Olu hlobo lwecebo lokucoca ulwelo lusetyenziswa kwinkqubo yokubonisa ubushushu kumanzi acocekileyo. Isihluzi sinokucoca ukungcola kwesinyithi, ukungcola kweerabha okanye olunye ungcoliseko, kwaye ugcine itanki licocekile. Esi sihluzo sinokufakwa kumphezulu wekhava ngqo okanye sifakwe ngombhobho. Inesikhombisi kunye nokudlula kwepasive. Xa ukungcola kuqokeleleka kwisixhobo sokucoca ulwelo okanye iqondo lobushushu lenkqubo liphantsi kakhulu, kwaye uxinzelelo lokungena kweoyile lufikelela kwi-0.35Mpa, isalathiso siya kunika imiqondiso ebonisa ukuba isihluzi kufuneka sicocwe, sitshintshe okanye sinyuse ubushushu. Ukuba akukho nkonzo yenziwe kwaye uxinzelelo lufikelela kwi-0.4mpa, ivelufa yokudlula iya kuvulwa. Isixhobo sokucoca ulwelo senziwe ngefayibha yeglasi; ke inokuchaneka kokuhluza okuphezulu, ilahleko yoxinzelelo lokuqala, umthamo wokubamba ubumdaka njalo njalo. Hluza irediyo 0 3, 5, 10, 20> 200, ukucoca ubuchule n> 99.5%, kwaye ulingane umgangatho we-ISO.