Gaseous suppression room requirements: enclosure integrity, pressure relief, ventilation and warning signs
A gaseous suppression room must retain gas. Unnecessary openings are sealed, ventilation shuts down before discharge, and walls, slabs and doors withstand discharge pressure. If calculations show pressure exceeding the permissible limit, a relief opening or valve is installed. Requirements are set in section 9 of СН РК 2.02-02-2023 and section 5.4 of СП РК 2.02-102-2022.
Why must the room retain gas?
Gas suppresses fire only while extinguishing concentration is maintained. If it escapes through gaps faster than calculated, concentration falls and flames may return. СН РК therefore prohibits unjustified openings (9.3.1) and requires measures preventing gas escape (9.3.2).
The standard lists self-closing and sealed doors, door closers, sealed cable penetrations, shutdown of ventilation, air heating and air conditioning, and duct dampers.
Permissible room leakage is specified by SP RK 2.02-102-2022 (PDF). The leakage parameter is total permanently open aperture area divided by room volume (3.12). Limits depend on volume (table 9).
| Room volume | Maximum leakage parameter | This means open apertures must not exceed |
|---|---|---|
| up to 10 m³ | 0.044 m⁻¹ | 0.44 m² per 10 m³ |
| over 30 to 50 m³ | 0.022 m⁻¹ | 1.1 m² per 50 m³ |
| over 75 to 100 m³ | 0.016 m⁻¹ | 1.6 m² per 100 m³ |
| over 200 to 250 m³ | 0.011 m⁻¹ | 2.75 m² per 250 m³ |
| over 400 to 500 m³ | 0.008 m⁻¹ | 4 m² per 500 m³ |
| over 7,500 to 10,000 m³ | 0.0022 m⁻¹ | 22 m² per 10,000 m³ |
| nitrogen and argon systems | 0.001 m⁻¹ | 0.1 m² per 100 m³ |
Raised-floor and suspended-ceiling voids are separate zones, with leakage determined individually (table 9 note). If room leakage exceeds the table limit, the system is designed to site-specific technical conditions (5.4.1.12).
Why are a pressure relief opening and КСИД valve required?
During a 10-second discharge, tens of kilograms of gas enter a closed room and pressure rises. Structures and aperture infills must withstand it (СН РК 9.3.4). If calculations show they cannot, a permanently open aperture or device opening during discharge is installed (9.3.3). The latter is a pressure relief valve, КСИД: closed in standby, it preserves enclosure integrity.
Relief opening calculation is a mandatory part of the design (СН РК 9.1.9), using appendix Е of СП РК 2.02-102-2022. The formula includes:
- gas mass and discharge time from the hydraulic calculation;
- maximum excess pressure tolerated by the room structure or equipment;
- a safety factor of 1.2 for liquefied agents (nitrogen 2.40, argon 2.66, Inergen 2.44);
- existing open aperture area, subtracted from the result.
If subtraction gives zero or less, no opening is needed: pressure escapes through existing leakage paths. The formula also shows that weaker structures require greater relief area. A room with plasterboard partitions or a glass door has a lower pressure limit than concrete walls and requires a larger valve.
What happens to ventilation?
Ventilation, air heating and air conditioning must automatically shut down before gas discharge (СН РК 9.3.8), otherwise they extract gas or spread it through the building (9.3.5). Shutdown time must not exceed full evacuation time (9.3.9).
| Requirement | Clause |
|---|---|
| Ducts are fitted with air shutters, dampers or fire dampers | СП РК 5.4.1.14, 5.4.1.17 |
| Shutters and valves close fully within 30 seconds | СП РК 5.4.1.16 |
| Shutters may be omitted if ventilation openings are included as open apertures in the calculation and airflow stops before discharge | СП РК 5.4.1.15 |
| Gaseous suppression and smoke ventilation do not operate simultaneously in the same room | СН РК 4.2.101; technical regulation, clause 150 |
| Ventilation required for process safety is included under site-specific standards | СП РК 5.4.1.47 |
Ventilation is also provided to remove gas after suppression. СН РК excludes it from automatic activation during a fire (4.2.11): it starts manually after suppression ends. Ventilation and re-entry procedures are explained in the article Gas discharged: how to ventilate the room.
Which signs, warnings and interlocks are required?
People must not remain inside during gas discharge. Warnings and interlocks are provided at the entrance and inside.
| What is required | СН РК clause |
|---|---|
| Signs identifying rooms equipped with gaseous suppression | 4.2.75 |
| Visual and audible activation warning inside the room | 4.2.76 |
| Visual and audible warning at the entrance | 4.2.77 |
| Warning in adjacent rooms whose exit route passes through the protected room | 4.2.78 |
| Automatic operation disabled illuminated sign at the entrance | 4.2.79 |
| Door sensor inhibiting automatic actuation when opened | 9.3.7 |
| Indication that automatic actuation is inhibited | 9.5.1 |
| Gas discharge delay for evacuation and ventilation shutdown | 9.5.1 |
| Protection against accidental operation of manual actuators | 4.2.80 |
The design specifies warning devices, signs and locations; the standard defines required signals, not device models.
What should be prepared before installation?
Some requirements are met by the customer or main contractor rather than the system supplier. Review this list before design: it affects gas mass, pressure relief needs and system cost.
- Seal unused openings and holes for cables and pipes in walls and floors.
- Fit a door closer and perimeter seal.
- Provide shutters or fire dampers in ventilation and air-conditioning ducts.
- Gather structural details: wall, partition and door materials, and pressure limits.
- Identify raised floors and suspended ceilings and whether their voids need protection.
- For openable windows, choose automatic closure or an opening warning.
- Plan locations for entrance signs and remote actuation buttons.
- Provide temperature and humidity ranges, occupancy and evacuation route details.
СП РК explicitly identifies the final items as calculation input data (5.4.1.8). With this list, you can request design services, and installation will be carried out by our installation team. All standard clauses referenced in the article are collected in Gaseous fire suppression standards in Kazakhstan.
Frequently asked questions
Can gas protect a room with a raised floor or suspended ceiling?
Yes, if the floor and ceiling voids are included in the design. Leakage is determined separately for each zone (СП РК 2.02-102-2022, table 9 note); openings between zones are ignored if gas is discharged simultaneously. Floor and ceiling information forms part of calculation input data.
Do gaseous suppression modules need a separate room?
A modular system needs no separate room: СП РК 5.4.2.1 permits modules inside or beside the protected room. A centralised cylinder-bank system requires a separate station (СН РК 9.1.10). Modules are installed at least 1 m from heat sources.
Can gaseous suppression be installed in a room with windows?
Yes, if windows are closed during suppression. If openable windows do not close automatically during fire, СН РК requires visual and audible opening warnings to staff (9.3.6). Permanently open vents and grilles count as open apertures in leakage and gas mass calculations.
What temperature is required in a room containing modules?
FireStop modules operate from −10 to +50 °C with humidity up to 80% at 15 °C; 42 bar HFC-125 modules operate up to +40 °C. If winter temperatures fall below −10 °C, modules move to an adjacent heated room. СП РК specifies 5–35 °C for a suppression station (5.4.1.27).