Neometrix / Fire Protection / Gas Fire Suppression System / NMX-GFS-70

NMX-GFS-70 · ENGINEERED-TO-ORDER CLASS — SPECIFY · SURVEY · SIZE · BUILD · TEST · PROVE

Gas Fire Suppression System. The room has to hold the gas.

Name: Gas Fire Suppression System
Brand: Neometrix
SKU: NMX-GFS-70

A gas fire suppression system puts a fire out without water, by filling a whole room with a gas. That works only if the room keeps the gas. A leak that looks small in an empty room can let the gas out before the fire is out.

So the system is built around three things: a room that is measured, not assumed, a release that closes the openings before the gas arrives, and a relief vent for the pressure the discharge makes.

Discuss a gas system Capability note (PDF)

A single gas cylinder bank on a plain white studio background: four tall slim plain light grey gas cylinders standing upright side by side in a galvanised steel rack on a flat steel base, each topped with a brass valve and a small solenoid actuator and a braided stainless steel hose leading up to a common stainless steel manifold header with a flange at each end and a small pressure switch, and no people

Fig · 01 — A gas cylinder bank: four cylinders in a rack, each with a valve and actuator, joined by hoses to a common manifold header — illustrative render.

The room

measured, not assumedleakage tested with a door fan

The hold

designed and testedapart from the discharge

The openings

closed before the gasdampers and doors interlocked

The pressure

let out safelya relief vent sized for the room

Status

engineered to orderno gas system claimed

ISO 9001ISO 14001NFPA 2001 · ISO 14520 reference standards

Overview

Why the whole job is the room.

Because a gas system is only a bank of cylinders until it meets a room, and the room decides whether the gas stays long enough to do its job.

A single gas discharge nozzle assembly lying on its side on a plain white studio background: a short length of bright stainless steel pipe with a threaded union at one end, a machined brass discharge nozzle drilled with a ring of small round orifices at the other end, and one stainless steel pipe support clamp, and no people

Fig · 02 — A gas discharge nozzle on a length of stainless pipe, with a support clamp: the ring of small orifices spreads the gas through the room — illustrative render.

The room has to hold the gas.

What the system is for

It protects a room that water would ruin: a control room, a switch room, an archive, an equipment bay. On a signal it releases a gas into the whole room to put the fire out without wetting what is inside. It suits a cylinder bank with pipework and nozzles, a modular system beside a single room, and a local application for a machine or a panel.

Why the room has to hold the gas

A gas system works by filling a room to a design concentration and keeping it there long enough for the fire to go out and the contents to cool. If the room leaks, the gas leaves and the concentration falls below what was designed. A system that is perfect on the drawing board fails in a room with open gaps.

Why hold time is not discharge time

The discharge is how fast the gas goes in. The hold time is how long it stays. A system can discharge perfectly and still lose the gas, so the two are designed and tested separately.

Why the room is tested, not trusted

The leakage of the room is measured with a door fan, a fan that holds a pressure difference across a doorway. The result goes into the formulae of the standard to estimate the hold time and the peak pressure. A room that has never been tested has a hold time that nobody knows.

Why the room also has to let go

A discharge raises the pressure in a tight room. A room sealed hard enough to hold the gas can be pushed out of its walls or doors. A pressure relief vent opens at a set pressure and lets the excess out, so the room holds the gas and survives the discharge.

Why the openings are closed first

Ventilation dampers and doors are closed, or the fans shut down, as the release is signalled and before the gas arrives. A fan left running or a damper left open is a hole in the room.

Why the release is careful

A gas that puts out a fire is no friend to the people in the room. The release is therefore signalled by more than one detector, and it is preceded by a warning and a delay, with a way to hold it off.

The method

Specify, survey, size, build, test, and prove.

Six steps in a fixed order. Surveying the room before sizing the gas, and testing the room again with the system in place, are the two a quick order skips.

1 · Specify

The room, the hazard, the equipment inside it and the people who use it are stated by the customer, and the agent is chosen to suit them.

2 · Survey

The room is measured: its volume, its openings and its leakage, by a door fan, before a single cylinder is sized.

3 · Size

The quantity of agent, the cylinders, the pipework, the nozzles and the relief vent are sized from the survey.

4 · Build

The cylinders, manifold, pipework and nozzles are built and supported as one installation, and the interlocks to dampers and doors are wired.

5 · Test

The room is tested again for leakage with the system in place, and the release, the delay, the abort and the interlocks are tried.

6 · Prove

The record is kept, and handed over with the system.

Which system for which room

System	How it protects	What to watch
Inert gas system (nitrogen, argon or a blend)	a gas stored at high pressure in cylinders is released into the room and lowers the oxygen until the fire cannot burn	a large volume of gas, so large cylinder banks and a relief vent, and the leakage of the room decides how long the gas is held
Liquefied clean agent system (a halocarbon agent)	a liquefied agent stored in cylinders is discharged quickly through nozzles and vaporises in the room	smaller cylinders and a quick discharge that makes a pressure peak, so the relief vent matters, and the room has to be cleared of the agent and of the products of the fire afterwards
Carbon dioxide system	carbon dioxide stored in cylinders floods the room or a machine and displaces the oxygen	the gas is a hazard to people, so it is used where no one is inside, with the warning and the lock-off treated as part of the design

The step people underrate is the survey of the room. A system sized from the volume of the room alone is a guess about how long the gas will stay.

Work content

What the system contains, element by element.

Read it as a checklist: a system missing a row will put out a fire on paper and not in the room.

A single pressure relief vent on a plain white studio background: a square galvanised steel frame with a mounting flange all round, a row of flat grey steel louvre blades hinged along their top edges, and a spring-loaded counterweight arm with a cylindrical weight on one side, and no people

Fig · 03 — A pressure relief vent: a galvanised frame with louvre blades that lift at a set pressure, and a spring-loaded counterweight arm — illustrative render.

Element	What it does	What matters
Cylinders and rack	store the agent	cylinders in a rack that holds them against the reaction of the discharge, with room to take one out for refilling
Cylinder valves and actuators	release the agent	a valve on each cylinder with a solenoid actuator, and a manual release as a second way of firing it
Manifold and check valves	join the cylinders	a manifold that collects the cylinders into one pipe, with check valves so that a cylinder can be taken off without losing the rest
Discharge pipework and nozzles	deliver the agent	pipework sized for the flow and supported against the thrust, and nozzles placed so that the gas mixes through the whole room
Pressure relief vent	lets the excess pressure out	a vent in the boundary of the room, sized for the peak pressure of the discharge, which opens at a set pressure and closes again
Release panel interface	brings the signals in	the signals from the detectors, the warning and delay, the abort and the manual release, wired to the release solenoids
Dampers and doors	close the room	ventilation dampers and door closers that shut as the release is signalled, and a record that they did
Room survey and door fan test	measure the room	the volume, the openings and the leakage of the room, measured before the design and again after the build
Procedure	fixes the sequence	specify, survey, size, build, test and prove, the same for every room
Testing & documentation	prove the system first	a check of the release, the delay and the interlocks, a leakage test of the room, and a record the customer can inspect

The element that decides whether the system works is the leakage test of the room, because a room that has never been tested has a hold time that nobody knows, and the system can look perfect and still lose its gas.

Full specification — expand

System	Gas cylinders in a rack that holds them against the discharge reaction; a valve on each cylinder with a solenoid actuator and a manual release; a manifold with check valves; discharge pipework supported against the thrust and nozzles placed to mix the gas through the whole room; a pressure relief vent in the boundary of the room; the interface to the release panel, with warning, delay, abort and manual release; interlocks that close ventilation dampers and doors as the release is signalled; a survey of the room and a door fan test before the design and again after the build; a written test plan; and testing and documentation before handover
The One Idea	The room has to hold the gas.
Why The Room Has To Hold The Gas	A gas system works by filling a room to a design concentration and keeping it there long enough for the fire to go out and the contents to cool, so if the room leaks the gas leaves and the concentration falls below what was designed, and a system that is perfect on the drawing board fails in a room with open gaps
Why Hold Time Is Not Discharge Time	The discharge is how fast the gas goes in and the hold time is how long it stays, so a system can discharge perfectly and still lose the gas, and the two are designed and tested separately
Why The Room Is Tested	The leakage of the room is measured with a door fan and goes into the standard's formulae to estimate the hold time and the peak pressure, so a room that has never been tested has a hold time that nobody knows
Why The Room Also Has To Let Go	A discharge raises the pressure in a tight room, so a room sealed hard enough to hold the gas can be pushed out of its walls or doors, and a pressure relief vent that opens at a set pressure lets the excess out so that the room holds the gas and survives the discharge
Why The Openings Are Closed First	Ventilation dampers and doors are closed or shut down as the release is signalled and before the gas arrives, because a fan left running or a damper left open is a hole in the room
Standards	NFPA 2001 is the public standard for clean agent fire extinguishing systems and ISO 14520 is the international standard for gaseous fire-extinguishing systems, and both use a measured leakage of the room to estimate how long the gas will be held. This page prints none of their design concentrations, hold times, discharge times or pressure limits, and no edition year: those come from the standard the customer names and from the room. Approval of a system for a room rests with the customer and the authority they name; none is claimed here
Configurations	A centralised cylinder bank with selector valves, a single-room modular system and a local application for a machine or a panel
Scope Boundary	This page is the gas fire suppression system. It is not a hydrant and pump system, which supplies water (see fire hydrant and pump system), not a foam system (see foam proportioning system and mobile foam trolley) and not a halon facility, which recovers and refills the legacy agent (see halon reclamation and refilling facility). A sprinkler system, a water mist system and a portable extinguisher are different equipment again. No certification is claimed here
Status	Neometrix engineers gaseous fire suppression systems to order, and no delivered gaseous fire suppression system is claimed.

Configurations

One method, three ways to build the system.

The method, the survey of the room and the leakage test are shared. What changes is where the gas is stored and how far it has to travel to reach the hazard.

Centralised cylinder bank

Bank, selector valves and pipe network

One bank of cylinders in a store room that protects several rooms through selector valves and a pipe network, with a main bank and a reserve bank beside it.

Single-room modular system

Cylinders, short pipe run and nozzles

A few cylinders beside one room, with a short run of pipe and the nozzles inside, for the room where a central bank is not worth building.

Local application

A small system aimed at the hazard

A small system for one machine, one cabinet or one panel that discharges at the hazard itself, so it asks less of the room and more of the aim of its nozzles.

And the part that is not equipment at all, yet decides all three: the test plan. It fixes how the leakage of the room is measured, how the release, the delay and the interlocks are tried, and what is recorded. It is written from the room and its openings, not from the cylinders.

Where it is used

Wherever water would do the damage, and the room can be closed.

The common thread is a room whose contents cannot be wetted, and a room that can be closed tightly enough to keep a gas.

Control rooms and switch rooms

Where panels and cabling must keep working, or be left unspoiled, after a fire is put out.

Data rooms and archives

Where equipment and records would be ruined by water and have to stay dry.

Plant rooms and machinery bays

Where a closed room holds machines, pumps and fuel lines that a fire could reach.

Cabinets and panels

Where the hazard is one enclosure, and a small local system is all that is needed.

Watch

See it in motion.

A short walkthrough video of the gas fire suppression system.

FAQ

Common questions.

Longer answers, for readers who want the reasoning.

Q · 01 What does a gas fire suppression system actually do?

It puts out a fire in a closed room without water. When detectors signal a fire, the system warns the room, waits a set delay, closes the openings and then releases a gas from cylinders through pipework and nozzles until the whole room holds a concentration chosen to stop the fire. It then relies on the room to keep that gas for long enough. It does not clear the room afterwards or repair what burned, and it is not a sprinkler or a hydrant.

Q · 02 Why does the room have to hold the gas?

Because a gas system does not attack the fire with a stream. It changes the air in the whole room and relies on that change lasting. A fire that is out but still hot can start again if the gas leaks away too soon. So the system is judged by how long the room keeps the concentration, not only by how fast the gas arrives. A small gap under a door, a duct left open or a cable opening that nobody sealed can empty a room of its gas. That is why the room is measured before the design and again after the build.

Q · 03 How is the room tested?

With a door fan. A fan is fitted in a doorway, the doors and openings are closed, and the fan holds a pressure difference across the room while the airflow it needs is measured. That airflow tells how leaky the room is. The result goes into the formulae of the standard to estimate the hold time and the peak pressure of the discharge. The survey and the test are repeated after the build, so that the room that was designed is the room that was finished, and the record shows both.

Q · 04 Why does a tight room need a relief vent?

Because a discharge pushes a large volume of gas into a room that has been sealed to keep it. The pressure rises quickly. A room that holds the gas well may also hold the pressure, and walls, doors and ceilings can be damaged. A pressure relief vent in the boundary of the room opens at a set pressure, lets the excess out and closes again. It is a trade between two needs: the more tightly the room is sealed to hold the gas, the more important the vent becomes, and it is sized from the discharge and from the measured room.

Q · 05 Is this the same as the hydrant system, the foam system or the halon facility?

No, and the differences are worth stating precisely. The fire hydrant and pump system page covers the water supply: pumps, pipework and hydrants. The foam proportioning system and mobile foam trolley page covers a foam blanket for a flammable liquid. The halon reclamation and refilling facility page covers the recovery and refilling of the legacy agent, which is a filling facility rather than a system that protects a room. This page is the gas fire suppression system. A sprinkler system, a water mist system and a portable extinguisher are different equipment again. It does not replace any of them, and it does not claim what they claim a second time.

Q · 06 Has Neometrix built one of these?

We would rather answer this plainly than let a page imply otherwise. Neometrix engineers gaseous fire suppression systems to order, and no delivered gaseous fire suppression system is claimed. What stands behind the offer is adjacent: Neometrix engineers a fire hydrant and pump system (see the fire hydrant and pump system page), a foam proportioning system (see the foam proportioning system and mobile foam trolley page), a halon reclamation and refilling facility (see the halon reclamation and refilling facility page) and a nitrogen cylinder manifold with pressure control (see the nitrogen cylinder manifold and pressure control system page). The cylinders, valves, actuators, detectors and release panels are catalogue items, bought in, not invented. What Neometrix engineers is the system around them: the survey of the room, the cylinder bank and manifold, the pipework and nozzles, the relief vent, the interlocks, the procedure and the test plan. So the honest position is that the system is engineered to order, the neighbouring disciplines are in the building, and the first system of this exact kind will be built around the customer's own room rather than taken off a shelf.

Q · 07 Which standard applies, and what can the system not do?

NFPA 2001 is the public standard for clean agent fire extinguishing systems, and ISO 14520 is the international standard for gaseous fire-extinguishing systems. Both use a measured leakage of the room to estimate how long the gas will be held. This page prints none of their design concentrations, hold times, discharge times or pressure limits, and no edition year: those come from the standard the customer names and from the room. The system protects a room and keeps a record. It does not certify a room or a system: this page claims no certification or accreditation. No concentration, time, pressure or quantity figure is printed here, and approval for use rests with the customer and the authority they name; none is claimed here.

Q · 08 What do you need from us to quote?

Six things, and most of them describe your room rather than the cylinders. First, the room: its size, its construction, its doors and the openings in its walls, floor and ceiling. Second, the ventilation: the ducts, dampers and fans that open into it. Third, the contents: what is in the room, and what water or the agent would harm. Fourth, the hazard: what could burn, and where. Fifth, the people: who enters, and how they leave. Sixth, the standard the customer names, and the record wanted at handover. From that we come back with a system concept, a written test plan you can check, and a budgetary price.

The neighbouring fire pages, and how they differ from this one.

Three neighbours: one supplies water, one makes foam, one refills the legacy agent.

↗ Water supply

Fire Hydrant & Pump System

Pumps, pipework and hydrants that put water where it is needed - a water system, where this page fills a room with a gas.

↗ Foam for a liquid fire

Foam Proportioning System & Mobile Foam Trolley

Foam concentrate mixed into water in a set ratio to blanket a flammable liquid - a foam blanket, where this page is a gas that fills the air.

↗ The legacy agent

Halon Reclamation & Refilling Facility

A facility that recovers and refills the legacy agent - a filling facility, where this page is a system that protects a room.

Browse all Neometrix product lines.

Get a quotation

Tell us the room, the openings,
and what is inside.

The projects desk replies within two working days with a system concept, a written test plan you can check, and a budgetary quotation. Write to [email protected] or use the form.

Enquire — gas system Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 ENGINEERED-TO-ORDER CLASS — GAS FIRE SUPPRESSION SYSTEM SPECIFY · SURVEY · SIZE · BUILD · TEST · PROVE — THE ROOM HAS TO HOLD THE GAS ENGINEERED IN NOIDA · INDIA