Mavharuvhu etsono anopa yakavimbika kuyerera kwekutonga kwehuwandu hwemashandisirwo uchishandisa akasiyana-siyana edzinde magadzirirwo, kuyerera mapatani, zvinhu, uye magumo ekubatanidza mumagadzirirwo akadai senge integral-bonnet uye union-bonnet.Metering mavharuvhu anopa kugona kuita zvigadziriso zvakanaka kunyatso kudzora sisitimu inoyerera mune yakaderera- kana yakakwirira-kumanikidza, uye yakaderera-, yepakati-, kana yakakwirira-kuyerera zvikumbiro.