This technical bulletin includes general information about Penberthy Automatic Injectors plus specific details for individual
unit selection. Used primarily as boiler feed pumps, Penberthy Automatic Injectors are used in numerous other applications for pumping liquids and discharging at high pressure and temperature.


The Injector may be defined as a boiler feeding pump, utilizing the velocity and condensation of a jet of steam from the boiler to lift and force into the same boiler a jet o water many times the weight of the original jet of steam.
Although they are generally considered as boiler feed pumps, injectors are also often used on other applications where hot water under high pressure is desired.

The injector offers definite advantages over mechanically operated pumps when cold water make-up is used to feed boilers. Some of these advantages are:

• Warm water is fed into the boiler without the necessity of preheating the water.
  
  
• It is not dependent upon an outside source of power.
  
  
• Unit is compact, has no mechanically operated parts and requires no foundation or floor space.
  
  
• First cost and maintenance are low.
  
  
• Operating steam is condensed and returned to the boiler resulting in a thermal efficiency of nearly 100%.
  
  
• Dependable in operation.

When steam supply valve is opened, steam passes through steam jet into suction chamber, proceeds through suction jet and out of the overflow. Steam, which attains a velocity of approximately 2500 ft per second as it leaves the steam jet, entrains the air in
suction chamber and creates a vacuum.

The vacuum created in suction chamber begins to draw in water from supply line.

The water is now entrained by the steam and a high velocity mixture of water and steam passes through the suction jet and
out of the overflow.