1]. Shutoff devices require a manual reset [96: 10.4.4].

Mechanical Gas Valves

Upon actuation of a restaurant system, the mechanical gas valve automatically shuts off. The most common type of gas valve is the Trip-to-Close ASCO™ mechanical gas valve (P/N GVB). These valves are available to connect from 3/4 to 3 inch pipes.

Electrical Gas Valves

ASCO™ electrical gas valves (P/N GVC) are the industry standard and come in sizes 3/4 to 3 inch. They are normally closed without power, so the valve is held open when the solenoid is energized. Valves must be installed so the solenoid is vertical and upright.

Manual Reset Relays

A manual reset relay (P/N SRR) is a safety feature and is required where an electrical gas valve is employed. When an electrical gas valve closes, due to system actuation or a power outage, the valve cannot be opened until the reset relay button is pressed.

NFPA requires the wet chemical that is used in the system to be listed for the particular system [17A: 4.6.1]. After any discharge, the piping must be flushed and blown out with dry air or nitrogen [17A: 7.4.3]. The supply of wet chemical for recharging the system needs to be stored in the original closed shipping container [17A: 7.4.4].

Wet Chemical Recharge Agent

Wet chemical extinguishing agent is a solution of water and potassium acetate, potassium carbonate, potassium citrate, or a combination of these chemicals. When the extinguishing agent is discharged onto a cooking appliance fire, soap-type foam is created on the surface of a cooking oil fire (excluding air), extinguishing the fire. Wet chemical recharge agent must match the system manufacturer.

Servicing wet chemical extinguishing systems every 6 months helps ensure the system will work as designed. Your knowledge of how system parts play a role in system operation is critical. Also routinely placing parts, according to the manuals, and replacing potential problematic components and parts is essential to keep the system operational. The system owner can rest assured that your knowledge and compliance with the national standards and the manufacturers’ service manuals will ensure safety and maximizes the ability of the system to extinguish a fire, should one ever occur.

In the early 1990s, the industry was struggling to come up with a method to prove that service was conducted on extinguishers. The earliest requirement in NFPA 10, Standard for Portable Fire Extinguishers, was for an internal, legible marking for rechargeable stored pressure dry chemical extinguishers. That requirement appeared in the 1994 edition. Typically, an adhesive label was attached to the siphon tube or the tube was marked with an indelible marker. But the authority having jurisdiction (AHJ) had no method for checking or verifying. The solution for servicing companies and the AHJ was the development of the “verification of service collar”, which is now required for recharging and maintenance. Here is what you need to know about collars and the code requirements for them.

A collar is required to be installed when an extinguisher undergoes recharging or maintenance, where the extinguisher valve is removed. The collar is manufactured from a single circular piece of uninterrupted material. The collar hole does not permit the collar to be removed unless the extinguisher valve is completely removed. Therefore, several sizes are needed. Collars are required in addition to recharge and maintenance tags.

The main reason for the verification of service collar is to provide convenient external visual proof that an extinguisher was disassembled and that maintenance or recharging was most likely conducted. A missing collar or a collar that is stretched or cut indicates tampering. Extinguishers with missing or suspect collars must undergo a complete internal maintenance. During an annual external maintenance of an extinguisher, remember to check the date on the collar. The date must always be the same as or more recent than the date on the hydrostatic test label. Collars are also an important tool for identifying extinguishers that need service. Tell your customers they should contact you if they notice an outdated, missing, or damaged collar.

Collars are available in four sizes and are color coded. A collar must fit snugly around the neck of the extinguisher, so the correct collar must be selected. Never install an oversized collar onto an extinguisher, as it will not meet the intent of NFPA 10. Make sure the one you install is intended for the extinguisher. If you have any questions, call your Brooks account manager.

Starting with the 2010 edition of NFPA 10, the name of the service company is now required on the collar. Although blank collars are still available from Brooks, they are not code compliant for most states. Every Brooks collar allows the technician to record the month and year with a hand punch. Make sure to have an industrial punch (HP3) or a heavy duty punch (TP5R) available for punching collars. The hole punch holster (HPH) and a chain reel (KC1) are nice accessories for the hole punch and make every technician more efficient on the job.

NFPA 10 Compliant Verification of Service Collars

Since valves are removed for hydrostatic testing and extinguishers are recharged before being returned to service, extinguishers must have collars installed after testing. The reason is that prior to the hydrostatic test, an internal examination of the condition of the cylinder is performed. Since a collar is required for internal examination and for recharging, there is no separate requirement for a collar in the hydrostatic testing chapter.

The safety of extinguisher operators and building occupants relies upon quality service of the extinguishers. Up-to-date, code-compliant collars, with your company name imprinted on them, indicate extinguishers that are reliable and ready for use in the event of a fire emergency.