[jcuknz]

Tried searching the web but only find very confusing stuff but there must surely be a figure witch multiplied or divided by will convert a bar amount into psi

 

[StuB]

Try using

http://www.onlineconversion.com/pressure.htm

Which gives a converion

1 pound/square inch = 0.0689475728 bar

or

1 bar = 14.503773801 pound/square inch

Stu

 

[John Webb]

A close approximation is 1 Bar = 15 psi. This is only around 3% out (better than the accuracy of most steam pressure gauges) and is an easy figure to use if you don't have a calculator to hand.
Regards,
John Webb

 

[Clunk]

I've always used 16psi to 1 bar and only recently found out it was 15psi. No idea why.

 

[railstimulator]

The bar is defined using the SI unit pascal, namely:
1 bar ≡ 100,000 Pa.
1 bar is therefore equal to:
100 kPa (in SI units)
1×105 N/m2 (alternative representation in SI units)
1,000,000 dyn/cm2 (barye) (in cgs units)
0.987 atm
14.5038 psi absolute
29.53 inHg
750.06 mmHg
750.06 torr

1 bar = 14.5psi = 29.5 inHg =1013.2 mb.

1013.2 mb = standard pressure at sea level as used in weather forecasting and shown on your barometer. So high pressure is when the reading is above 1013.2 and low pressure is when the reading is below 1013.2

 

[jcuknz]

Thank you for your replies to my question ... caused by a wish to know what pressure my locos operate at.

Only tested Dora from Accucraft so far which doesn't come with a gauge so had to make one and in doing I discovered that the Accucraft thread is not M10 but rather MF10 ... fortunately I have both so was able to make a plug for the water filling hole in her boiler and attaching a bit of eighth tube with the gauge on top.... soldering is not one of my skills so I ended up using instant glue.
Anyway according to the PG the safety valve starts blowing of water [ priming ? ] at under 20psi and Dora started to run on the rolling road shortly after .. pressure never reaching 25psi ... at a guesstimate about 20psi.

Mentioned because others might be puzzled at the thread of Dora

 

[Robert Ellis]

You have already been supplied with the information about pressure conversion but I would advise against the use of super glue or any adhesive when dealing with steam even if it is only 20psig. Learn to solder or braze and ensure that you are not injured by a bursting fitting.

 

[Jim Wills]

If I were dealing with Live Steam I would only consider Silver Soldering (a kind of brazing) on pipework and boilers, as well as on gas pipework.

Atmospheric pressure is generally regarded as 14.7 psi which is equal to 1 bar.

Jimo

 

[Bizman]

QUOTE (Jim Wills @ 20 Apr 2015, 21:56) <{POST_SNAPBACK}>Atmospheric pressure is generally regarded as 14.7 psi which is equal to 1 bar.I have always thought that even as a young lad and was puzzled about this 14.5 figure posters are using.

 

[34C]

QUOTE (railstimulator @ 19 Feb 2015, 11:51) <{POST_SNAPBACK}>...1 bar = 14.5psi = 29.5 inHg ... does not equal 1013.2mbar...

1013.2 mb = standard pressure at sea level as used in weather forecasting and shown on your barometer. So high pressure is when the reading is above 1013.2 and low pressure is when the reading is below 1013.2
I believe it arises from the calibration issue that the bar was intended to be equivalent to mean sea level air pressure, but as now calibrated falls short. So a bar = 14.5 psi, but actual mean air pressure at 1.013 bar = 14.7 psi. Blame it on Napoleon.

 

[hoonsou]

Training as a diesel mechanic, I learnt that an atmosphere (bar) was 14.7 lb a sqare inch. (can't find one of those 2 things)