The tractor air control valve? Stops air from flowing to trailer red air line. Safety switch incase trailer falls off truck all the air will not go out the broken hose and cause tractor spring brakes to lock up due to low air. It can be tested by disconnecting red air line while trailer brakes air released. Air should stop at about 30psi I think.
MV3 valve is specifically a Bendix product. It's basically the (tractor) brake control valve and trailer supply valve in one housing.
Yellow for the tractor brake control valve, red for the trailer supply valve.
Off.
Charge the trailer air brake system and check that the trailer rolls freely then stop and pull out the trailer air supply control also called tractor protection valve control the trailer emergency valve or place it in with the tractor to check that the trailer emergency brakes are on.
oversize for its use
Depends on what kind your talking about. It actually does not control it is a reducing valve by use of diaphragm and spring tension setting in most applications
It does not have a heater control valve.It does not have a heater control valve.
use a PID controller
A thermostatic radiator valve is a valve that is connected to the hot water heating system. It can control the room temperature by regulating the amount of water that goes into the radiator. The valve is able to control this by sensing the temperature of the air.
protection valve maintains air in the tractor brake system in the event of the trailer air lines becoming compromised.for example, if a trailer line is leaking, broken or disconnected
If it's an on-road vehicle manufactured during or after 1975, then yes, it must. It must also have a dual circuit air system, in accordance with FMVSS 121. On a related note, a lot of drivers seem to think the tractor protection valve is the valve which releases the spring brakes on the power unit, and pokes through the dash with a (usually) yellow knob - it is not; that is the brake control valve, which must also be present.
I would use a butterfly valve to set the flow and a pitot tube to measure it. Nexus Valve makes a good one and it is price competetive as well.