Ma Vavulovu Obowola Zingwe

Ma valve a chingwe chobowolera amaletsa madzi kutuluka m'chingwe chobowolera nthawi zambiri ngati chobowoleracho chikagunda ndi gawo lotsika pansi. LANDRILL ikhoza kupereka valavu yotetezeka yotseguka bwino (FOSV), valavu ya Kelly, choletsa kuphulika kwa mkati (IBOP), valavu yowunikira Drop-in, valavu yoyandama.