METHOD OF TWO-SIDED DIRECT-ON ENAMELING OF SHAPED PIPES OF SMALL DIAMETER WITH THREADED ENDS Russian patent published in 1999 - IPC

FIELD: two-sided direct-on enameling. SUBSTANCE: method of two-sided direct-on enameling of shaped pipes of small diameter with threaded ends, mainly, sanitary pipes includes preparation of internal and external surfaces of pipe by picking, application of slip, of direct-on enamel on prepared surfaces by dipping of pipe into slip, runoff of slip excess, its drying, firing of enamel coating and cooling. Prior to preparation of surfaces, screwed on pipe threaded ends are process sleeves for protection of thread from slip, chemical and thermal effect in enameling. After slip runoff, internal surface of pipe is blown through with compressed air. EFFECT: higher quality of enamel coating, prevented deformation and breakage of thread crests and flowing of enamel in thread. 2 cl