IValve yeBrass Straineryenziwe ngobhedu olubunjiweyo, olukwabizwa ngokuba ivelufa yokucoca ubhedu, eyenzelwe ukuhluza ukungcola kwinkqubo yokulawula ulwelo, ulwelo luqukuqela kwicala elinye kwaye lokucoca nge-s/s isikrini sokucoca ivalve, esetyenziswa ngokubanzi kwimibhobho, ukumpompa, kunye nemibhobho.