Hand-Pump Pressure Lubricator
From the collection of National Museum of American History. Free to download, adapt and use — no permission needed.
This is a pressure lubricator designed to force lubricating oil into the steam being supplied to a steam engine for the lubrication of the piston and valves. It forces the oil into the steam main against the pressure of the steam. It consists of a large glass reservoir into which is built a small simple hand pump. By working the handle of the pump the oil is drawn into the pump cylinder and discharged through the screw fitting at the bottom of the lubricator into the steam main or valve chest to which the lubricator is attached. The efficiency of lubricators of this kind depends entirely upon the judgment of the engineer or oiler. They are generally wasteful of oil.
National Museum of American History’s own description