Sellers’ Self-Acting Steam Boiler Injector – ca 1929

Sellers’ Self-Acting Steam Boiler Injector – ca 1929

Usage conditions apply
This is a boiler water injector built ca 1929 by the William Sellers & Company, Inc. of Philadelphia, Pennsylvania. Early boilers operated at such low steam pressures that introducing feed water into the boiler could be done by simple pumps that filled elevated reservoirs. The water flowed into the boiler by its own weight. However, as pressures increased it became necessary to force water into the boiler by increasingly powerful pumps.
The William Sellers Company had the U.S. manufacturing rights for the design patented by Henri Giffard (that patent model can be found in the collections and is ID Number MC*309368). Giffard found a way of forcing water into the boiler solely by use of the boiler’s own steam without any other moving parts. The William Sellers Company made a series of improvements in design with the goal of making an entirely self-acting unit. Early injectors required constant hand adjustment to maintain the flow of feed water as the steam pressure and other conditions changed. This injector is based on the design introduced in 1887.
Two separate jets of steam were used in the injector. One was used to maintain a vacuum over the feed water tube so that, even if the water supply was interrupted, the vacuum would restart it. The second steam jet forced the water into the boiler.
Sellers was a prolific inventor, and his most notable work was in the area of standardized screw and bolt threads. One of his patent models, for an oscillating steam engine, is also in the collections and is ID Number MC*251296.
The injector is made of brass and is sectioned to illustrate the internal parts. It is approximately 18 inches long and weighs about 65 pounds. As seen in the image of the injector, feed water enters through the green tube at the bottom with steam entering through the red tube. The water is injected into the boiler from the blue tube at the left. The blue sections seen within the injector are the combining tubes where the steam and water come together. The yellow section is open to atmospheric pressure, and the yellow tube discharges the overflow water.
Object Name
Injector, Steam
date made
1887 - 1927
place made
United States: Pennsylvania
ID Number
catalog number
accession number
Credit Line
Gift of William Sellers & Company, In., Philadelphia, Pennsylvania
Steam Engines
See more items in
Work and Industry: Mechanical and Civil Engineering
Engineering, Building, and Architecture
Power Machinery
Exhibition Location
National Museum of American History
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Add a comment about this object