Quick answer: SMS-227 is S-TEC VINA's automatic-activation gas fire extinguisher using HFC-227ea (FM-200). It discharges automatically when the temperature reaches 68°C, with no control panel required. Under Clause 5.1.3 of TCVN 3890:2023, it may be used in place of an automatic gas fire suppression system in normally unoccupied areas of ≤ 100 m².
- Cylinder sizes: 10 litres (4 – 8 kg fill) and 15 litres (7 – 15 kg fill)
- Working pressure: 25 bar at 20°C
- Discharge time: ≤ 10 seconds
- Connection: up to 15 cylinders, simultaneous discharge
- Circulation licence: No. 154/PCCC under Decree 105/2025/ND-CP
1. Where is the SMS-227 automatic-activation fire extinguisher used?
SMS-227 is designed for electrical rooms, electrical risers and other small areas where water, powder or foam suppression is unsuitable because it can damage electrical and electronic equipment. The cylinder is compact and wall-mounted, with no cylinder room or long piping network required.
| Application | Notes |
|---|---|
| Electrical risers in buildings | Narrow space, normally unoccupied |
| Generator rooms, electrical rooms | High-value electrical equipment; secondary damage must be minimised |
| Telecom BTS stations | Small, dispersed stations, usually unmanned |
| Solar power plants | Inverter rooms, substation control rooms |
| Small server rooms, cash vaults | Small, isolated areas that need automatic fire suppression |
| Renovation projects and retrofit installations | No piping network or cylinder room required |
When not to use SMS-227: areas larger than 100 m² or requiring more than 15 cylinders, and areas that are normally occupied (outside the scope of Clause 5.1.3, TCVN 3890:2023). In these cases, consider the SFS-200 piped HFC-227ea gas fire suppression system.
2. Legal basis and applicable standards
| Regulation / standard | Application to SMS-227 |
|---|---|
| TCVN 3890:2023, Clause 4.10 | Defines areas that must be fitted with an automatic fire suppression system (Appendix A1) |
| TCVN 3890:2023, Clause 5.1.3 | Normally unoccupied areas of ≤ 100 m² may use automatic-activation fire extinguishers in place of an automatic fire suppression system |
| TCVN 12314-2:2022 | Standard for automatic-activation gas fire extinguishers; Clause 5 covers installation |
| TCVN 7161-9:2024 | HFC-227ea agent quantity calculation |
| TCVN 8366:2010 | Pressure vessels – design and manufacturing requirements (cylinder shell) |
| Decree 105/2025/ND-CP | Circulation licence No. 154/PCCC |
| HFC-227ea agent certification | UL Listed (EX28624), FM Approved |
| Management systems | BS EN ISO 9001:2015, BS EN ISO 14001:2015, ISO 45001:2018 |
What does TCVN 12314-2:2022 require for automatic-activation gas fire extinguishers?
TCVN 12314-2:2022 is the Vietnamese national standard for automatic-activation fire extinguishers; Part 2 covers gas fire extinguishers. For installation, Clause 5 of the standard requires:
- Cylinders must be installed in accordance with the technical specifications declared by the manufacturer and tested to TCVN 12314-2.
- Cylinders must stay within the manufacturer's declared limits for installation height and coverage area.
- The discharge nozzle must be no more than 300 mm below the ceiling of the protected area.
- The heat-sensing element must be installed no higher than 9 m and 0.08 – 0.4 m below the ceiling.
3. Operating principle
- Detection and activation: the cylinder valve uses a fast-response heat-sensing glass bulb rated at 68°C. The valve assembly has 360° impact protection.
- Discharge: when the bulb bursts, HFC-227ea discharges through the 180° nozzle mounted on the valve, with a 5 m protection radius and a discharge time of ≤ 10 seconds.
- Multi-cylinder clusters: when any cylinder in the cluster activates, the remaining cylinders are triggered to discharge simultaneously by pressure through DN6 copper tubing, so the full agent quantity is discharged within 10 seconds.
- Signalling to the fire alarm system: each cylinder provides 2 voltage-free contact supervisory signals: fault signal when cylinder pressure drops by 10% or more, and a discharge signal from the pressure switch (NO, 3A/24VDC), used for fire notification and to control other building systems such as shutting down air conditioning and ventilation fans.
Extinguishing agent: HFC-227ea (FM-200) is stored as a liquefied gas, superpressurised with nitrogen to 25 bar. The agent is colourless, odourless, electrically non-conductive and leaves no residue after discharge, and is suitable for Class A and B fires and higher-hazard Class A (HA) areas. The post-discharge concentration is calculated not to exceed the NOAEL of 9.0%, so it does not affect people.
4. Technical specifications of the SMS-227 10 L and 15 L cylinders
| Specification | SMS-227-8L | SMS-227-15L |
|---|---|---|
| Cylinder capacity | 10 litres | 15 litres |
| HFC-227ea (FM-200) fill range | 4 – 8 kg | 7 – 15 kg |
| Cylinder diameter | 210 mm (±1%) | 235 mm (±1%) |
| Height | 470 mm (±1%) | 550 mm (±1%) |
| Empty cylinder weight | 7,5 kg (±5%) | 9,6 kg (±5%) |
| Working pressure (fill pressure at 20°C) | 25 bar | 25 bar |
| Maximum working pressure | 40 bar | 40 bar |
| Discharge time | ≤ 10 seconds | ≤ 10 seconds |
| Discharge nozzle | 180°, protection radius 5 m | 180°, protection radius 5 m |
| Activation | Automatic, heat-activated at 68°C | Automatic, heat-activated at 68°C |
| Multi-cylinder connection | Up to 15 cylinders, total length ≤ 70 m | Up to 15 cylinders, total length ≤ 70 m |
| Cylinder pressure supervision | Pressure gauge with supervisory contact (NO) | Pressure gauge with supervisory contact (NO) |
| Cylinder shell | SG295 steel (JIS G3116) / HP295 (GB 6653), 2.6 – 3 mm thick, red powder coat | Same as the 10 L cylinder |
How to read the model code: the number in the code (8L, 15L) is the maximum fill in kg. The SMS-227-8L has a 10-litre capacity and holds up to 8 kg of FM-200; the SMS-227-15L has a 15-litre capacity and holds up to 15 kg of FM-200.
Need the full SMS-227 catalog with all specifications and cylinder-cluster schematics? Contact S-TEC VINA to receive the latest catalog.
5. How to calculate the agent quantity and number of SMS-227 cylinders
The HFC-227ea quantity is calculated to TCVN 7161-9:2024, based on room volume and fire hazard class. The table below applies to areas with a minimum temperature of 20°C.
| Fire hazard class | Minimum design concentration | Agent quantity required (kg/m³) |
|---|---|---|
| Class A surface fires (wood, polymers, PP/ABS plastics) | 7,9% | 0,626 |
| Higher-hazard Class A (HA), such as electrical rooms | 8,5% | 0,678 |
| Class B (flammable liquids, heptane) | 9,0% | 0,722 |
Safety limits: The NOAEL (No Observed Adverse Effect Level) of HFC-227ea is 9.0%; the LOAEL (Lowest Observed Adverse Effect Level) is 10.5%. The fill quantity is calculated so that the post-discharge concentration does not exceed the NOAEL.
4 calculation steps with an example
| Step | Example: electrical room 2.5 m × 2.7 m, 3.2 m high |
|---|---|
| 1. Identify the fire hazard class (A, B or HA) | Electrical room: select HA, 8.5% concentration |
| 2. Calculate the volume (minus fixed impermeable structures) | V = 2,5 × 2,7 × 3,2 = 21,6 m³ |
| 3. Calculate the agent quantity | m = 21,6 × 0,678 = 14,65 kg |
| 4. Order | 01 × SMS-227-15L-15.0 cylinder (15 L cylinder filled with 15 kg HFC-227ea) + 01 × STV-PS discharge pressure switch. Wall bracket supplied with the cylinder |
How many m³ does one 8 kg or 15 kg FM-200 cylinder protect?
The volume one cylinder protects equals its agent fill divided by the agent quantity required per m³ (per the concentration table above, minimum temperature 20°C):
| Agent fill | Class A (0.626 kg/m³) | HA (0,678 kg/m³) | Class B (0.722 kg/m³) |
|---|---|---|---|
| 4 kg (10 L cylinder) | 6,4 m³ | 5,9 m³ | 5,5 m³ |
| 6 kg (10 L cylinder) | 9,6 m³ | 8,8 m³ | 8,3 m³ |
| 8 kg (10 L cylinder) | 12,8 m³ | 11,8 m³ | 11,1 m³ |
| 10 kg (15 L cylinder) | 16,0 m³ | 14,7 m³ | 13,9 m³ |
| 12 kg (15 L cylinder) | 19,2 m³ | 17,7 m³ | 16,6 m³ |
| 15 kg (15 L cylinder) | 24,0 m³ | 22,1 m³ | 20,8 m³ |
For larger volumes, use a cluster of linked cylinders. For example, a cluster of five fully filled 15 L cylinders protects about 120 m³ for Class A. For a quick calculation, use the HFC-227ea agent quantity calculator for the SMS system.
6. Installation requirements for the wall-mounted SMS-227 FM-200 cylinder
Under Clause 5 of TCVN 12314-2:2022, cylinders must be installed within the technical limits declared and tested by the manufacturer.
- Area height: areas up to 5.5 m high use one tier of cylinders (maximum installation height 5.42 m); areas higher than 5.5 m (total height ≤ 9 m) use two tiers, each up to 5.5 m.
- Sensor position: 0.08 – 0.4 m below the ceiling of the protected area; sensor installation height no more than 9 m.
- Discharge nozzle: no more than 300 mm below the ceiling; can be mounted on the valve assembly or installed remotely from the cylinder within tested limits.
- Cylinder layout: protection radius R = 5 m; maximum spacing between cylinders L = 6 m.
- Mounting: cylinders are supplied with a wall-mounting kit or can be mounted on a support frame.
7. Limitations and conditions
- Scope of use: using automatic-activation cylinders in place of an automatic gas fire suppression system under Clause 5.1.3 of TCVN 3890:2023 applies only to normally unoccupied areas of ≤ 100 m².
- Heat activation: the cylinder discharges when the temperature at the sensing bulb reaches 68°C.
- Interlocks: to provide fire notification and control air conditioning and ventilation on discharge, connect the discharge signal to the building fire alarm system.
- Installation limits: cylinders must be installed within the manufacturer's declared limits for height and coverage area; up to 15 cylinders per cluster, total connection length ≤ 70 m.
- Agent fill: calculated from the volume and fire hazard class of each area, ensuring the post-discharge concentration does not exceed the NOAEL.
8. Ordering information
| Part number (P/N) | Description |
|---|---|
| SMS-227-15L-xxx | 15 L cylinder with cylinder valve and pressure gauge with integrated supervisory contact. xxx = calculated agent fill (kg) |
| SMS-227-8L-xxx | 10 L cylinder with cylinder valve and pressure gauge with integrated supervisory contact. xxx = calculated agent fill (kg) |
| ASy | Connection kit for a cluster of y cylinders (from 1 up to 15 cylinders) |
| STV-PS | Discharge pressure switch |
| SMS-PK1 | Installation kit for 01 cylinder |
Send your floor plan for S-TEC VINA engineers to calculate the number of cylinders or to request the SMS-227 catalog.
9. How does S-TEC VINA supply SMS-227?
SMS-227 is researched, developed and manufactured by S-TEC VINA Co., Ltd., a Vietnam – Korea joint venture. The product holds circulation licence No. 154/PCCC under Decree 105/2025/ND-CP. The system has a simple configuration, fast installation and short lead times, and cylinders can be refilled after discharge.
Frequently asked questions
Does the SMS-227 automatic-activation fire extinguisher need a power supply?
No. The cylinder activates itself via a heat-sensing glass bulb at 68°C. The two supervisory signals (fault and discharge) are voltage-free contacts for connection to the fire alarm system.
How many m³ does one 15 kg FM-200 cylinder protect?
An SMS-227-15L filled with 15 kg protects about 24.0 m³ for Class A, 22.1 m³ for HA areas and 20.8 m³ for Class B (minimum temperature 20°C). A 10 L cylinder filled with 8 kg protects about 11.1 – 12.8 m³.
How much HFC-227ea does an electrical room need?
Electrical rooms fall under higher-hazard Class A (HA), requiring about 0.678 kg/m³ at 20°C per TCVN 7161-9:2024. For example, a 21.6 m³ room needs about 14.65 kg, i.e. one 15 L cylinder.
What size is the SMS-227-8L cylinder?
The SMS-227-8L has a 10-litre capacity and holds up to 8 kg of HFC-227ea. The number in the code is the maximum fill, not the capacity.
Is SMS-227 safe for people?
HFC-227ea is a colourless, odourless, electrically non-conductive clean agent. The quantity is calculated so that the post-discharge concentration does not exceed the NOAEL of 9.0%. The substitution basis under Clause 5.1.3 of TCVN 3890:2023 applies to normally unoccupied areas.
What is the maximum number of SMS-227 cylinders that can be connected?
Up to 15 cylinders, total connection length ≤ 70 m, spacing between cylinders ≤ 6 m. All cylinders discharge simultaneously within ≤ 10 seconds.
How does SMS-227 differ from the SFS-200 system?
SMS-227 is a local, heat-activated cylinder at 25 bar with a simple configuration, for small areas. SFS-200 is an engineered gas fire suppression system with a control panel and piping network, for larger areas.
Can SMS-227 cylinders be refilled?
Yes. SMS-227 cylinders can be refilled after discharge.
See also: SMS product page – automatic fire extinguisher system, SFS-200 piped HFC-227ea gas fire suppression system, HFC-227ea agent quantity calculator for the SMS system, send an enquiry to S-TEC VINA engineers.
Information in this article is based on S-TEC VINA's SMS-227 technical documentation, updated 10/2026. The product must be used correctly in accordance with the manufacturer's recommendations.
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