Commercial Kitchen Hood Fire Suppression
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 5
to Rev 6
in Commercial Kitchen Hood Fire Suppression.
---
title: Commercial Kitchen Hood Fire Suppression
…167 unchanged lines
### Wet-chemical agent is a water-based liquid solution and is subject to freezing. {note}
+### The agent cylinder, cartridge, detection, and piping shall be within the temperature range for which the listed system is rated.
+
+### The cylinder and the agent lines shall not be located where they may be exposed to temperatures below the listed minimum, and shall not be exposed to the elevated temperatures near cooking equipment beyond the listed maximum.
+
```datasheet
label: Ambient Temperature Range at Cylinder and Agent Lines
…7 unchanged lines
```
−### The agent cylinder, cartridge, detection, and piping shall be within the temperature range for which the listed system is rated.
−
−### The cylinder and the agent lines shall not be located where they may be exposed to temperatures below the listed minimum, and shall not be exposed to the elevated temperatures near cooking equipment beyond the listed maximum.
−
### The fusible-link or detector temperature rating shall be selected for the expected temperature in the duct and plenum and over each appliance so that the links hold under normal cooking conditions and release promptly on fire.
…12 unchanged lines
### The agent extinguishes a cooking-oil fire by two mechanisms working together: it cools the fuel and surfaces below the auto-ignition temperature, and it reacts with the hot cooking oil to form a thick soap-like foam (saponification) that seals the fuel surface and prevents the re-release of flammable vapors. {note}
+### The agent shall be a listed low-pH, potassium-based wet-chemical solution (commonly potassium acetate, potassium carbonate, or potassium citrate based) as supplied for the listed system.
+
```datasheet
label: Wet-Chemical Agent
…4 unchanged lines
```
−### The agent shall be a listed low-pH, potassium-based wet-chemical solution (commonly potassium acetate, potassium carbonate, or potassium citrate based) as supplied for the listed system.
−
### Saponification is what allows a wet-chemical system to hold a deep-fat fryer fire, where the oil remains hot enough to re-ignite for a long time after the flame is knocked down. {note}
…4 unchanged lines
### High-efficiency cooking appliances (for example energy-efficient deep-fat fryers that retain heat and hold a larger, hotter oil reservoir) and the modern vegetable-based cooking oils that have higher auto-ignition temperatures and longer cool-down times were the reason UL 300 superseded the earlier test standard: older dry-chemical systems could knock down the flame but could not keep the hot oil from re-igniting. {note}
+### The design shall account for the cooking medium and the efficiency of the protected appliances.
+
```datasheet
label: Predominant Cooking Medium / Appliance Hazard
…8 unchanged lines
```
−### The design shall account for the cooking medium and the efficiency of the protected appliances.
−
### The listed system and its nozzle selection shall be appropriate for the appliances and the cooking medium present.
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### A grease-clogged nozzle is a common cause of a failed discharge. {note}
−```datasheet
−label: Nozzle Coverage and Aiming
−type: radio
−options:
− - "Per listed nozzle type, height, aiming, and flow point for each protected area"
−default: "Per listed nozzle type, height, aiming, and flow point for each protected area"
−```
+### Nozzles shall be of the type, orifice, and flow-point rating established by the listed system for the area each protects, and shall be installed at the height and orientation and aimed at the point required by the listing.
+### Each nozzle shall be fitted with the listed blow-off cap or cover that keeps grease and cooking vapors out of the orifice during normal operation and blows off cleanly on discharge.
+
```datasheet
label: Nozzle Blow-Off Caps
…4 unchanged lines
```
−### Nozzles shall be of the type, orifice, and flow-point rating established by the listed system for the area each protects, and shall be installed at the height and orientation and aimed at the point required by the listing.
−
−### Each nozzle shall be fitted with the listed blow-off cap or cover that keeps grease and cooking vapors out of the orifice during normal operation and blows off cleanly on discharge.
−
### Nozzles shall be positioned clear of obstructions that would deflect the agent away from the protected surface and shall not be relocated or re-aimed in the field except as the listing permits.
+```datasheet
+label: Nozzle Coverage and Aiming
+type: radio
+options:
+ - "Per listed nozzle type, height, aiming, and flow point for each protected area"
+default: "Per listed nozzle type, height, aiming, and flow point for each protected area"
+```
+
## Re-Survey and Recommissioning on Appliance Change {toc}
### Because the nozzles are aimed at specific appliances in specific positions, a change to the cooking line can leave an appliance outside its nozzle's coverage or leave a nozzle aimed at empty space, producing a system that appears intact but will not protect the kitchen. {note}
+### The system shall be re-surveyed and recommissioned whenever a protected appliance is moved, added, removed, replaced, or changed in size or type, in accordance with NFPA 96 and NFPA 17A.
+
```datasheet
label: Appliance-Change Recommissioning Requirement
…4 unchanged lines
```
−### The system shall be re-surveyed and recommissioned whenever a protected appliance is moved, added, removed, replaced, or changed in size or type, in accordance with NFPA 96 and NFPA 17A.
−
### The Owner shall be informed in writing that any change to the cooking line — including swapping a fryer for a range, widening an appliance, or shifting the line to make room for new equipment — requires a qualified contractor to re-survey the layout and reconfigure, relocate, or add nozzles and detection before the appliance change is placed in service.
…6 unchanged lines
### A cylinder too small for the total flow points cannot deliver the required agent to every nozzle. {note}
+### The wet-chemical agent shall be stored in a listed cylinder that is part of the listed system, located where it is accessible for inspection, weighing, service, and recharge and within the piping limits of the system.
+
+### The cylinder size shall be selected to satisfy the total system flow points.
+
+### The cylinder shall be secured against movement and protected from physical damage and from temperatures outside its listed range.
+
+### Where the total flow points exceed the capacity of a single cylinder, multiple cylinders shall be manifolded as the listed system permits.
+
```datasheet
label: Agent Cylinder Arrangement
…5 unchanged lines
```
−### The wet-chemical agent shall be stored in a listed cylinder that is part of the listed system, located where it is accessible for inspection, weighing, service, and recharge and within the piping limits of the system.
−
−### The cylinder size shall be selected to satisfy the total system flow points.
−
−### The cylinder shall be secured against movement and protected from physical damage and from temperatures outside its listed range.
−
−### Where the total flow points exceed the capacity of a single cylinder, multiple cylinders shall be manifolded as the listed system permits.
−
## Cartridge Actuation and Regulated Release {toc}
### The cartridge is normally sealed and is punctured by the release mechanism on actuation; the regulator establishes the controlled discharge pressure so that each nozzle delivers its rated flow. {note}
+### The system shall be actuated by a stored-pressure expellant cartridge (commonly nitrogen) that, on release, pressurizes the agent cylinder through a regulated-release assembly and expels the agent through the distribution piping to the nozzles at the regulated pressure the listed system requires.
+
+### The cartridge shall be the type, charge, and size supplied for the listed system, shall be within its service date, and shall be installed and pressurized only as the final commissioning step after detection and the mechanical/electrical release have been verified.
+
```datasheet
label: Actuation Cartridge
…4 unchanged lines
```
−### The system shall be actuated by a stored-pressure expellant cartridge (commonly nitrogen) that, on release, pressurizes the agent cylinder through a regulated-release assembly and expels the agent through the distribution piping to the nozzles at the regulated pressure the listed system requires.
−
−### The cartridge shall be the type, charge, and size supplied for the listed system, shall be within its service date, and shall be installed and pressurized only as the final commissioning step after detection and the mechanical/electrical release have been verified.
−
## Distribution Piping and Nozzles {toc}
### The total piping volume, the number and type of fittings, and the run lengths govern whether each nozzle delivers its rated agent — not an open hydraulic calculation. {note}
+### Distribution piping shall be the type, size, and material required by the listed system, and the total piping volume, the number and type of fittings, and the run lengths shall be within the limits the manufacturer's design and installation manual establishes for the cylinder size.
+
```datasheet
label: Distribution Piping
…4 unchanged lines
```
−### Distribution piping shall be the type, size, and material required by the listed system, and the total piping volume, the number and type of fittings, and the run lengths shall be within the limits the manufacturer's design and installation manual establishes for the cylinder size.
−
### The piping shall be reamed and blown clear of cuttings and debris before assembly, supported to resist the discharge reaction, and pitched and arranged so it drains and does not trap agent.
…12 unchanged lines
min: 1
max: 30
− setpoints: [4, 8, 12, 16, 20, 24, 30]
+ setpoints: [1, 4, 8, 12, 16, 20, 24, 30]
default: 12
```
…8 unchanged lines
### Detection shall be by fusible (eutectic-alloy) links held on a tensioned detection line, or by listed thermal detectors, as the listed system provides.
−### On release of any link or detector, the tension is lost (or the detector signals), the release mechanism operates, and the system discharges. {note}
```datasheet
…5 unchanged lines
default: "Fusible (eutectic-alloy) links on a tensioned detection line"
```
+### On release of any link or detector, the tension is lost (or the detector signals), the release mechanism operates, and the system discharges. {note}
+### Automatic detection shall be provided in the exhaust duct, in the hood plenum, and over each protected cooking appliance, so that a fire anywhere in the protected system actuates discharge.
+
```datasheet
label: Detection Coverage
…6 unchanged lines
```
+### Each link or detector shall carry a temperature rating selected for its location so that it holds under normal cooking and exhaust temperatures but releases promptly on fire; links in the duct and over high-heat appliances carry higher ratings than links in cooler locations.
+
```datasheet
label: Fusible-Link Temperature Rating
…11 unchanged lines
```
−### Automatic detection shall be provided in the exhaust duct, in the hood plenum, and over each protected cooking appliance, so that a fire anywhere in the protected system actuates discharge.
−
−### Each link or detector shall carry a temperature rating selected for its location so that it holds under normal cooking and exhaust temperatures but releases promptly on fire; links in the duct and over high-heat appliances carry higher ratings than links in cooler locations.
−
## Manual Actuation {toc}
…18 unchanged lines
### A mechanical gas valve is commonly preferred where standing pilots are present because it operates without electrical power; an electrically operated valve is acceptable where it fails closed on loss of power or on actuation. {note}
+### On discharge, the system shall shut off the fuel and the electric power to all cooking appliances served by the hood, in accordance with NFPA 96 and NFPA 17A.
+
+### Gas-fired appliances shall be shut off by a listed mechanical or electrical gas valve that closes on system actuation and remains closed until manually reset, so that fuel gas is not fed to a fire the agent has just extinguished.
+
```datasheet
label: Gas Appliance Shutoff
…6 unchanged lines
```
+### Electrically powered cooking appliances shall be de-energized on actuation by a shunt-trip breaker or contactor.
+
```datasheet
label: Electric Appliance Shutoff
…5 unchanged lines
```
−### On discharge, the system shall shut off the fuel and the electric power to all cooking appliances served by the hood, in accordance with NFPA 96 and NFPA 17A.
−
−### Gas-fired appliances shall be shut off by a listed mechanical or electrical gas valve that closes on system actuation and remains closed until manually reset, so that fuel gas is not fed to a fire the agent has just extinguished.
−
−### Electrically powered cooking appliances shall be de-energized on actuation by a shunt-trip breaker or contactor.
−
### Leaving the heat source energized after discharge is a leading cause of re-ignition of a cooking-oil fire. {note}
…2 unchanged lines
### Keeping the exhaust fan running maintains the draft that carries heat, smoke, and any unburned vapors up the duct and out of the building, and the agent is delivered into that moving airstream by the duct and plenum nozzles; an arbitrary fan shutdown can allow heat and products of combustion to spill back into the kitchen. {note}
+### The exhaust fan shall be arranged in accordance with NFPA 96 with respect to its operation on discharge.
+
+### The exhaust fan shall continue to operate after the extinguishing system has discharged unless fan shutdown is specifically required by a listed component of the ventilation system or by the design of the listed extinguishing system.
+
```datasheet
label: Exhaust Fan on Discharge
…5 unchanged lines
```
−### The exhaust fan shall be arranged in accordance with NFPA 96 with respect to its operation on discharge.
−
−### The exhaust fan shall continue to operate after the extinguishing system has discharged unless fan shutdown is specifically required by a listed component of the ventilation system or by the design of the listed extinguishing system.
−
### The exhaust fan shall also be interlocked to operate whenever any heat-producing cooking appliance under the hood is in use, per NFPA 96.
…2 unchanged lines
### The detailed building notification and reporting functions are covered in [[sync/fire-alarm-systems]]; this standard governs only the interface from the cooking suppression system. {note}
+### The system shall transmit its actuation and supervisory condition to the building fire alarm system, in accordance with NFPA 96, NFPA 17A, and NFPA 72.
+
```datasheet
label: Fire Alarm Interface
…6 unchanged lines
```
−### The system shall transmit its actuation and supervisory condition to the building fire alarm system, in accordance with NFPA 96, NFPA 17A, and NFPA 72.
−
### On discharge the system shall signal an alarm to the building fire alarm system so that occupant notification and off-premises reporting occur.
…46 unchanged lines
# Installation {toc}
−## General {toc}
+## The Contractor shall install the system in accordance with this standard, the approved working drawings, UL 300, NFPA 96, NFPA 17A, NFPA 70, and the listed-system manufacturer's design and installation manual.
−### The Contractor shall install the system in accordance with this standard, the approved working drawings, UL 300, NFPA 96, NFPA 17A, NFPA 70, and the listed-system manufacturer's design and installation manual.
+## Where these conflict, the more stringent governs, and no installation shall deviate from the conditions of the listing.
−### Where these conflict, the more stringent governs, and no installation shall deviate from the conditions of the listing.
+## Piping shall be installed to the listed limits, reamed and cleaned, and supported to resist discharge reaction.
−### Piping shall be installed to the listed limits, reamed and cleaned, and supported to resist discharge reaction.
+## Nozzles shall be installed at the listed heights and aiming for the appliances actually present, with blow-off caps fitted.
−### Nozzles shall be installed at the listed heights and aiming for the appliances actually present, with blow-off caps fitted.
+## Detection links/detectors shall be installed at the locations and ratings shown, with the detection line tensioned per the manufacturer.
−### Detection links/detectors shall be installed at the locations and ratings shown, with the detection line tensioned per the manufacturer.
+## The cartridge shall be installed and the system armed only as the final commissioning step after all functions are verified.
−### The cartridge shall be installed and the system armed only as the final commissioning step after all functions are verified.
−
## Signage {toc}
…36 unchanged lines
### Fusible links and metal-alloy detection elements are replaced at each semiannual service, not merely inspected, because the alloy fatigues and accumulates grease over time and a link that does not release promptly defeats the automatic detection. {note}
+### Fusible (eutectic-alloy) links and metal-alloy detection elements shall be replaced at least semiannually, in accordance with NFPA 96.
+
```datasheet
label: Fusible-Link / Detection Element Replacement
…5 unchanged lines
```
−### Fusible (eutectic-alloy) links and metal-alloy detection elements shall be replaced at least semiannually, in accordance with NFPA 96.
−
### Where the system uses listed thermal detectors rather than fusible links, the detectors shall be inspected and tested at the semiannual interval per the manufacturer's instructions.
…48 unchanged lines
## A discharged system leaves the cooking operation unprotected until it is recharged. {note}
+## The Contractor shall provide the spare components recommended by the listed-system manufacturer for keeping the system in service, in accordance with NFPA 17A and the contract documents.
+
+## As a minimum, the Contractor shall provide spare fusible links of each temperature rating installed, spare nozzle blow-off caps, and the means to return the system to service after a discharge with minimum downtime (a spare cartridge and an agent recharge source).
+
```datasheet
label: Spare Parts and Recharge Provisions
…7 unchanged lines
```
−## The Contractor shall provide the spare components recommended by the listed-system manufacturer for keeping the system in service, in accordance with NFPA 17A and the contract documents.
−
−## As a minimum, the Contractor shall provide spare fusible links of each temperature rating installed, spare nozzle blow-off caps, and the means to return the system to service after a discharge with minimum downtime (a spare cartridge and an agent recharge source).
−
## The Owner shall be advised of the agent recharge source and the cartridge and hydrostatic-retest schedule so the system is maintained ready throughout its life.