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Caleffi 521509A MixCal™ 3-Way Thermostatic Mixing Valve, 3/4" Sweat

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Original price $209.00
Current price $129.56
SKU 521509A
Currently 3 in stock.

Caleffi 521509A MixCal™ 3-Way Thermostatic Mixing Valve, 3/4" Sweat

Stable mixed temperature performance with durable construction for long life

Due to the unique mixing chamber design, MixCal™ produces stable mixed water temperature as inlet temperatures and pressures vary. Scale formation is minimized via sliding surfaces constructed of an anti-scale polymer, thus guarding against seizing or erratic mixed temperatures. Durable peroxidecured EPDM O-ring seals resist wear from common water treatment additives such as chlorine and chloramines.


  • Large mixing chamber and thermostatic cartridge:  Enables precise mixed temperature stability during inlet temperature and pressure variations.
  • Installation flexibility:  ½” to 1” sweat, NPT, Press, PEX crimp and PEX expansion union connections. Temperature gauge and check valves optional.
  • Anti-scale polymer materials:  Inhibits scaling on internal sliding surfaces, assuring stable temperature control and long life.
  • Tamper-proof adjustment setting lock:  Prevents tampering of the mixed water temperature setpoint.
  • Peroxide-cured EPDM seals:  Stands up to treated water, chlorine or chloramines.
  • Precisely manufactured:  Finely machined threads and double O-rings for smooth knob adjustment.



  • Max Working Pressure:  200 psi (14 bar)
  • Setting Temperature Range:  85° - 150°F (30°-65°C)
  • Tolerance:  ±3°F (±2°C)
  • Max. Hot Water Inlet Temp.:  200°F (93°C)
  • Min. Flow For Stable Performance:  1.0 GPM (4 l/min)
  • Flow Rate Working Range:  1.0-14 gpm
  • Material:  DZR low lead brass


  1. ASSE 1017/CSA B125.3, certified by ICC-ES, file PMG-1357.
  2. NSF/ANSI/CAN 372-2011, Drinking Water System Components- Lead Content Reduction of Lead in Drinking Water Act, California Health and Safety Code 116875 S.3874, Reduction of Lead in Drinking Water Act, certified by ICC-ES, file PMG-1360.


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