96 Modern Refrigeration and Air Conditioning Copyright Goodheart-Willcox Co., Inc. flows through the inner tube in one direction. In the outer tube, refrigerant flows in the opposite direction of the water flow. 6.4.2 Liquid Receiver The liquid receiver is a storage tank for liquid refrig- erant located on the high side between the condenser and the liquid line. Occasionally, a liquid receiver is built into the bottom of a condenser, Figure 6-8. During system servicing, refrigerant is often pumped out of various system parts and into the liquid receiver where the refrigerant can be sealed off from the rest of the system. This is called a pump down. Having a liquid receiver makes the quantity of refrig- erant in a system less critical. When a smaller amount of refrigerant is needed, the remaining refrigerant col- lects in the liquid receiver. Most liquid receivers have service valves. A fine copper mesh in the liquid receiver outlet prevents dirt from entering the liquid line. See Figure 6-9. Liquid receivers are usually found on larger HVACR sys- tems that have a significant refrigerant charge. These systems use either low-side float or expansion valve metering devices. Systems with a capillary tube meter- ing device do not use liquid receivers. Blissfield Manufacturing Figure 6-8. Liquid receivers can be small to very large. They allow for greater flexibility in refrigeration volume in the system, which makes charge amount less critical.