Anti-Gravity Loops Meaning

[cookie85]

Can any commercial plumber please help me out and answer the following question for me?

What is an anti-gravity loop and what is its purpose? We have a tank fed pressurization unit, with a cold feed to the heating flow header. As the cold feed enters the flow header, the pipework sets up about a foot, and then drops back down into the header. On some systems i have seen the p/w will rise to the highest point in the boilerhouse and then drops back down to low level.

Ive noticed the majority of the anti-gravity loops have an automatic air vent on the horizontal pipework at the higest point.

What are there purpose as its a tank fed heating system. And is pressurizied through the pressurization unit?

Any help would be appreciated.

[johnb]

hi cookie anti gravity loops are just that. they prevent hot water gravitating upwards when no pump is on they should have a vent as good practice , I'm not sure what you mean by pressurization unit , all the best john