Banging steam pipes need help

Pre_war

I am the president of a condo association, its a ten story prewar old glory. Steam heat, old radiators. 112 apartments. Some of the residents complain of banging pipes/radiators when the boiler starts up around is time of year. One can hear the steam rising, then bang bang bang, then quiet. The radiators are a valve on the left top, and a trap on the right bottom. I get this banging on two of my radiators. The super changed my valves and traps. It is not as loud as it was, but still there. Could this be caused because residents in apartments under mine, in the same line have faulty valves or traps?

Rod

Bad Traps

All the traps in a steam system need to be operational/working. A trap is just what it name implys, it traps steam and prevents it entering the return piping. By allowing steam to get into the return line, a bad trap in a steam system will soon destroy the good traps around it.

It's very important that when traps are replaced that ALL traps are inspected and ALL non working traps are replaced at the Same Time!

Another thing that needs to be checked is your steam system's pressure. It shouldn't run over a 2 PSI maximum.  Maintenance people sometimes raise the steam pressure to try to compensate for problems in the system. This just destroys more traps and causes more problems.  They'll tell you something like this is a big building and needs more pressure.

The answer to that is the Empire Sate Building's steam system runs at under 3 PSI so why can 't ours too?   Where are you located? We have some very excellent steam pros who are members of the website who might be able to help you.

- Rod

Pre_war

Steam pipe bangers

We are in Jersey City, Hudson County, New Jersey. Our super is pretty good and put up a notice that people should change their traps etc if they have banging, problem is that people do not want to pay for this and it is an Owner responsibility. The Board could elect to do it as a cost saving measure generally, but getting 112 apartments going in the same direction if rather like herding cats.

nicholas bonham-carter

A common expense

If the boiler were in need of replacement, then it would be a common expense, shared by all owners. As the radiators are part of the system, I think any repairs should be the same sort of common expense, and if the coop bye-laws state otherwise, they have been badly written.

Steam heat is not like gas, or electric heating where modificatioons can be made one part with no effect on the other parts.

I think if you will reduce the pressure in your system, to below 12 ounces, you may find the traps begin to work again. Possibly as rod has said, the pressure was increased to compensate for some deferred maintenance in the system, and the task now is to restore the previous state of operation. Most likely, the fuel cost will be reduced after this is done, sometimes by a third.--NBC

Pre_war

Common banging pipes

Could you explain the difference between PSI (mentioned by previous responder, and the 12 ounces you discuss.



Thanks.

JStar

Steam

Have you had this problem in the past? Did it just start this year? Could be bad traps, or sagging pipes. If it just started his year, odds are that some traps went bad.

nicholas bonham-carter

Pressure descriptions

Psi= pounds per square inch. One pound per square inch is equal to 16 ounces per square inch. Your system will work much better at much less than one pound per square inch.

If your pressure is any higher, the fuel company is providing extra fuel, and making extra charges.

What will you do for the roof replacement-make everyone on the top floor replace his section?--NBC

Pre_war

Strange...

I have 5 radiators. I am on the 6th floor. It is a 3 bedroom, 1900 sq ft. Only 2radiators bang. They only do that when I have the valves turned off. i have all the other valves on the other 3 radiators turned off because otherwise the apt. Is too darn hot. I only open up the living room and bedroom radiator when it is really quite cold. When the valve is open, as they are now, and the steam comes up, as it just has a moment ago, I can hear a gentle gurgle and what sounds like water draining off, and a little occassional cough and then it settles. But not a single solitary BANG!



We have a very big boiler in our boiler room. At any rate it looks big to me, bigger than an elephant. We do not have thermostats in individual apartments. The only way to turn off the heat is with the valve on the radiator. Biggiish building. I emailed the super and asked what PSI our boiler is and he responded: "Well, we have a low pressure boiler that the maximum working pressure and safety valve pressure is 15 psi."

(On the roof issue - of course that it a common expense, and likely you are right the radiator traps because connected like the risers etc, would be common element. )

Pre_war

A couple of years...

No the banging of my two radiators has been going on for years. The super changed both traps and valves in the apartments that requested it. But, although the banging seems a bit less loud, it certainly still occurs, but only when valves on the radiators are off. (See other post in response to NBC.

JStar

Rads

When you turn the valves off, is it when the radiator is already hot?

Pre_war

Well...

This evening i did not consider it cool enough to have heat. So my valves were off and my radiators cold. The steam came up at around 7pm and both radiators did their banging routine. The precise routine is rumble rumble bang bang bang bang, then quiet.



Later, about 30 minutes ago or so, around ten pm, i heard the steam rising up and quickly opened the valves to see if there was banging with valves open., and there was gurgling, draining sound, and a little cough and no bang and the radiators got nice and hot.



It seems very peculiar to me that none of the other radiators suffer from this affliction.

JStar

Rads

Can you check if the rads are pitched towards the trap? Any pictures?

Pre_war

Pic

Here is a photo of the radiator in the bedroom.

Rod

What Pressure is the Boiler now operating?

Ah !  I can now see why you're having problems with your steam system. The radiators are installed upside down!

All kidding aside let's go back and look at steam pressure. Your boiler has a control on it that will shut off when it reaches a maximum set pressure. This should be set to 2 PSI and preferably under that but let;s just be satisfied with a maximum of 2 PSI at the moment.

When the burner on the boiler comes on, it makes steam until the pressure rises to 2 PSI where the control cuts off the burner. When the steam pressure falls to certain point the control will than again tuner the burner on. This cycle continues until the master thermostat that controls temperature is satisfied and this control then turns the burner off.

It maybe on the size of boiler you have (for a large building) that instead of shutting off the burner at 2PSI, it switches the burner to what is know as "low fire" which just turns down the burner rather than completely shutting it off,  In either case it will still maintain a pressure at 2 PSI maximum pressure or less.



The "working pressure" is the maximum pressure that the boiler itself can safely operate and has absolutely nothing to do with the maximum 2 PSI that your steam system should set to operate.  The safety valve is set to exhaust excess pressure at 15 PSI. The boiler itself is tested to 30 PSI but should NEVER run pass the 15 PSI of the safety valve.

Radiator traps are designed to operate a low pressure (under 2PSI) over that and they are quickly destroyed. Let's see if you can find out what the maximum pressure setting is on the pressure controller meaning how high does the pressure go on the pressure gauge before the controller shuts the burner off or, if applicable, changes it to low fire.

- Rod

Pre_war

Continued research regarding upside down radiators

Sorry about the upside down photo, something about the IPAD. I will ask the super for the info and post back.. And thank you for all your help. This is a great website.

nicholas bonham-carter

Banging rads

Why not ask the super also to visit here, and we can ask him any questions directly.

From the picture, I would say you have a vapor system designed to run at 12 ounces maximum, that is .6 psi. It may well run well at 4ounces. In a big building, an extra unneeded ounce of pressure will burn unneeded gas. He should install a vaporstat , and a low pressure gauge both rated for 0-15 ounces, that is .75 psi.

This system when first installed would have been super quiet, even, and efficient; the job of the super is to return it to its original state, if he can with a little help from here.--NBC

Pre_war

Super

I am going to do that. He is an excellent super, best we have had.

Rod

Orifices

As NBC mentioned, two pipe systems like yours when they are properly maintained are very quiet and economical.  Ounce you get the pressure under control . You need to look at the end of the main traps and venting.

You also may want to take a look at the possibility of installing orifices.as they can be used with or in the place of radiator traps. Orifice sizes are based on the size of each individual radiator's  EDR  (There are tables available to help you calculate EDR). Since you probably have a lot of radiators of the same size once you figure out the EDR for that size it just a matter of counting how many orifices you will need. Since orifices meter in just the amount of steam necessary to heat each individual radiator steam usage is kept to a minimum which can result is a large fuel savings.  Attached is an article on orifices which explains them.

- Rod

RDSTEAM

....

Do you guys have a heating company do your work or is it only the super's responsibility? What building are you in? The company i used to work for does a tone of buildings in that area.

RDSTEAM

....

Do you guys have a heating company do your work or is it only the super's responsibility? What building are you in? The company i used to work for does a ton of buildings in that area.

nicholas bonham-carter

Lowering the pressure

You may find that the trap problems go away when the pressure is lowered. As they are now fighting against a pressure for which they were not designed. You won't know what the pressure is at the low ranges required for efficient and quiet operation unles you have a good low-pressure gauge (0-3psi).

You can do a search here for setback and find the general consensus of opinion to be that economy is served best when a constant temperature selection is used. The radiators in your building were surely sized to provide the right level of heat for a given room, so that no overheating should occur.

Do you know what sort of control your boiler uses? There have been great technical improvements by companies such as tekmar in the control of steam systems in large buildings such as yours.

If your individual heat bills are $75 a month, then for an expenditure of $20 each unit, the cost of curing the over-pressure, and the installation of a proper tekmar 279 steam boiler control may be paid from savings in a month or two. You will have to do these repairs sooner or later, so why not now. The traps can be done later when the system has settled down.--NBC