Over Pressure (Solved)

[Shoddyfrog]

*SOLVED*

I have a Metal Volcano (Copper) which is not erupting due to being 'Over Pressure'
I am using a steam turbine to cool the metal, so the volcano is sealed inside a 3 high room with approx. 197 Kg of steam in top 2 tiles and 615 Kg of crude oil in bottom row of tiles.
I did not realise metal volcanoes could get over pressure, it was still erupting fine as i built the set-up and for a while afterwards, so I don't think it is too much oil, I presume it is too much steam pressure?
How much steam do I need to release? What is the maximum pressure of steam you can have surrounding a volcano?
What is the minimum quantity of steam you need to operate a steam turbine? Is it just the temperature of the steam that matters, not the quantity?

[Shoddyfrog]

Problem solved, it was too much steam pressure.
Some numbers for anyone having same problem:
Reduced steam pressure down to 70 Kg Could not say exactly when volcano stopped being over pressure, maybe has to be less than 100 Kg ?
As for whether a turbine needs a minimum amount of steam, I don't know but I had two volcanoes with the same problem and reduced the steam in one to 50 Kg and turbine still functions fine.
By the way, does anyone know if there is way to calculate how much water per tile to put in initially, in order to end up with say 50 Kg of steam per tile when it boils?
Please don't tell me it is 50 Kg I will feel stupid XD

[GMC]

A steam turbine consumes 0.08 kg of steam per inlet per tick (1/5 second), so it will operate at full power (for the temperature) so long as it doesn't drop below that. Realistically you just need enough water to fill the return pipe with a few kg/m^3 left over (you usually start with a couple of kg/m^3 of atmospheric gases in the chamber, and you want the steam to exceed that).

[Shoddyfrog]

ah OK thanks.
So I was putting far too much water in to start with, I will bear that in mind when building the set up in future. I was trying to minimise the amount of gas in the room to start with, that is why I put so much water in.
Don't really want to have to pump all gas out first, then I would have to either leave the pump in the room after and it becomes over heated, or if I dismantle it, then the dupes will expel CO2 while doing it and I am back to having other gas mixed in with steam again.

[JasonS]

I advise always pumping the steam chamber down to a vaccum before starting up the turbine if possible. It takes a while but its worth it. Especially if you have any gasses in there that are lighter than Steam that will stick to the top of the chamber and block the Turbine inlets.