On Mon, 11 Mar 2019 22:57:15 -0000, Steve Walker wrote:

On 11/03/2019 21:26, Commander Kinsey wrote:
On Mon, 11 Mar 2019 21:13:22 -0000, Steve Walker
wrote:

On 11/03/2019 20:25, Commander Kinsey wrote:
On Mon, 11 Mar 2019 19:14:47 -0000, Tim Watts wrote:

On 11/03/2019 18:49, Commander Kinsey wrote:

So the meter outside my house reduces the pressure? I thought the
pressure was lowered for the whole street, like a substation
reduces the
electricity to 240V.

I had noticed on older houses there's some kind of valve seperate from
the meter (often exposed to the outdoor weather!), presumably nowadays
it's inside the meter.

Your meter has a regulator that drops from an already lowish
pressure to
20mbar.

http://www.gasinfo.uk.com/distribution_page.htm

Wow, 20mbar is damn low, I'm surprised that has the desire to move along
the pipe.

How do things like camping stoves work? I assume the pressure inside a
butane cannister is much higher than that, and I don't think they have
pressure reducers.

I presume that the needle valve and feed to it is sized to be very
restrictive for the simple screw on burners.

For example, I have a twin burner (Tilly) stove. It's fed from a butane
cannister. Since I could operate one or both burners at different
rates, there can't be a limiter anywhere that could work unless it's
clever enough to adjust pressure independant of flow rate. Perhaps the
pressure is quite high, but the taps to control the burners are what
restricts it?

Or a separate restrictors before each valve - probably just the valve
design though.

The bigger ones fed by hose from a Calor cyclinder or the like have
28mBar regulators for butane or 37 mBar ones for propane. The different
pressures allowing for the different calorific values of the two gases
when using the same size jets, so allowing interchanging bottles
depending upon the ambient temperatures. Butane won't gas off from the
liquid on a cold day.

I wasn't aware of that, so I can't use a butane camping stove in winter?

Basically correct. You may get away with it, but when temperatures are
down to about 4°C, the cylinder cools a little further as the gas is
used and it gets the bottle too cold to boil any more gas off. It is not
actually a sudden cut-off, it is a reduction in the rate of boiling and
so the gas flow is too low for the burners.

I didn't know that. I've never used a stove in cold temperatures. So anyone camping in winter uses propane?