English to Lithuanian Tech/Engineering Mechanics / Mech Engineering GLOBE VALVES

Prior to lapping the disc of the globe valves may require refinishing.
When surface damage is minor, the seats may be repaired by a lapping operation by placing a small quantity of lapping compound between the seat and the disc surfaces.
It is important that not too much pressure be applied to the disc and seat.
With the lapping compound in place between the matching surface, the disc should be reciprocally rotated, the strokes should be
light and the disc should be lifted frequently and turned to a new position, circularly around the valve body, so the lapping will
take place over a new area.
Continue lapping until all defects are removed, and then final finish with a fine compound.

reciprocally rotated - priešinga kryptimi ar pirmyn-atgal?