FIA WG Gases Chairman Alan Elder, explains how gaseous systems can protect data centres… but they aren’t without a few problems
The Fire Industry Association have now published a new guidance document designed uncover the standards surrounding the design, installation & selection of gaseous fixed fire fighting system pipework.
A fixed gaseous fire fighting system uses a gas based agent to put out a fire by displacing some of the oxygen in the room to suffocate the fire, or by simply removing the heat. The method used is dependent on the type of agent selected.
This type of system will be often found to be used in facilities where delicate and high risk computer equipment could suffer damage from other extinguishing media such as water foam or powder; for example Data Centres. A Data Centre, if this happened, could lose data that would come at a tremendous cost to a business and have a huge knock on effect to other systems and businesses that rely on that data. Also a consideration is the physical cost of losing the hardware itself and having to replace it! Therefore, protection of that facility from fire is imperative to reduce the risk of business interruption.
In almost all gaseous fire fighting installations, the agent is delivered to the protected hazard through a network of pipework. With the installation of these systems you can come across various challenges and ensuring the pipework is correctly designed & specified is important to avoid issues that could affect the safety & effectiveness of the system. For example:
- Mismatching pipe threads
- Improper seals between pipework carrying the gas
- Wrong size pipes
The key thing is knowing what problems there could be and knowing how to avoid those common pitfalls.
The supply of gaseous fire fighting systems requires a number of skills, experience and specific knowledge of the equipment, design codes and the hazards associated with handling high pressure gases.
Incorrect handling of gas containers can be particularly hazardous as they hold gases stored under pressure, as are the pipes that allow the flow of the gas to the hazard area. People need to understand how to install gaseous systems so that the system is not only operational, but safe.Alan Elder
The new document covers the pipework used in gaseous fire fighting systems and identifies the hazards that may arise if there was to be a major failure of any pipe or fitting, such as:
- Release of toxic agents in confined spaces
- Pressure effects
- Structural Damage
- Consequential compromise of extinguishing capability
There are a number of concerns in the industry, especially when it comes to pipework. One of the big concerns is that people can mix up British and American standards. It can happen accidentally as there are standards for pipes in the UK that are different to the ones in the USA.
People do not necessarily realise that pipe fittings manufactured to British standards may not be compatible with fittings manufactured to American standards. It is entirely possible that one installer may be familiar with American Standards, and another familiar with British standards – and if components are mixed on the same system, then there could be some compatibility issues between the different types of fittings which could lead to a decrease in the integrity of the system as a whole.Alan Elder
Alan was keen to stress the importance of sticking to just one standard for any given system and ensuring that the standards are applied consistently. Pipe selection is one of the guidance areas that the document covers. Choosing the wrong pipe or making a mistake in calculating the strength of the pipes could lead to pipes leaking at the joints between each pipe, meaning that the gas may not reach the intended destination.
The guide states that is is important that the pipework from the container storage location to the protected space is professionally installed by trained personnel, who have experience with the installation of gaseous fixed fire-fighting systems. They should also be fully conversant with the manufacturers requirements to ensure the stability of piping during discharge and aware of the forces generated. Where agent storage containers are located outside the protected space, then the pipe routing should be the shortest route possible to the protected space.
Another consideration with the pipework is the way in which the pipes are secured to the building structure which can cause further issues if inappropriate pipe fixings are used, due to the high forces present when a system discharges. Therefore the pipework requires supports that are fit for purpose.
Thankfully the document has a handy chart for installers and designers of gaseous fixed fire fighting systems to refer to, which gives the measurements for the maximum spacing between the supporting hangers, depending on the nominal pipe size, which with the correct selection of the support should prevent any pipes from coming away from the wall and causing any damage.
In summary, the guidance document covers everything a designer or installer of gaseous fixed fighting systems needs to know – the pipe specification for both the actuation lines and the pipework installation, methodologies for connecting the pipes, how to join and seal the pipes, what type of support to use to fix the pipes to the structure, how to avoid corrosion, marking, earth bonding, and testing of the completed pipework installation.
The guidance document is available to download free of charge from the FIA’s website.
Original source – FIA UK