Answer
Jan 24, 2022 - 08:31 AM
The 3 way will vent in the off position to be used as a on/off, to vent the output line when turned off to relieve pressure, and can be used for air only. The 2-way will not vent in the off position, and can be used to turn on and off a water source. To identify, you would have to look at the stem o-rings. The stems will have 3 machined grooves for o-rings to be placed. For the 3-way, 7160, the stem would have o-rings on the groove at the tip, and the groove closest to it the head of the stem. For the 2-way, 7163, the stem would have the o-ring at the tip, and then at the next position up, leaving the groove empty nearest the head of the stem. I have attached images of the two stems and labeled them with the part numbers of the valves they belong to.
