You want to use a normally open solenoid valve, I like the ASCO 8210G34 or the DEMA O474P.6D. DO NOT! use a DEMA 0414 solenoid valve they don't work very well. I have a trunk line that runs in back of the pumping equipment with a “T” off of the trunk line that supplies water to each pump. At the pump I have a “T” on the high pressure side of the pump with a needle valve and a high pressure check valve to prevent high pressure water from going into the weep system. The trunk line continues to the foam brush system to supply weep water the foam brush system. It’s about as simple as you can get, I very seldom ever have any issues with my weep system. When you mount the temperature sensor you want to mount it on the north side of the building in the shade, it’s best to make a bracket to keep the sensor about 4” to 6” away from the building and don’t mount the sensor in the bay if you have floor heat, you’ll pickup heat from the floor. I’ll try to get some pictures on Saturday.
I install a switch between the Weepmizer and the solenoid valve. I do this to turn off the power to the solenoid valve in the summer months. The weep valve I put a ball valve (yellow handled valve) in front of the solenoid valve so I can turn off the water to the weep system. Just downstream of the solenoid valve I have a "T" just is where I connect air and pump in windshield washer fluid in the winter months when I shut the car wash down. The normally open solenoid valve is the only valve in the weep system. The connection of the weep water to the High pump is just after the Cat 310 pump. The there is a high pressure check valve and a needle valve to adjust the flow. The weep water to the Foam brush is a simple manifold with a low pressure check valve and a needle valve for each bay. I've never had a problem with the soap being diluted by the weep water, the foam brush pressure is higher than the weep water pressure.
