Lisebelisoa tse tsoetseng pele tsa ho tjheseletsa tsa arc tse kenelletseng ka har'a lithunya tse peli lia sebetsa. Litsebi li etsa 'mele ea li-valve tsa bolo tse nang le bophara bo boholo tse kopantsoeng ka botlalo ka ho tjheseletsa ka boiketsetso ka nepo e phahameng. Litoche tse peli tse kopantsoeng li tiisa li-seam tsa ho tjheseletsa tse tebileng, tse ts'oanang le tse matla haholo. Sebopeho se kopantsoeng kaofela se fokotsa likotsi tsa ho lutla ka katleho. Li-valve tsena tse tšepahalang tsa bolo li sebelisoa haholo mererong ea khase ea tlhaho, peterole le liphaephe tsa ho futhumatsa, li fana ka litharollo tsa taolo ea mokelikeli tse bolokehileng le tse tšoarellang nako e telele bakeng sa meralo ea motheo ea matla ea lefats'e.