Editing Automatic lubricator (section)

==Hydrostatic lubricator==
[[Image:Wakefield Lubricator.jpg|thumb|Hydrostatic lubricator showing sight glasses with oil drops rising through the water]]

The one-piece lubricator body is a [[gunmetal]] [[casting]] and incorporates the condensing chamber, the oil reservoir and the sight-glasses fitted at the front and back of the body. Passages within the body interconnect these areas. The body is fitted with a steam valve, a water valve and oil control valves. In operation, steam enters the condensing chamber and the condensed water passes into the bottom of the oil reservoir and the sight-glass chambers. When the sight-glass chambers have filled with water the oil delivery for each feed, regulated by control valves, is released upwards into the water-filled sight-glass chambers. The rate of delivery, typically two or three drops of oil through each feed per minute, is monitored by watching the progress of the drops as they rise through the water. The oil gathers above the water and passes into the delivery tubes. The body is fitted with a drain for emptying the condensed water from the oil chamber before it is refilled with oil.<ref name=RFH>{{cite book |last1=Harvey |first1=R.F. |title=Handbook for Railway Steam Locomotive Enginemen |date=1957 |publisher=[[British Transport Commission]] |location=London |oclc= 4431123 |pages=127–134}}</ref>

This type of hydrostatic displacement lubricator was made by the Detroit Lubricator Company of the USA. A British patent was granted in 1911 and this lubricator was then manufactured by the [[Vacuum Oil Company]] (later [[Mobil|Mobil Oil]]) as the ''British Detroit Lubricator''. This lubricator was commonly made with either 3,4 or 5 feeds, the center feed on the odd numbered lubricators was often used for supplying oil to the steam end of Westinghouse air compressors.<ref name=Locolub>{{cite book |last1=Skellon |first1=Peter W. |title=Steam locomotive lubrication : its development and practice |date=1997 |publisher=MIC |location=Barrow-in-Furness |isbn=0-9530417-0-0}}</ref>