Surface Tension Elements (STE) / Propellant Management Elements (PMD)

Tomahawk Cruise Missile
Designed to fly at extremely low altitudes at high subsonic speeds, Tomahawk® cruise missiles are piloted over an evasive route by several mission tailored guidance systems. The first operational use was in Operation Desert Storm, 1991, with immense success.

VACCO’s Wintec metal mesh surface tension elements are used to separate free gas from liquids. The principle of operation involves the phenomenon that once a material containing fine pores or openings is wetted with a liquid, it will allow free flow of the liquid, but resist flow of a gas.

The liquid forms a film across the pore openings and the gas bubble must break this film in order to pass through. This resistance to gas flow is a function of the size of the opening and the surface tension of the wetting liquid. The smaller the opening and the higher the surface tension, the more pressure is required to force the gas bubble through the material.

Because the VACCO Wintec fine screen material used in filters provides hundreds of thousands very small openings, it is ideal for use in surface tension elements, providing a natural addition to the VACCO Filtration product line.

VACCO’s knowledge of the characteristics of liquid and gas flow through fine wire mesh provides the clear experience factor that makes us a leader in the field of surface tension elements. There are many possible applications for surface tension elements, which include:

Surface Tension Element (STE)
VACCO’s STEs are used in the fuel system on Tomahawk cruise missiles to prevent gas bubbles from entering the engine.