Astme A453 kalasi 660 ndi lingaliro lazinthu zamitundu, ma bolts, mtedza ndi zomangira zina, zomwe amafuna kuti mugwiritse ntchito kutentha kwambiri. ASME A453 TISONI 660 imawerengedwa mu kalasi ya katundu ya anthu 4 kukhala a, B, C & D, aliyense wopangidwa ndi chotupa chosiyana komanso chopondera. Magetsi 660 amagwiritsidwa ntchito poyendetsa boloni, zombo zokakamira, mapaipi, cholinga chake kutentha kwambiri. Astme A4533 GUDA 660 ndi yofanana ndi Astherm B638 ndi dambo wa 660 ndi shale.