How to properly Purge with caleffi Fill/Purge cart?

Mail4tommo · April 20

The instructions that came with the cart isn't the greatest.. you think for the price it would be a little better.

So how do you properly Purge a system with this? Obviously you put a valve in the system with the hose bibs on either side of the valve..

But do you fill the cart partially? If you have the feed valve open won't it flood the cart? I just want to know how to use this thing right any help would be great thank you guys.

hot_rod · April 20

It depends on how you have purge valve set up. Are you doing a zone by zone, or the whole system at once. You can buy purge valves, Webstone is one brand. Or build your own with a ball valve and two hose valves.

Get a Webstone, they have good purge cocks, better than a boiler drain for pumping into.

Shut off the fill valve

Fill the tank with about 10 gallons of water.

Pump into one valve, purge back into the tank from the other valve/ hose.

If there is a lot o0f air in the system you may need to top off the tank. As air comes out water from the tank replaces it.

You can also add a cleaner to the tank and circulate that for a day, if you have a dirty system.

This graphic shows pumping DI water into a system.

EdTheHeaterMan · April 20

Pretty easy instructions to follow. even has pictures:

Looks like you need to add their three valve fitting to the piping somewhere

hot_rod · April 20

The pump cart is just a tool, there are many ways it can be used and connected.

Mostly they are for filling systems with glycol.

In some cases they get used to circulate a cleaner at high flow rates to scour a system.

Filling solar thermal systems.

Filling and flushing A2WHP loops.

Or purging problematic GEO loop fields.

Mail4tommo · April 20

@hot_rod

@EdTheHeaterMan

I have the the valves and everything installed in the system already. I used it to add cleaner already. I was just unsure of the purging process how much water to put in the cart and how that would all work without overflowing the cart .

EdTheHeaterMan · April 21

If the cart has at least 3/4 of a tank and the pump always has water to draw from, you will never overflow the cart. Between the water already in the system and the water in the cart, as long as the cold water feed valve is closed so nothing is added, it is impossible to overflow the tank. The pump and tank cannot increase the total amount of water in the system including the 3/4-full tank.

The only thing that will happen is that air is removed from the system, which actually causes the water level in the tank to drop, as air from the system enters the tank while water is being pushed into the system.

My concern would be if you have more air in the system than a 3/4 tank of water can replace. In that case, as you remove air from the system, the water level in the tank on the cart could drop below the pump inlet and begin drawing air and reintroducing it back into the system you are trying to purge air from.

GroundUp · April 22

The system doesn't just magically make more fluid. Drain the system to 0 psi and add whatever you need to the cart to purge, and the level will stay the same. You don't want the fill valve open while purging, that's why the purge cart is there.

Mail4tommo · April 27

@EdTheHeaterMan

That's the exact information I needed. I wasn't sure about the fill valve while doing this, what you said make total sense. Thank you very much I appreciate it.

How to properly Purge with caleffi Fill/Purge cart?

Comments

Categories