Caleffi’s high-flow adjustable thermostatic mixing valves are for radiant heating and hydronic heating systems, as well as domestic water. The adjustable thermostatic and pressure-balanced mixing valve, MixCal 521 series (pictured), is certified low-lead brass, 1/2” to 1”, sweat and NPT union, 3/4 press union. The 5231 series is dezincification-resistant certified low-lead brass, 1” to 2”, sweat and NPT union. Anti-scale materials prevent scaling on internal sliding parts, which reduces jamming caused by lime deposits. An adjustable thermostatic and pressure-balanced mixing valve, 5213 series, is certified low-lead brass, 1/2” to 1”, sweat and NPT union.