pumped lubricators (ratchet type) can be mounted anywhere

ok..simple displacement lubricators will work away from the valve chest at any level but if you move them too far away they dont get hot enough and dont work, mine didnt ! I tend to make realy big ones and make the steam inlet adjustable. remember to fit a drain cock to the bottom of it.

A displacement lubricator will work OK anywhere not too far from the engine intake . Positioning of simple displacement lubricators (ie without feed control or shut off valves ) depends far more on position relative to boiler . Needs to be thought about for particular set ups but it is very easy to get it wrong and have the lubricator feed oil back to the boiler . Sometimes when actually steaming the engine but more commonly when newly shut down after a running session .

Generally speaking mount lubricator as far as possible from boiler and near to engine . Think about shape of feed pipe so that there is no possibility of simple gravity back feed or syphon action into the boiler .

Small simple type displacement lubricators don't work in the way usually described in articles .

Instead of steam neatly condensing and floating tiny amounts of oil out to the engine what actually happens is that the whole lubricator almost immediately on steam turn on gets filled with a foaming sludge of oil , steam and water . This foam has a tendency to expand and will leave the lubricator down any available pipe – not nescessarily the intended one . The flow of steam will usually (not quite always) flush the oily mess in the right direction when engine is running but on shut down it can simply go anywhwere .

Displacement lubricators depend for their action on condensing small amounts of steam so the lubricator itself and the steam bleed pipe to the lubricator have to stay reasonably cool . On a small steam plant the best you can probably do is keep them a bit below boiling point !

Always fit displacement lubricators on at least a short branch pipe from steam pipe where possible .

Full size locomotives using displacement lubricators often have an actual steam condenser made from coiled pipe , a control valve system linked to the regulator , auxilliary control valves and a sight feed system .

Michael Williams

PS: Not quite a lubricator fault as such but a cooling boiler with no open valves can create a partial vaccuum that can suck any loose oil back into boiler from lubricator , the steam pipe or engine itself .

Edited By MICHAEL WILLIAMS on 28/02/2012 11:37:14