________ use many types of pressure regulating valves. Examples include evaporator pressure regulators, two-temperature valves, and case pressure controls.

• A. Residential air conditioning
• B. Commercial refrigeration systems
• C. Industrial steam systems
• D. Automotive air conditioning

Answer: (B)

Pressure regulation in commercial refrigeration systems allows precise control across multiple zones. When several evaporators or display cases operate at different temperatures, keeping the refrigerant pressure correct in each area is essential for stable temperatures and efficient operation. An evaporator pressure regulator sets the evaporator’s suction pressure so the coil stays within the desired temperature range and refrigerant flow responds appropriately as load changes. A two-temperature valve provides separate control for two temperatures in the same system, letting one branch maintain a different evaporating pressure than another. Case pressure controls manage the pressure inside each cabinet or display case, affecting product temperature, humidity, and door sealing. This mix of devices is typical of commercial refrigeration because it handles multiple zones with independent pressure needs, unlike residential, automotive, or industrial steam systems which use different pressure-control schemes.