From one drawing I found the hole was around 1mm, another had 0.6mm.

Thor

Edited By Thor on 30/12/2017 05:23:11

I totally agree with Martin. The problem that I have found with displacement lubricators is that they tend to "gulp" all of the oil as soon as the engine is started so the smaller the hole the better. I find drilling these small holes on the kit that I have available is difficult and Martin gives excellent advice. However, if the engine does gulp the oil too quickly one trick is to insert a suitable piece of wire which is, say 0.25mm dia., into the lubricator outlet which will immediately reduce oil flow. Further experimentation may produce the desired result.

Mick

When I made one, I drilled the hole using a sewing machine needle ground as a D bit, this gave a tapered hole, and I stopped as soon as the point went through. Used a hand drill rather than a powered one.

Ian S C

My theory is that it is a dynamic system, not a static one.

Pressure causes steam to enter the lubricator.

The steam condenses and drops below the oil, allowing more steam to enter, until it raises the oil level level above the hole.

The constant pressure cycling means the oil and steam can gradually change places. If the pressure drops so oil drips out, then when it rises more steam goes in when the pressure rises and back to the start.

I would guess that the death of such an arrangement is if the hole is too long so the oil never gets 'sucked' out the end when the pressure is low or if it is placed too far from the valve chest in a location where the pressure doesn't cycle enough.

Neil

Hi Neil / Fizzy

Thank you for your replies.

Have to say I like your dynamic theory Neil, much the same as I was thinking.

Pressure building up in the lubricator exceeding the incoming pressure of the steam, hence the oil is drawn into the valve chest. I would imagine in some form of misty miasma. Just my thoughts.

Thanks again

Geoff

Well it certainly looks the part, very nice.