Water hammer in return line from Baseboard heating attached to steam boiler

acl10

I have steam in the house and baseboard in the basement that runs from my steam boiler. The pump is on the supply side. I am getting water hammer in the return line of the baseboard when it is on at the same time the steam is on. I put a check valve on the line Everflow 210T034-NL 3/4-Inch Lead Free Brass Swing Check Valve with Female NPT Threaded, 200 PSI WOG & 125 PSI SWP Brass Construction Higher Corrosion Resistance Economical Durable & Easy to Install and it got a little better but it still has water hammer. Should I change it to a ball type check valve like Smith-Cooper International CV30 Series Brass Check Valve, 1/2" NPT Female, Non-Potable Water Use Only?
Should I put another vent on the line after the check valve near the boiler?

acl10

Here you can see pictures of the return line I put in with the swing check valve. I was thinking of changing it to a ball check valve would that work. Also I was going to change the elbow for a tee and put a 4 inch pipe and another vent after the check valve going up. Would that work.

acl10

Would this amount of pressure be enough to hold back the steam if I put it in?

The Smith-Cooper International CV30 series check valve is made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability. Brass can be connected to copper, brass, plastic, aluminum, and welded steel. It has ethylene propylene diene monomer (EPDM) seat and seal, stainless steel spring, spring-loaded poppet, and female National Pipe Taper (NPT) connections on both ends. Female NPT threads connect to male threaded pipes, creating a tighter seal than straight threads. The cracking pressure is 2 pounds per square inch (psi), and the maximum pressure rating is 200 psi.

acl10

If anyone understands this system please comment so I can fix it. thank you

nicholas bonham-carter

While your waiting for the pros to teply, (they are out working), do a search on this site for “hot water loop on steam boiler”, and compare your piping to what is required.
I don’t believe new check valves will solve the problem.—NBC

mikeg2015

The hammer is flash steam. Has nothing to do with the check valve. Check valve just prevents gravity flow backwards through the pump when pump is off.

I’ll have to check the crown boiler manual. But I think they have the return high, supply near bottom of boiler but pump located a few inches lower than the connection point to increase pressure.

Common solution is to have a small 1/2“ bypass line to mix the supply and return a little to prevent flash steam.

Crown boiler has a good diagram in their installation manual. I think it’s the same design as peerless.

mikeg2015

Try valving off the air vent. You normally don’t have air vents on hot water loops on a steam boiler. You normally purge them by valving off the loop and filling with a separate fill connection.

acl10

I never used to have water hammer on the baseboard line it just started. Now it made the connection next to boiler leak because it moved the solder. The supply is on the other side of the boiler, there is no water hammer there. The problem is with the return line that goes back to the boiler. It only hammers when the Baseboard is running at the same time as the steam. If the baseboard runs alone it ok or if the steam is running and the baseboard is off its ok. I think it started when I changed the pump. Maybe this pump pumps slower and the water hits the steam. I put the check valve in so that the water would be isolated from the staem when the baseboard is off. The picture is of the return line.

acl10

I used to have an Armstrong pump and I changed it for a Taco. I dont think thats the problem though.

acl10

Should I put a check valve right near the boiler where the return line meets the boiler

acl10

Will this work near boiler to keep the steam from mixing with the return of the baseboard? The Apollo Valve 61LF-500 series Ball Cone check valve is a lead-free inline valve, and has a soft seat. The valve body and seat are made of bronze for higher resistance to corrosion than brass. Reinforced polytetrafluoroethylene (RPTFE) Ball Cone provides higher chemical resistance. It has female National Pipe Taper (NPT) threads for connecting to male threaded pipes, creating a tighter seal than straight threads. The maximum pressure rating is 400 pounds per square inch (psi), and the maximum steam pressure is 125 psi. The maximum temperature is 350 degrees Fahrenheit. This valve is lead free and complies with California's AB 1953 law for safe drinking water.

acl10

This site recomends a check valve https://www.tlv.com/global/US/steam-theory/waterhammer-condensate-transport-piping.htmlWater hammer caused by backflow of steam from flash tank

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A countermeasure against this is the installation of a check valve to prevent the backflow of steam. However, the effectiveness of this countermeasure is reduced if the location or the type of check valve are incorrect

acl10

Is there no one on this board that understands this setup? I see no one commented.

nicholas bonham-carter

Mike and I replied, and have you followed our advice?—NBC

Jamie Hall

acl10 said:

Is there no one on this board that understands this setup? I see no one commented.

Look again, good buddy

acl10

Closing the valve I tried. I didnt attach a new pipe yet. I am going to try a check valve with a spring near the boiler

acl10

The way its setup its not practical to run a pipe from the return to the feeder line so I need a different solution

Jamie Hall

We may be having a bit of an attention problem here. I haven't commented before, because I'm not exactly sure what I'm seeing. What I think I'm seeing, though, is that at least some of that baseboard piping is above the water line in the boiler. If that is so, then the likelihood is that you are getting the water in that section flashing into steam, since it will be at a lower pressure than the boiling hot water in the boiler. When it flashes, it cools, condenses, collapses -- and hammers; a more severe hammer than that which results from just moving water stopping fast. Which would account for the damaged solder joint; even a poor soldering job will usually hold for a while.

The pipes for the baseboard must not ever run above the water level in the boiler, for starters (there are ways to have them higher, but they involve heat exchangers or using a hot water coil in the boiler).

acl10

I think the boiler is was made by Enerjet. I think they went out of buisness

acl10

two story house with basement. I have 3 small radiators and 10 big radiators. Boiler is Enerjet 262,500 BTU input, 214,000 output and the Square Feet rating is something like 663.
ET-82XW 262.5 214 82.1

AMservices

https://heatinghelp.com/systems-help-center/how-to-run-a-hot-water-zone-off-a-steam-boiler/
This should explain

acl10

On the return side that you are seeing that was the only cutout on that boiler on that side. The house came with this setup.

acl10

My baseboard doesnt have any of those things in the article above. It is just a loop of pipe going out of the left side attached to aquastat and a pump and going into baseboard then returning to the other side of the boiler picture of the supply side with pump

acl10

The return line goes up higher then the water line then drops as you can see in the picture. Should I cut it and make it level. I thought the reason they made it go up like a half square so the water shouldn't flood the boiler when the baseboard is off.

AMservices

If you pipe at the way the diagram shows, with the bypass loop and the flow control valves, That will fix your problems with steam getting into the returns.
For flow control valves you can use simple ball valves. The idea is to Divert the returning water from the heat loop through the bypass to mix with the supply water before entering the pump.
You don't want the water to become hotter then what the pump can handle.
You need the temperature gauge so you can make sure you're adjusting the mix properly.
You should have 2 high limit aquastat's. One to protect the pump from high temperature water ( In other words kill power to the pump if the water gets too hot. Then a second high limit That will shut the burner off if you're not trying to make steam when that zone is calling. If you are trying to make steam, the call from the steam zone needs to bypass that high limit.
You won't need the automatic air vent. After its properly purged no air should be able to get back into the piping unless the waterline is dropped manually or there's leaks in the connections.
You don't need a stainless steel pump. So if you ever have to replace it you can use A cast iron pump that Less than half what the stanless steel pump Costs.

AMservices

I forgot to mention, after you throttle the ball valves, make sure you take the handles off so nobody can easily disrupt things.
The burner high limit should be set at 180°F and the high limit for the pump should be 200°F

acl10

I cant change everything around now. It was like this for years and worked without the hammer. It just started this year for some reason after I changed the pump I used to have an Armstrong that broke and i changed it to Taco. I need a solution within the framework I have already. I has a Honywell RA89a that switches it

acl10

My system doesnt match that sytem at all.

JUGHNE

Did this have any check valves in the system before you changed the pump?

AMservices

How clean is the water?
Maybe the system is surging so bad that it's exposing the heat loop tapping to the steam

acl10

I put this in and it seems to have helped partialy.


The Apollo Valve 61LF-500 series Ball Cone check valve is a lead-free inline valve, and has a soft seat. The valve body and seat are made of bronze for higher resistance to corrosion than brass. Reinforced polytetrafluoroethylene (RPTFE) Ball Cone provides higher chemical resistance. It has female National Pipe Taper (NPT) threads for connecting to male threaded pipes, creating a tighter seal than straight threads. The maximum pressure rating is 400 pounds per square inch (psi), and the maximum steam pressure is 125 psi. The maximum temperature is 350 degrees Fahrenheit. This valve is lead free and complies with California's AB 1953 law for safe drinking water.

acl10

I wasnt able to solder the leak near the boiler because there is water in the boiler and no way to remove it unless I get a pump. {which pump is good for removing boiler water. There are no cutouts on the bottom og=f the boiler. The mean time I put on a pressure coupling

JUGHNE

Did this have check valves before??

AMservices

If you can't drain the water out of your boiler, it's time to call a Professional.
Your on your 3rd pump because it wasn't pipe right to begin with.

acl10

The reason I cant fully drain the boiler is because this boiler never had a drain valve on the bottom. I can only drain until the low water cutoff. Can I pump out the rest and what pump should I use?

acl10

Here is the image of the new check valve I put on. It seems to be working. My theory is that the water in the pipe after the check valve has hot water from the boiler then when the pupmp goes on the cold mixes with that hot and it doesnt directly hit the steam and cause hammer.



You can see the pressure coupling I put on because I coudnt solder. I see that the copper coupling is screwed on to the boiler see picture should I attempt to remove it and put on a brass coupling or would it ruin the threads if I try to remove it?

AMservices

In the 3rd picture down from the top, I see a drain pointing down.
Definitely a bad spot. The drain port is going to act as a dirt pocket and it Could be clogged.
You really need to clean the whole tank. Flashing the low water cut off is important but it's only half the battle.

acl10

I removed the water with a drill pump and I was able to resolder the pipe in

AMservices

How's it working?
Did you flush the boiler clean?

acl10

Yes. all the water is now clean So far ok.

Abracadabra

You used a dresser coupling? Hope that's just temporary.