Air management in gravity HW systems?
Closed gravity hot water system with a compression tank in the basement.
Anyone try an Airtrol and an air separator on these?
You'd think it'd work as an Airtrol depends on differential temperatures.
Comments
-
I’ve often wondered about using a Discal, with the check valve adapter 5621, then the npt conversion adapter, a 3/8 copper tube up to the tank AirTrol fitting.
I think this could be an excellent air scrubber concept
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
Secondly, i have 2 "risers" (supplies) coming out of the boiler. Can I put an air separator (like a B&G EAS) on each and tie them to a single Airtrol?
If the boiler has an air capture fitting like WM, I'm golden, but if not…?
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
You can also get air seps for vertical piping.
Here is what the assembly looks like. The chrome adapter turns the metric vent thread into 1/4 male NPT. Then use what ever adapter to go to copper, barb hose, pex, etc up to the tank.
I see no reason to not have multiple air purgers?
Which EAS are you considering? The $$ iron body has a vent that has a tire stem thread. You can find adapters for that thread also.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
Thinking about this one. All NPT with a big riser to the tank. Should still work without a pump.(???) I'm concerned about getting air through the little pipe on the other one w/o pumped flow.
IIRC, they make a 2" version which would be even less restrictive.
A large diameter true vertical separator would be ideal.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
I think these type of separators with coalescing media work best on a pumped flow system. I'm not sure they would add much air elimination to what a cast boiler may provide if it has an air elimination tapping.
There is obviously fluid movement in a gravity system to be able to transfer heat energy. Is it 2 fps minimum as in a pumped system?
I'd run this by B&G tech support or the Little Red Schoolhouse for a better answer.
I missed the gravity system in my first post.
https://www.xylem.com/siteassets/brand/bell-amp-gossett/resources/manual/a03852d.pdf
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
I'd doubt it'd be that fast. I agree, a boiler tap is the best bet, but am looking for a fallback position.
Probably will use a WM as it has large supply taps and a boiler air fitting and be done with it.
Thanks, Bob!
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
Edited by me today:
We need pictures please. You have an air management, adding those air eliminators will cause you a great deal of trouble by eliminating the air used to balance the system. You may need a second compression tank if you think you are having circulation problems.
0 -
Closed system @leonz . Why would I need air in the rads? There's air in the compression tank.
At present, there's no air management. Just drain the tank at the start of the season. I'd think an Airtrol with a boiler tap would handle that.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
Speaking as a novice ,
There is air management built into the system with the compression tank.
Is the compression tank fed by a large tapping in the top of the boiler?
Are there orifice plates in the top floor radiator valves? Have either the radiators or the walls behind the radiators been painted recently? I ask this because the painters may have reinstalled the radiators without the orifice plates :^0
How are the radiators piped, bottom to bottom, top on one side with a bottom connection on the opposite bottom side or piped on one side using O-S fittings?
If you install an air eliminator the system will stop working as you would lose the point of pressure change.
The airtrol valve or drain-o-tank valve provides the proper balance of 1/3 air to 2/3 water in the compression tank to maintain the point of no pressure change.
Are O-S fittings used to divert flow to each radiator?
Are there Eureka fittings in the piping?
We/I need Pictures
0 -
I found this Thrush air vent which is slightly different.
0 -
Not sure that you understand the concept of what a flow control valve does @leonz
Take a look at this book.
https://s3.amazonaws.com/s3.supplyhouse.com/product_files/108119-Reference%20Guide.pdf
Read page 9 starting at the top of the second column FLO-CONTROL® VALVES…
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
1 -
That’s a newer version with selectable bypass; the unit I showed required screwdriver and wrench to switch between pumped and gravity circulation mode.
0 -
@leonz Neither of which is applicable to a gravity system.
Seems boiler tap to an Airtrol is the way to go.
@PC7060 is that Thrush valve the equivalent of an Airtrol boiler fitting? If it's a flo-control, that's not what's needed either because there is no pump. See @EdTheHeaterMan 's comment.
None of the other components are really relevant, just looking to get dissolved air to the tank and keep it there.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
Hello PC70,
What are the 2 ports/tappings with the bronze fittings on them?
===========================================================================================
Thank you Ed,
My fluid dynamics experience has been limited to mining equipment including continuous miners using Bell and Gossett pilot operated valves, accumulators, flow dividers, needle valves, pilot operated check valves, gear pumps, vane pumps, open center and closed center control valves, gear driven hydraulic motors and geroller driven hydraulic motors
0 -
Can you post some pictures of the piping from the boiler to the compression tank?
With my pumped hydronic system, The flow from my boiler rises from the steam chest in a pump module. I have a B+G NRF25 circulator, a B+G internal Air Separator piped to the 3/4" Airtrol valve under my Bell+Gossett steel compression tank.
From what I remember of Mr. Holohan's writing and drawings he had a drawing of a riser coming off the steam chest vertically piped directly into the bottom of a compression tank.
0 -
@leonz "From what I remember of Mr. Holohan's writing and drawings he had a drawing of a riser coming off the steam chest vertically piped directly into the bottom of a compression tank".
That is what I'm shooting for. If there's an air separator in the boiler, I just add an Airtrol and I'm done.
As is, hot water circulates to the tank and the tank fills over the season or the air comes out of solution where I don't want it to. Airtrol stops that circulation.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
Thrush valve in picture provides air separation not flow control. The assembly can be configured for either gravity or pumped circulation (see above post).
Does your boiler have a tank? I’d be interested to see the configuration.0 -
You can remove the brass caps to access screws that adjusts a flapper to prevent or allow gravity flow based on system configuration. The one you showed has a lever that does same thing.
0 -
those flo control valves are basically a weighted check valve. Some can be forced open for circulation. The Thrush happens to have a connection for the compression tank, but it is not a substitute for the AirTrol components. The AirTrol fitting in the tank should eliminate you loosing the water or air bubble.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1
Categories
- All Categories
- 86.2K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 52 Biomass
- 422 Carbon Monoxide Awareness
- 90 Chimneys & Flues
- 2K Domestic Hot Water
- 5.4K Gas Heating
- 99 Geothermal
- 156 Indoor-Air Quality
- 3.4K Oil Heating
- 63 Pipe Deterioration
- 912 Plumbing
- 6K Radiant Heating
- 380 Solar
- 14.8K Strictly Steam
- 3.3K Thermostats and Controls
- 53 Water Quality
- 41 Industry Classes
- 47 Job Opportunities
- 17 Recall Announcements