VALVE n.
above another, which rest upon two corresponding seats when the valve is closed. -- Equilibrium valve. (a) A balance valve. See under Balance. (b) A valve for permitting air, steam, water, etc., to pass into or out of a chamber so as to establish or maintain equal pressure within and without. -- Valve chest (Mach.),…
VICKERS-MAXIM GUN n.
e of a system of ordnance, including machine, quick-fire, coast, and field guns, of all calibers, manufactured by the combined firms of Vickers' Sons of Sheffield and Maxim of Birmingham and elsewhere, England.
VIRTUAL a.
cey. Principle of virtual velocities (Mech.), the law that when several forces are in equilibrium, the algebraic sum of their virtual moments is equal to zero. -- Virtual focus (Opt.), the point from which rays, having been rendered divergent by reflection of refraction, appear to issue; the point at which converging…