Copper and steam. Yes, again.

JohnNY

So, I'm losing a nice job to a plumber willing to pipe in a Weil-McLain LGB-6 with copper tubing. My insistence that copper is the wrong material to use was met with a "Show me in the manual where it says that." reply from the homeowner and, of course, I cannot produce an official statement. I
called WM and they have decided not to put this into their literature since there are, I'm paraphrasing, already a great deal of copper headers in the field and holding that position would create a great deal of liability for the installers of those boilers. The Tech Support Agent cited "standards and practices" dictate otherwise, of course. I know this is not a unique position to be in, so how do you guys handle this?

Do me a favor, though. Don't tell me "good riddance" or any of that. I wanted this job. It's one of those jobs where a good installer would make a real difference by removing a poorly installed boiler and putting in a good functioning system to the great benefit to the home and the comfort of the family.

Jamie Hall

I sympathize! I lost a few jobs in my professional career which I really wanted for similar reasons.

So -- let me take a rethink on steam vs. copper. What, after all, is the problem with copper? Expansion. Or rather, differential expansion. And I have an idea. Laugh all you like -- particularly you, @JohnNY , since you're forgotten more about plumbing and heating in general and steam in particular than I'll ever know!

What would happen if one did use copper on, say, at two riser drop header job? And then -- at relatively small expense -- put unions on both risers going up and on both the downcoming legs of the risers to the header? The result would be that the two U's (well, upside down U's) of the risers could swing more or less freely on the unions, and would not be able to transmit any expansion from the header to the boiler block. Neither could the equalizer. You could do it with unions on only one of the two risers, too, but if you're going to do it on one, why not both?

On bigger sizes you could go to bolted flanges -- they won't transmit much torque, either.

That wouldn't work with a straight up to the header no drop header arrangement, of course,

The rest of the job could also be in copper, too, provided that one made allowance for expansion somewhat similarly where it was needed.

Comments? @JohnNY ? @Steamhead , @EzzyT ? @Charlie from wmass ? @DanHolohan ? Am I completely bats or only slightly odd?

EdTheHeaterMan

Things happen for a reason. I am sorry you did not get that job, but you have your way of doing things and that is your minimum standard... "No copper" as we all know it should be. and you did not compromise. You can only wait for that customer to call you back in a year or so after the problems develop. Then you can then charge to remove the copper and install the iron pipe correctly. Just hope they use the correct boiler/size and it is something you would install or at least be comfortable working on. You may be able to get it right yet!

Maybe we could all write your potential customer a letter saying: "The sour taste of a poorly completed project lasts much longer than the Sweet taste of the lower Price"

Better luck next time!

JohnNY

When I talk about copper with steam, I'm drawing from many observations worth noting and one frightening experience in particular. I rarely see copper tubing carrying steam in NYC (Manhattan, Brooklyn, etc.) but in New Jersey I see it all the time. There are several installers in my service area who...well, that's just how they do it. I'm not judging. Everyone has to run their own business. Unfortunately, I see a lot of leaking headers as a result. People don't know when their copper steam pipes are leaking because it's not the same as a plumbing leak. There's no puddle. Nothing is wet. Steam often leaks like a gas and vapor gets absorbed into the surrounding air. As any professional installer worth his salt knows, when steam leaks, water is lost, then new, oxygen-rich-and-corrosive makeup water is needed in the boiler. This shortens the life of the boiler considerably. It also increases operating and maintenance costs. The worst case of copper piping on steam I've seen was when I was somewhere in my 20s in a basement of a small multi-family apartment building in NYC. It was a new installation by the oil company. They had just left the building and I was doing some plumbing repairs. As I was watching the shiny new boiler, right before my eyes the feeder had kicked in and the burner cycled back on. Within 90 seconds we showed steam pressure and then suddenly two 2" copper x male adapters pulled apart from their soldered connections. Two sides of a filler piece between cast iron fittings. Steam filled the room instantly. I shut the switch, ran out, called the oil company and they came back and brazed the fittings. I didn't like that solution, but it wasn't my call. It was a scary moment for a young tech in the field and I'll never forget what steam is capable of doing to a copper joint.

SlamDunk

Gosh, when the manufacturer kicks out the only leg you have to stand on, it comes down to price. Price will drown out good sense sometimes. And, The mfr sells more boilers. Short of making it against code to use copper, you got nothing.

JohnNY

SlamDunk said:

Gosh, when the manufacturer kicks out the only leg you have to stand on, it comes down to price. Price will drown out good sense sometimes. And, The mfr sells more boilers. Short of making it against code to use copper, you got nothing.

All true but I can't blame the manufacturer here. Another truth is that there are a whole bunch of copper-steam installations out there in the field that are operating seemingly without a hitch. I guess it comes down to either wanting to rise to the standard or being content to hover beneath it.

Steamhead

@JohnNY , they obviously weren't interested in a quality install- just a rock-bottom price. You can "discuss" this till you're blue in the face and they will always reply that the other guy was cheaper. Sometimes you just gotta walk away.

Also, what size is that header? The manual calls for 4-inch.............................

JohnNY

Steamhead said: The manual calls for 4-inch.............................

They stuck a bushing in the main and reduced the header to 3” because they suck. 

Steamhead

JohnNY said:

Steamhead said: The manual calls for 4-inch.............................

They stuck a bushing in the main and reduced the header to 3” because they suck. 

Proving once again that you can't fix stupid.

EdTheHeaterMan

I'm guessing that picture is the boiler that is going to be replaced. (I can't see John returning to a job completed by others.) And that boiler looks like it should be in good condition. So, if a boiler that should still be in good condition, that was installed with a copper header, needs to be replaced (before its time), and that customer does not have enough sense to select your company, that is his loss.

I still think we need a letter-writing campaign. LOL

EBEBRATT-Ed

And with Viega approving both Mega Press and Propress for LP steam what are you going to do?

jumper

Is it a matter of copper or a cheap job by cutting corners?
Betcha bargain plumber does not follow W-M installation book.

The Steam Whisperer

Looking at your attached picture there is no way an LGB could be installed in that location and meet the manufacturer's requirements for exhaust venting. On Page 7 of the manual, it requires a minimum of 3 feet rise on the vent pipe before the vent turns horizontal. I contacted Weil about this requirement and I have an e-mail on file from them saying "no exceptions" on that 3 foot rise requirement.

Grallert

I love the folded up jacket cover to expose a leaking back section. I assume that's the reason. There I go making assumptions again.

ethicalpaul

JohnNY said:

Steamhead said: The manual calls for 4-inch.............................

They stuck a bushing in the main and reduced the header to 3” because they suck. 

Doesn't this qualify as a "show me in the manual" moment?

And I do blame the manufacturer for not specifying the materials that will result in the best performance for their product.

I would show the customer the relevant page in The Lost Art (pg 90 in Revisited)

Jamie Hall

At considerable risk of being a nuisance -- which would be nothing new, I admit -- may I suggest that it is very important, when making a flat statement that such and such a material can't be used, or even that its use in an application is bad practice, to understand why. As I noted above, the problem with copper in steam piping is not a materials one, but coping with expansion forces. If one is willing, in this specific instance, to say that there is no way to cope with the expansion forces, then it is certainly legitimate to say that copper should never be used. If there is a way to cope, then you have no argument against its use on those grounds.

Reminds me a little of the arguments a couple of centuries ago about materials for building ships. You can't build a ship out of iron. Everyone knows that iron sinks. You have to use wood. Um... really?

Charlie from wmass

Use of copper is not the issue really. It is simply an indicator the installer does not care to do proper work. Most of us never copper contractors could install a boiler with copper and get the expected 20 years out of it. The reason would be attention to the details that lead to copper failure. in the 1930s copper was accepted as okay for steam as long as allowances were made. The biggest one was to increase pipe size one nominal size as compared to iron. This meant 2 1/2" instead of 2" or 4" instead of 3". suddenly the savings disappear though. Poor workmanship, not using brass transition fittings, lack of allowance for expansion, and lack of adherence to the rules lead for an industry wide ban.

EBEBRATT-Ed

I know the ASME Code does not apply to residential boilers in most cases. What about HP steam? Don't think copper would be allowed. There must be a code thingy here somewhere

JohnNY

And how do you feel about Pro-press copper on steam? I think it eliminates the stress issue but I'd look to insulate it very well....at the very least....if I were to ever use it at all.

Charlie from wmass

I think that any gasket that only has a 25-year warranty for water usage should be avoided on steam. I also feel that the ease of ProPress and megapress leads to even less quality of workmanship on installations. I am now seeing 4-in mega press on steam pipe. And it is very seldom the actual materials or installation methods that are creating the problems. It is the choice of pipe sizes the way that the pipes are routed and the total lack of workmanship.having said that most of the threaded iron jobs that I see are put in incorrectly also.

SlamDunk

My hps system at work has a 10" header and five inches of insulation. All welded steel. When it hammers, it rocks my world so I wouldnt want to see it made of copper.

When I worked for a company that manufactured industrial drying equipment and a customer wanted to stock long, lead time parts, I was always faced with the lower cost of knock offs. Why buy knock offs that wont last, may damage equipment and come with no warranty? Because it is half the price. When I lost a sale, the marketing guys would say I didnt pitch it well enough. Maybe. I was field service, not sales. Often , a cheaper price rules the best sales pitch. Sales guys never agreed- they said I sucked at sales.

jumper

Why should copper be a larger size than steel?

Charlie from wmass

jumper said:

Why should copper be a larger size than steel?

From what I read it had to do with velocity of steam as the actual inside diameter of copper piping is slightly smaller than iron and it had to do with thermal conductivity. The copper pipe would cause the steam to condense faster than the iron pipe does.

SteamingatMohawk

One concern is the difference in thermal expansion of copper vs. pipe/fittings (cast iron/carbon steel). I couldn't find a number specific to black iron pipe.

The coefficient of thermal expansion for the three materials are

Copper 0.0000093 in/in-0F
Carbon steel 0.0000065 in/in-0F
Cast iron 0.0000059 in/in-0F

For a 10 ft (120 in) pipe/tube to heat from 60F to 212F (152 degrees), the calculation is:

Coefficient x length x temperature difference

For:

Copper it is 0.0000093 x 120 x 152 = 0.118 or about 1.9 16ths
Carbon steel it is 0.0000065 x 120 x 152 = 0.183 or about 1.3 16ths
Cast iron it is 0.0000059 x 120 x 152 = 0.075 or about 1.2 16ths

That's not a lot of difference in length of the pipe/tube and certainly even less of a difference in length compared to the other materials (if you subtract the steel from the copper, its only .6 16ths or about a 1/32nd of an inch on 10 feet).

All the other issues mentioned above remain, but I don't think linear expansion difference in the piping nearest the boiler is an issue for copper vs steel and remember this calculation was done for a 10 foot length, so anything shorter is that much less.

EBEBRATT-Ed

@SteamingatMohawk

I agree on the short runs on most boilers expansion isn't an issue. It's lak of any flexability in the piping no swing joints, bull head tees, take offs and equalizer not in the right order wrong size pipe etc.

Bet if someone brazed all the joints like refrigeration it would last in most cases.

The guys that do it in copper and pipe it wrong they probably don't clean the pipe and fittings before they solder it anyhow. It just fits their MO.

Like @Charlie from wmass said if piped right it would probably last.

besides, schedule 40 steel on the steam lines will last 100 years or more why put something in that is that good? That's how they think

Robert O'Brien

JohnNY said:

So, I'm losing a nice job to a plumber willing to pipe in a Weil-McLain LGB-6 with copper tubing. My insistence that copper is the wrong material to use was met with a "Show me in the manual where it says that." reply from the homeowner and, of course, I cannot produce an official statement. I
called WM and they have decided not to put this into their literature since there are, I'm paraphrasing, already a great deal of copper headers in the field and holding that position would create a great deal of liability for the installers of those boilers. The Tech Support Agent cited "standards and practices" dictate otherwise, of course. I know this is not a unique position to be in, so how do you guys handle this?

Do me a favor, though. Don't tell me "good riddance" or any of that. I wanted this job. It's one of those jobs where a good installer would make a real difference by removing a poorly installed boiler and putting in a good functioning system to the great benefit to the home and the comfort of the family.

The issue is cost not really the copper vs black?

jumper

>>besides, schedule 40 steel on the steam lines will last 100 years or more why put something in that is that good? That's how they think<<

schedule pipe for no pressure? How about schedule PVC pipe for sewers? Is stronger better?

SteamingatMohawk

My steam system was built in the 1920s. The only copper is near the boiler where the Knuckleheads made changes that worked marginally, as I mentioned in my escapade about connecting both returns below the water line. When I bought the house in 1989 there was a ~40 gallon galvanized tank on the return, which was eliminated 20 years ago when I had to replace the boiler. That's probably when the returns were connected above the water line. Not until a couple of years ago did I eventually get into better balancing the system and discover the error.

EBEBRATT-Ed

This i copied fro the Copper Development Association

As you would expect:

Can Copper Tube Be Used in Steam and Steam Condensate Piping Systems?
Everyone knows that copper tube has a proven history in use in a variety of applications, however a common question is "can I use copper tube in a steam system?" Just like in water systems, copper tube has long been used in both steam and steam condensate piping systems. The key to its successful use in either high- or low-pressure steam systems is in choosing the appropriate joining method for the service.

Let's consider the most commonly used joining techniques, soldering and brazing. And let's relate everything back to Table 4. Pressure-Temperature Ratings of Soldered and Brazed Joints as found in the CDA Copper Tube Handbook . If we look at the ratings for soldered joints we see that there are four alloy designations provided in the first column of Table 4. They are Sn50, Sb5, Alloy E (a proprietary solder containing no lead), and Alloy HB (a proprietary solder containing no lead). In each case the maximum pressure rating from 1/8" through 12" (nominal) or standard tube sizes is 15 psig for saturated steam temperatures.

If we look at the same pressure ratings for saturated steam for joints made using an alloy having a melting temperature above 1100°F, brazing alloys as defined by the American Welding Society, we see that the pressure rating increases to 120 psig for all sizes from 1/8" through 12".

Why the difference? What are these maximum allowable pressures based on? Unlike the pressure ratings shown for services other than steam, these pressure ratings are controlled by service temperature, not pressure.

Temperature and pressure are directly proportional for steam. As the pressure in the system is increased, the temperature increases accordingly. Saturated steam, a condition where steam contains as much water as it can and still be a vapor, at 15 psig has an absolute pressure at sea level of 29.7 psia (pounds per square inch absolute). At this pressure it would have a corresponding temperature of approximately 250°F which is the maximum recommended temperature for soldered joints as shown in Table 4 of the Copper Tube Handbook. Therefore, rather than the allowable pressure of the soldered joints controlling the rating, the allowable temperature is the controlling factor, leading to the rating of 15 psig regardless of the solder alloy used.

Brazing alloys, with a minimum melting temperature of 1100°F, can withstand higher temperature service without a loss of integrity and therefore have a higher maximum temperature limit. In fact, the allowable temperature for brazed joints exceeds that of the copper alloys that it is used to join, therefore the temperature rating of the copper tube and fittings are the controlling factor. Table 3a and Table 3b of the Copper Tube Handbook shows that the ASME Boiler and Pressure Vessel Code limits the use of copper tube and fittings to a maximum service temperatures of 400°F or less. Using a similar analysis as above, the absolute pressure at which saturated steam has a temperature of approximately 400°F is at 120 psig, the maximum pressure allowable for brazed joints for saturated steam service shown in Table 4.

As with any piping system, the pressure rating of the system is controlled by the lowest allowable pressure of the tube, fitting, joint or joining material. For steam systems constructed using copper tube of Types K or L, the maximum allowable pressure at which the system could be designed would be 120 psig. As shown in Tables 3a and 3b of the Copper Tube Handbook, the lowest maximum operating pressure for Type L copper tube is 127 psig (corresponds to 12-inch nominal Type L tube in annealed form). Since this is more than the allowable pressure for the brazed joint, the 120 psig allowable for the joint is the controlling factor, regardless of the fact that smaller diameter tubes have higher allowable pressures. However, to use copper tube and fittings in a steam system at this pressure the joints must be brazed.

As long as these temperature and pressure limits are met, copper tube and fittings can be used in both high- and low-pressure steam systems. The system must still be designed and installed to meet the requirements of all applicable local, state and federal construction and safety codes for steam applications.

Steamhead

Interesting that they don't mention stress from expansion, which is what eventually causes soldered joints to break.

EBEBRATT-Ed

@Steamhead

There the Copper Developement Assn. They have an excellent manual you can download. I am sure they are more than a little biased

delta T

I would also worry about the work hardening properties of Cu. I have never seen copper tubing fail on a steam system, but we don't have too many copper monstrosities where I live. What I did see once though, was a small 1/2" copper tube fail from work hardening.

It was a large 8" pressure reducing valve for a large trailer park. If you are not familiar with larger PRV's, many of them work by using a small pressure reducing valve to operate the diaphragm on a large pressure reducing valve. Its a cool system, watts has some good info their website if you're interested. Well the diaphragm in the small valve had started to go bad, and it was causing a vibration that harmonized with the tubing connecting the pilot valve to the main valve diaphragm. We got called when the vault (this whole assembly was in an underground concrete vault) started spewing water. When we got it pumped out and found the leak, it was like a torn piece of paper. The piece of tubing just ripped apart after the vibrations had made it so brittle that it could no longer withstand the 65 psi or so that it was under.

I wonder if there are installations out there, where copper tubing is being subjected to enough thermal stress over time that work hardening becomes an issue.

ChrisJ

My system has some copper in it above the water line and it used to have more.  From what I've seen there's no issue with straight single runs where at least one end can move.  I have also not observed any kind of corrosion from it either.

A boiler with one riser may be fine but I don't think two would work at least not easily.

Brazing would be best.

All of that said, if a contractor said he wanted to pipe my boiler in copper it would be a red flag. 

gennady

I had a similar situation. Went through all available standards and codes. Could not find anything that forbids copper on the steam. My personal opinion is that soldering is a mechanical joint, and not a good one. The steam operation applies cyclical loads to the joints, which will eventually destroy the joint. I don't feel comfortable installing copper on the steam and would pass on the job with no regrets.

Intplm.

JohnNY said:

When I talk about copper with steam, I'm drawing from many observations worth noting and one frightening experience in particular. I rarely see copper tubing carrying steam in NYC (Manhattan, Brooklyn, etc.) but in New Jersey I see it all the time. There are several installers in my service area who...well, that's just how they do it. I'm not judging. Everyone has to run their own business. Unfortunately, I see a lot of leaking headers as a result. People don't know when their copper steam pipes are leaking because it's not the same as a plumbing leak. There's no puddle. Nothing is wet. Steam often leaks like a gas and vapor gets absorbed into the surrounding air. As any professional installer worth his salt knows, when steam leaks, water is lost, then new, oxygen-rich-and-corrosive makeup water is needed in the boiler. This shortens the life of the boiler considerably. It also increases operating and maintenance costs. The worst case of copper piping on steam I've seen was when I was somewhere in my 20s in a basement of a small multi-family apartment building in NYC. It was a new installation by the oil company. They had just left the building and I was doing some plumbing repairs. As I was watching the shiny new boiler, right before my eyes the feeder had kicked in and the burner cycled back on. Within 90 seconds we showed steam pressure and then suddenly two 2" copper x male adapters pulled apart from their soldered connections. Two sides of a filler piece between cast iron fittings. Steam filled the room instantly. I shut the switch, ran out, called the oil company and they came back and brazed the fittings. I didn't like that solution, but it wasn't my call. It was a scary moment for a young tech in the field and I'll never forget what steam is capable of doing to a copper joint.

@JohnNY This explanation ^^^^^^ is very good. It's a shame you didn't get the job. I know how it feels when you get all geared up and motivated to do a job that is sure to be a big improvement only to find that you lost out to inferior workmanship.
In the future, maybe consider printing out a version of the above explanation, and showing it to the customer? I think it is a very good reflection of what is best for potential customers.

gerry gill

I just looked at a water boiler that is still on a gravity hot water system that has a 3 inch copper header fixing both outlet ports,where as Old Joe, who was my mentor would’ve said, girdled the boiler. The boiler was only installed in 2007 and is now cracked. I have no other choice but to assume it was from stress from the girdled Header.

ethicalpaul

There are other causes of cracking certainly. I wouldn't call it optimal, but it seems strange to me that a cast iron block would find enough stress from a copper header to cause it to crack. I would picture more stress coming to the block from a correctly-piped steel pipe header even with proper swing. Anyone who has disassembled a steel and iron header that's been in place for a few decades knows that it doesn't really provide any "swing". It will provide some flex, but more than copper pipe?? But I don't know much admittedly.