Steam Engines

Vapor Motive Company continues the development of the Unaflow steam engine based on the best designs of the past 100 years. We start from the original drawings and encompass improvements from operational experience of legacy engines, new engineering techniques, and incorporate features for modern production techniques, long-life, high degree of serviceability, and overall low life-cycle costs.

Key aspects of VMC’s design are:

VMC Steam Engine Cylinder and Head
Uniflow path of steam through the cylinder to the extent steam conditions allow and steam heated heads to minimize initial condensation

VMC Steam Engine valve case
Removable valve cases with valve free-seats to accommodate steam-tight sealing at all conditions


VMC Steam Engine inlet valve
Variable duration inlet valve events from 83.5% cut-off to zero
VMC Steam Engine gray iron castingsVMC Steam Engine gray iron casting core

Gray iron castings from 3D printed sand molds and cores

VMC Steam Engine frameVMC Steam Engine frame


Customization of our design to meet vertical or horizontal frame configurations, length of stroke, steam conditions, and dead-center loading


VMC Steam Engine poppet valvesVMC Steam engine poppet valvesVMC Steam engine poppet valve diagram

A variety of alternate steam temperature compensating double-beat poppet valve designs as well as low-clearance volume configurations to meet your application requirements are also available.

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