Category Archives for Controlling Refrigerant

HVAC Water valves

Manually operated valves are installed on water circuits associated with refrigeration systems—either on cooling towers or in secondary brine circuits. They are installed for convenience in servicing and for flexibility in operating conditions. These valves make it possible to recircuit, … Continue reading

17. January 2011 by admin
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HVAC Level-Master Control Oil and halocarbon systems

With halocarbon systems (Refrigerants 12, 22, 502, etc.) the oil and refrigerant are miscible (capable of being mixed) under certain conditions. Oil is quite soluble in liquid Refrigerant 12 and partially so in liquid Refrigerant 22 and 502. For example, … Continue reading

17. January 2011 by admin
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HVAC Level-Master Control Oil and ammonia systems

For all practical purposes, liquid ammonia and oil are immiscible (not capable of being mixed). Since the density of oil is greater than that of ammonia, it will fall to the bottom of any vessel containing such a mixture if … Continue reading

17. January 2011 by admin
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HVAC Level-Master Control Oil return

All reciprocating compressors will allow some oil to pass into the discharge line along with the discharge gas. Mechanical oil separators are used extensively. However, they are never completely effective. The untrapped oil passes through the condenser, liquid line, expansion … Continue reading

17. January 2011 by admin
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HVAC Level-Master Control Installation

The level-master control is applicable to any system that has been specifically designed for flooded operation. The valve is usually connected to feed into the surge drum above the liquid-level. It can feed into the liquid leg or coil header. … Continue reading

17. January 2011 by admin
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HVAC Level-Master Control

The level-master control is a positive liquid-level-control device suitable for application to all flooded evaporators (see Fig. 11-45). The level-master control is a standard thermostatic-expansion valve with a level-master element. The combination provides a simple, economical, and highly effective liquid-level … Continue reading

17. January 2011 by admin
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Level Control Valves Float valve

A hollow float is sometimes used to control the level of refrigerant (see Fig. 11-43). The float is fastened to a lever arm. The arm is pivoted at a given point and connected to a needle that seats at the … Continue reading

17. January 2011 by admin
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Level Control Valves Capillary tubes

Capillary tubes are used to control pressure and temperature in a refrigeration unit. They are most commonly used in domestic refrigeration, milk coolers, ice-cream cabinets, and smaller units. Commercial refrigeration units use other devices. The capillary tube consists of a … Continue reading

17. January 2011 by admin
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Discharge-Bypass Valves Hot Gas

Hot gas may be required for other systems functions besides bypass capacity control. Hot gas may be needed for defrost and head pressure control. Normally, these functions will not interfere with each other. However, compressor cycling on low suction pressure … Continue reading

17. January 2011 by admin
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Discharge-Bypass Valves Testing and Operating Pressures

Excessive leak testing or operating pressures may damage these valves and reduce the life of the operating members. Since a high-side test pressure differential of approximately 350 psi or higher will force the DBV open, the maximum allowable test pressure … Continue reading

17. January 2011 by admin
Categories: Controlling Refrigerant | Tags: | Leave a comment

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