Buy ac expansion valve1

Water Containment solutions allow for thermal expansion while containing thermally expanded water in the plumbing system. The Watts full line of thermal expansion tanks are considered water containment devices. These products require no installation of discharge lines or drains. Thermal expansion Relief valves discharge thermally expanded water at a pressure setting that is below the setting of the water heater’s temperature and pressure relief valve. Watts offers a variety of water relief solutions that can be installed on the system piping, in a water closet or on an outside faucet. These products must be piped to a suitable drain or discharge location. A thermostatic expansion valve (TXV) is precision device used to meter the flow of liquid refrigerant entering the evaporator at a rate that matches the amount of refrigerant being boiled off in the evaporator, This is it's main purpose but like all the other metering devices it also provides a pressure drop in the system, separating the high pressure side of the system from the low pressure side.  Thus allowing low pressure refrigerant to absorb heat onto it's self. The thermostatic expansion device (TXV)is an orifice for the refrigerant flow. It is a very sophisticated orifice, though. It senses the pressure of the refrigerant coming into the evaporator as well as the temperature of the refrigerant as it leaves the evaporator and then meters the flow of refrigerant into the evaporator to keep it almost perfectly within the engineered specification. The Parker expansion valve needs to see 'a solid liquid head' at all times, in other words the input pipe to it needs to be completely full of liquid, in order for it to be able to meter out the Freon. There is typically a receiver (holding tank) to store excess Freon, or else it is allowed to back up into the condenser in some systems. This is extra freon in the system over and above needed quantity to assure that at all times and operating conditions, there is enough freon to 'present a liquid head' to the Parker PXV.

Thus, seeing as the liquid line is designed to be at all times (running times, anyway) totally full of liquid, a visual reference is relevant. Low level (and some other problems) will show as bubbles or 'flash' in the glass, giving an indication that there is a problem that needs looking at.