The VP512A1726 is a globe valve controlled by air pressure. A globe valve controls flow depending on the controlling air pressure, from just a trickle to full flow. Called throttling, flow control in this valve is designed for hot water and steam, up to 275 degrees Fahrenheit. The controlling air pressure can be from zero pounds per square inch (psi), to 25 psi.
The VP526A1001 is a two-way flow control valve. It has a cold water inlet, a hot water inlet and a mixed water outlet. Depending on the controlling air pressure, it mixes the amount of hot and cold water delivered to the outlet. The temperature range of the inlets are 35 degrees to 250 degrees Fahrenheit. The controlling air pressure can be anywhere from zero psi to 29 psi.
A three-way valve, the VP519C1006 is designed for controlling the flow of high pressure air. One high pressure air line connects at the bottom and it has two outlets. Depending on the pressure of the low pressure control line, the high pressure air is diverted to either outlet. In this valve, high pressure air can be controlled by low pressure air. The high pressure air can be up to 150 psi. On the low pressure control side, the controlling pressure can be from zero psi to 25 psi.