Air in Recirculating Water System

Assume the bleed points are air release valves.

With water running down or level the air might not be at the highest point.

Suggest air traps on the way down, where the air can be removed from the main flow and released.

On long pipelines is always better to include air relieve valves on rising mains as well to remove any air.

Assuming this is most likely a heating system you need to turn up the water temp to its max setting, and then turn the pump off; after it has got to the highest temp, and then bleed the air out. Water contains disolved gasses that will be released faster when the water is heated. The reason for turning off the pump before bleeding off the air is so as not recirculate the air back into the lower part of the system. If you have a contiuing problem then you may well have a leak. This does not mean you will have vissible water but when the system cools down particularly in the cold of winter the system can draw in air from a joint or compression fitting as a partial vacuum is formed due to the water shrinking in volume as is cools down. Air is easily sucked in but water may not show. Check all joints and if radiators are in use their bleed valves.

Besides manual bleed valves there are air release valves

http://www.valmatic.com/airrelease.jsp

http://www.metexcorporation.com/Hayward/hayward_true_union_air_release_valve.htm

Air degausing valves

http://www.plastomatic.com/venting-valves.html

Siphon Tanks:

http://extension.missouri.edu/explore/envqual/wq0316.htm

Steam traps:

http://www.nicholsonsteamtrap.com/

Spirotherem Air eliminators

http://www.houseneeds.com/shop/HeatingProducts/HydronicHeating/AirVents/spiroventbuypage.asp

, techno.

Sweet!

Mark

To Mark

Thanks

From Mark

We call them air separators, but I like the term swirl pot -- a bit more descriptive.

We have had luck in modifying the pipe where it makes a turn from horizontal to downward by Teeing the line with a length of pipe upward and putting an automatic vent on the upward dead ended Tee, it does a good job of trapping air to get rid of it.

Depending on factors such as everything. System application, open or closed loop, operating temp., supply and return pressures, fresh or brine or glycol based or even DI or RO....etc... Your application could lend itself to draw a vacuum on the resevour. This would serve to 'out-gas' the water; Or, add a column too high that vacuum could draw up the water to the vacuum pump. This would work if the system is closed loop and has some type of sealable resevoir with a void space above the water line. Or if it is the oxygen in the air you want out and leave the rest......Buy a fish! lol

Sorry folks; I missed a "not" between could & draw. 4th last sentence. Keep in mind the height of the column would be served on ambient pressure loops.