Isihlalo esinokutshintshwa sisihlalo esithambileyo, isihlalo sevalve esiTshintshwayo, xa isihlalo sevalve sonakalisiwe, sisihlalo sevalve kuphela esinokuthi sitshintshwe, kunye nomzimba wevalve unokugcinwa, oko kukuthi ukonga ngakumbi.Umqheba we-aluminiyam awugugi kwaye unesiphumo esihle sokuchasa ukubola, Isihlalo se-EPDM singatshintshwa yi-NBR, PTFE, Khetha ngokwendlela yomthengi.