Pressure Controls

• a pressure sensing device used to measure or control the pressure of refrigerant, oil, and water
  
  

Components of Pressure Control

• pressure sensing element
  
  
• bellows
  
  
• diaphragm
  
  
• bourdon tube
  
  
• Connecting Tube
  
  
• capillary tube
  
  
• braided metallic hose
  
  
• small diameter tubing (1/4” O.D.)
  
  
• electric switch
  
  
• adjustment screw
  
  

Applications:

1. used to switch electrical loads, such as compressor motor
   
   
2. used to operate devices directly, such as valves
   
   

Pressure Control types & Switching actions:

1. low pressure control…            closes on a rise of pressure
   
   
2. high pressure control…           opens on a rise in pressure
   
   
3. low ambient control…            closes or a rise in pressure
   
4. oil pressure safety…               closes on a rise in differentia
   
   l pressure