Please advise when the IG55 system is designed for 200 bar & when for 300 bar

Our experts we recently asked the following question:-

Please advise when the IG55 system is designed for 200 bar & when for 300bar

This is our answer:-ProInert IG55

It is down to each individual project but usually we would use 300bar on most projects as this would use less cylinders and therefore this would usually be a lower cost. We do however use 200bar on small projects when 300bar systems “over gas” the risk.

300bar systems are a relatively new product and historically there are a lot of 150bar and 200bar Inergen Systems in premises because that was the standard product.

If you are replacing the cylinder on a 150bar or 200bar system we would usually suggest using the same manufacturer and cylinder size/pressure as you would need to check the following:-

1. Flow Calculation to ensure the pipework is correct and replace as required.

2. Check the Over Pressure Vent size and replace as required.Over Pressure Vent

3. Replace the manifolds.

4. Replace the nozzles.


The cost of replacing these items will usually end up higher than replacing like for like but it’s worth checking.

If you are needing to replace the cylinders and you are having difficulty replacing like for like then replacing with another manufacturer is possible but again try to use the same size/pressure cylinders. You will still need to check and replace the items above but you should not have to change the Over Pressure Vent or pipework.


If you have a question that you need answering regarding Fire Suppression and Detection Systems just click on the “Ask The Experts” now.


  1. Please advise if two (2) different type of high pressure gas (eg Inergen & Argonite) being used in a single fire zone, ie Inergen at room space and Argonite at raised floor space?

    • Although you could use two different Inert gases i.e. in the same space one in the floor void and one in the room, it would be unusual to do this unless one system is existing and the other is new.

      Each volume will need to be calculated separately and treated separately. The actuation will need to be kept separate which can cause issues with monitoring the solenoid.

      So it can be done but make sure you have it all calculated separately.

Leave a Reply