2 replies to this topic

[Dilu]

Hi

 

I have designed Fire protection system for Condensate oil tanks for seal fire case and foam solution is provided via fixed tank with ejector (closed system). Upon heat detection SDVs will open up (Normally closed) the foam pourers present at tanks. Kindly tell me if in case of pneumatic failure the SDV should be Fail Close or Fail open ??????

[ankur2061]

AdilFaheem,

 

If your valves on the foam system distribution piping are automated, they should normally be fail open. However, as you say if these are pneumaticlly operated valves and there is an air pressure loss they will open and inject foam even though there may be no fire thereby contaminating the tank contents protected by the foam system.

 

How to deal with this situation?

 

First of all, all automated systems in the Active Fire Protection System should have an independent source of power and / or utility from the main plant / unit to prevent loss of power / utility to a system which is the utimate protection for life and property. The penumatically automated valves you are mentioning should have their own air volume bottles with an independent air supply to prevent pneumatic pressure failure in case the main plant / air supply is disrupted. If you do this, you will ensure that main plant / unit air failure is eliminated as a cause for the automated valves to fail-open in case of air pressure loss.

 

Hope this helps.

 

Regards,

Ankur.

[Dilu]

Thanks sir... got it.