Lapped Spool and Sleeve Assembly
The Numatics lapped spool and floating sleeve assembly is a matched set, machined from stainless steel to millionths of an inch precision. It’s patented, balanced construction relies on an air bearing principle, eliminating troublesome dynamic o-ring seals. The sleeve remains stationary in the valve housing, floating on six static seals. The sliding spool is sealed simply by virtue of the close finish tolerances.
With the spool floating on a film of air molecules, there is no metal-to-metal contact. Heat-treating of spools and sleeves gives a hardness necessary to combat pipe scale and other air line contaminants. The spool is balancedwith respect to air pressure, and offers extreme versatility of valve application. It supplies true multipurpose construction. The floating sleeve insures freedom from any mechanical distortion imposed on the valve body. Lubricated or properly filtered dry air will insure longer life; however, the spool and sleeve’s unique design, inherent resistance to contaminants and sticking, will provide years and years of troublefree service, exceeding industrial standards of design and performance.
All these factors give the Numatics Spool and Sleeve a reliability and long service life which have been field proven in maintenance-free operation, typically outlasting the life of the machine on which it was installed.