Harwil Flow Switch Q12DSCSLA

Flow Switch, Harwil, 1/2" MPT, Factory Set For LA Spas, 3 pin MTA connector, two wires.
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Harwil Flow Switch Q12DSCSLA
#1 Flow Switch
Since the mid 1980's the Harwil Q-12 flow switch has been used by some of the largest companies in the Pool & Spa and fluid control industries. The Q-12 has several factory adjustable parameters that provide the flexibility to meet the requirements of almost any application. The Q-12 verifies fluid flow, typically in conjunction with another device. For example most of swimming pool salt chlorine generators use the Q-12 to verify sufficient flow before the generator is energized. In a spa or hot tub the Q-12 ensures sufficient flow to prevent the water heater from a meltdown. In a chiller the Q-12 prevents the system from freezing. At home the Q-12 turns on the water disinfection system when someone is getting a glass of water.
Additional Information


  • 1 Amp, (2) 3/4" barb fittings x 1/2"FPT housing
  • Flow range is 0.7 - 590 GPM
  • Factory set for LA Spas
  • Max. flow may be five times normal flow
  • Very low pressure drop – typically less than 1.0 psig at normal flow rate
  • Power the driving coil of small ice cube relays as well as some 30A power relays.
  • Switches 5VDC to 240VAC
Alternate Part Numbers
  • Q-12DS-C2/LASPAS
  • W/TEE
  • &
  • CONNECTOR (Harwil)