Mr. Hosford,
I'm not trying to hop on you (because one can't convey tone in a typed statement) but your post prompts me to ask if you realize there is very little difference in the danger presented at 20psi than that at 150psi. If there is any superheated water (above the boiling point at atmospheric but under enough pressure to keep it liquid) left in the lubricator it will propel the oil to places it should not be as it expands about 1600 times. Looking at a steam pressure/temperature chart 20psi gauge steam is shown to be about 259 degrees F while 150psi gauge steam is about 365 degrees F. At either one the oil temperature will be about the same and will make a nasty burn.

The real key is to approach it deliberately and carefully which, if you have been safely refilling at 20 - 50 psi, sounds like the method you've been using. I wish you continued safe operations. mld

Fair comment mld, and I take no offence. I did not explain myself very well when I mentioned lower boiler pressure. My point is that when re pressurising the lubricator after filling, it is easier to gently re pressurise the casting, as it is often difficult to very gently open the steam valve, and then let it rise gradually with the boiler pressure. I think this gives you less chance of potentially damaging shocks to the casting, bullseyes, and gaskets. If you fill the lubricator before even lighting up (oil burners) then the main stop on the turret, the globe valve on the lubricator steam line, and the steam valve on the lubricator will give you three levels of protection from the remaining boiler pressure.

P Hosford

I'm glad you read it in the spirit intended and I now better understand what your point was. Happy Steaming!!.....mld