feed water to input side of air separator to purge?

Joe_30

In "Pumping away", p. 53, the diagram shows the feed water to a boiler with a standard compression tank. The feed water is shown entering the bottom of the B & G IAS inline air separator. Wouldn't you get a better purge ,upon initial filling of the sytem, by feeding the water into the system just before (upstream of) the IAS, so that the water enters the IAS on the left in the usual manner Or is the thing indifferent?

For full effectiveness does this device need 18 inches of straight pipe upstream? See page 49 referring to scoop or orifice devices. So, does it follow to put the feed 18 inches upstream? Thank you. This is a great site. Joe

Gary Fereday

It is a case of turbulance

that the 18" is warrented before a IAS. Large pumps need the same treatment, unless there is a flow pump inlet device employed.
The trick is to get the fluid (water) in a steady mood so to speak and start allowing the entraped air to form up prior to being seperated. In the pump situation it is the same thing, except the smooth continuos flow in to the suction part of the volute is better for the pump. Fittings just before these devices (pumps ,IAS) create turbulance that entraps and helps fluids to keep its air, in micro-bubbles. anyway bigugh