I think I'm banging my head against a wall here. Fail safes, removable links, power lights - pressure components that are suitable... anyone catch my drift?

Maddox10,

We are not building combat robots or bumper cars! We are building pressurized vessels & systems which are all designed to a maximum working pressure which is specified by a manufacturer. In 'your opinion' a 50 bar device is suitable for 69 bar (even if that pressure cannot be reached). The manufacturers maximum working pressure is 50 Bar, hence without any further information from the manufacturer (these are not home built devices we are talking about) we should surely assume that the maximum safe working pressure is also 50 Bar? (and we're not taking burst pressure here)

I do not have opinions when it comes to pressure components, I have a fact that there is a design pressure of X, a design temperature of Y and a test pressure of Z.

I designed my gas systems to 90 BarG, hence I can say that everything in my system excluding the CO2 bottles and pressure relief valve is designed to operate or have a safe working pressure of 90 BarG (the hoses, control valves and couplings are rated higher). I know for a fact that the components I manufactured have a safety factor of 4 due to the stress values I used when calculating the minimum shell thicknesses. I know for a fact that the hydro pressure test was successful on the system to a pressure of roughly 128 BarG for 1 hour.

Your opinions are only opinions and you are relying on the in built factor of safety used in the valves construction.

I remember when people thought it was acceptable to use 10 or 16 Bar rams at bottle pressure, along with the plastic tubing and push fittings. This is the same but to a lesser extent - even if 69 Barg cannot be reached.

Regardless of the above, the build rules say 50 BarG components (because 50 Bar is what the manufacturers rate them at) must be protected by a pressure relief device rated to 110% of the working pressure, or independently tested to 120% of the maximum system pressure, which with a 69 Bar relief valve fitted would be around 83 Bar - which I personally consider to be too low.

The gas system I put into Mute complies with the build rules - do you yours? Or is it just in your opinion that they do?

Perhaps the rules do need changing so that I can skim 2 or 3mm off the CO2 bottles (in 'my opinion' they're over rated anyway) and thin the other components down too I can throw more armour on then!