If the orifice of a valve assembly is oversized, what is the likely outcome?

When the orifice of a valve assembly is oversized, it can lead to a phenomenon known as "hunting" or "surging." This occurs because an oversized orifice allows too much fluid to flow too quickly, which can disrupt the stability of the flow within the system. The result is fluctuations in pressure or flow rate, often seen as oscillations that can cause instability in HVAC systems.

In systems where precise control of flow is necessary, an oversized orifice may not effectively regulate the flow rate. The control mechanisms, such as actuators and sensors, may respond to these rapid changes in flow conditions, attempting to compensate and stabilize the system. This constant adjustment leads to hunting or surging, characterized by the system cycling between too high and too low flow rates.

In contrast, an appropriately sized orifice would provide more stable flow control, contributing to the proper operation of the HVAC system. Reduced flow, increased efficiency, and lower pressure are more likely associated with restrictions or undersized components in the system rather than the effects of an oversized orifice.