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I am building a house and am interested in using Polybutaline pipe instead of Copper. The people I have talked to are widely divided. They either love it or say that it will leak and to avoid it at all cost. The advantages, I understand are that it can be “pulled” like wire and no joints except at origin and at the fixture are needed and that it doesn’t need to be insulated. Any thoughts appreciated.
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Gail
I believe the pipe you are considering is cross-linked polyethylene,polybutylene is no longer made as far as I know at least up here in Canada its not. I personally plumb with copper on all custom homes. I do use poly on spec. homes because of the cost.The reason I prefer copper is we know it will last at least here it does, there are some areas where copper is not a good choice due to the well water acting on the copper. When I do use poly I use WIRSBO as it has been under long term tests in Europe for close to thirty years.One thing to point out is the installation of poly should be done similiar to copper by using isolation clips so the pipe does not touch wood anywhere as when the pipe expands it can still make noise althougt not as much noise as a shoddy copper installation could make. Hope this helps, good luck on your construction project.
*Polybutylene pipe had its probs in the US where it was often not installed properly which resulted in a class-action lawsuit, so if you are in the US you won't be allowed to use it, though there are still fittings available for repair work, mostly of the compression variety from what i've seen. I have three houses plumbed with PB from before the ban and far fewer problems than my neighbors with copper and galvanized systems. Corrosive water will dissolve CU and deposit stains on your fixtures, as well as wear out the CU pipes, so i avoid it. Plastic can freeze and thaw without needing repair, as mine has several times in extreme weather when even frost-free faucets were biting the dust.PEX (cross-linked polyethylene) is a newer, better plastic material available everywhere, with a variety of fittings available. You need a special tool to attach them, but my supplier lends me the tool when i buy the material there. You can do gentle bends in it (there are radius limitations depending on size of pipe) and often step down a size because of less friction than other types of plumbing systems.
*b WBA At Your Servicesplint, "you can step down a size because of less friction" Is this true ? Do you know of any lab tests done that prove this ? I just did a job last week where a different plumber was using Aquapex by Wirsbo. It was my first exposure. The tubing marked 1/2" was actually 3/8" to 7/16" ID with fittings that were 5/16" to 3/8" ID. This is a lot smaller. I asked the plumber about the difference as far as the flow volume as a comparison to copper and he had no answer but that he would look into it. It looks like a great product that goes in very quickly. He claimed it was very close in cost to copper.
*Plastic pipe (PVC, PEX, etc.) definitely has less friction drop than the same ID of metal pipe, especially used steel pipe. I wouldn't drop a whole size (3/4" to 1/2") going from copper to PEX, no way. But I agree with someone's arguement that in a few years, 1/2 ID PEX will allow the same flow as 3/4" steel. But the better approach would have been to use 1" steel then.Use 3/4" copper or PEX to each room. 1/2" to each fixture. That works. Smaller might work, but not always. -David
*This is from JLC, an article by Thorp Thomas called "Plastic Plumbing Comes of Age":http://www.jlconline.com/jlc/archive/plumbing/plastic_plumbing/index.htmlPros and Cons of PEXPEX tubing comes in all standard nominal sizes (1/8 inch through 2 inches). National plumbing codes mandate certain minimum pipe sizes to each fixture or bathroom group, but they also mandate maximum line pressures in pounds per square inch (psi) and minimum flow rates in gallons per minute (gpm) — after all, it’s the flow at the faucet that really determines whether the customer’s needs are met. In this regard, manifold systems using PEX tubing often give better service than copper systems, because they provide better flow rates. The major difference in flow between equal runs of PEX and copper comes when you add fittings to a copper pipe layout to accommodate corners and bends — each fitting reduces flow and pressure. In calculating required pipe sizes for copper water supply lines, plumbers use tables that account for numbers of joints as well as lengths of run. In terms of flow restriction, each copper elbow adds the equivalent of 10 linear feet to the "developed length" of a run. Piping layouts with fittings necessitate larger diameter pipes to provide the required volume to the fixture. PEX has the same flow rate as copper tubing per equivalent size and length, but because it easily bends around obstacles and snakes through framing cavities, PEX lines generally run all the way from the manifold to the fixture with no joints, and thus less pressure drop or flow reduction.Even the straight joints that are needed to make long straight runs with copper pipe can reduce the pressure and flow in the pipe, if (as often happens) the ends of the pipe are not properly reamed out before each joint is made: Resistance to water flow really occurs at the inside surface of the tube, and turbulence around the rough joints causes significant pressure drops in a straight pipe.and this from "Repiping with Pex" by Garry Gage:http://www.jlconline.com/jlc/archive/plumbing/repiping_pex/index.htmlOnce a route is planned, it’s easy to size piping. After determining the incoming water pressure, a chart in the plumbing code specifically defines how many fixtures can be run off of each size of piping. If I haven’t had to replace the pressure regulators, I always check them to make sure they’re working properly. Typically, water pressure on a water supply system should be regulated at around 65 psi.So there is no hard and fast rule about down-sizing except to add up the fixtures per line, and figure in how many bends; fewer bends = less friction = possibly smaller size. Most of my fixtures are very close to my pressure tank with few bends, so only one line is 3/4" to a bath 30' away. My plumbing supplier is the one who told me about being able to drop a size for short runs, to tell the truth.The rest of the articles are very informative, especially related to your comments about cost. The PEX joints are more expensive, but there are fewer and you pick up savings in labor, especially if any snaking is necessary, and no danger from flame. The two articles explain the pros and con's of the home-run system as opposed to the old-fashioned way, too.
*Polybute = class action suit.
*Splinter: Thanks for the info. I agree with most of the excerpt in your post but not the following: "In terms of flow restriction, each copper elbow adds the equivalent of 10 linear feet to the "developed length" of a run".Fittings definitely add to the pressure drop of a run, sometimes surprisingly so, especially if the run takes a circuitious route. But a tight 90 (like a copper 90 ell) is the equivalent of 30 pipe diameters (30" or 2.5' for 1" pipe, 1.9' for 3/4"). Not 10' unless you are talking about 4" pipe. I've installed a lot of 4" water supply pipe, but never in a residence. Makes me wonder if the article was written by some PEX industry mouthpiece.I think both copper and PEX have their place. In my own house, I installed 900 feet of PEX and 200 feet of copper.An aside: a 45 ell has half the pressure drop as a 90 ell so if you can do an offset with two 45's instead of two 90's, you'll get better flow. -David
*David, thanks for your review. Your comments always lead me happily to more questions. The ten linear feet seemed a lot to me, too, but i think the writer said he was referring to tables, so i guessed the tables might be allowing for less than ideal joinery...?I know that PEX can't be attached directly to a boiler, but what else conditioned your use of copper v. PEX?And yet one more thing i don't follow: if a 45º bend has half the pressure drop of a 90º ell, but you use two 45's, doesn't that count the same?
*Splinter: Maybe the tables could be for very badly done copper 3/4" pipe (ridges from cutting remaining on the inside of the pipe) but it still seems like a lot. An old plumber told me you should ream out the cut pipe till it's smooth enough to put your p@#$%^r in. That's why the tubing cutter has a reamer built into it.My selection of copper versus PEX in my house was not very sophisicated. The radiant floor is PEX till it stubs up. Everything else is copper because I like laying copper pipe and I trust it. Plus I had some tight bends around a structural beams. But I can appreciate the lack of fittings in many pipe runs that PEX would allow. My radiant floor in the garage and the radiant snow-melt sidewalk are also PEX.Yes, if you use two 45's instead of one 90, there would be the same pressure drop but greater cost and labor. I was referring to times that you need to do an offset to either jog around an obstacle (or if you need two fittings to create some weird angle). Then two 45's is better than two 90's because of the lower pressure drop through the fittings and also because you can take often a diagonal path and reduce the amount of straight ("homoerotically-defienct") pipe thereby reducing pressure and materials used. -David
*I see about the 45's--i had a gentle bend in mind instead of an offset. Thanks again.I find i have less blood to wipe on my jeans when i trim the cut ends on the disk sander. About your method for checking for ridges--that 1 1/4" is pretty pricey, isn't it? ;^)
*b WBA At Your Servicesg and dave, kudos to you both for running with this one, thanks. i have more questions, but for now i'm too busy cramming napster downloads. by the way, have you ever used a real pipe reamer ? i don't mean the piece of junk that's attached to the end of a tubing cutter, either. it is a tool made by General that has a metal handle about 4 or 5 inches long with a swiveling cutter (replaceable) on the end. just stick it in the end of the tubing and give it a ream job ! it takes about 5 seconds and works incredibly well. the tool costs about 5 or 10 bucks. i impress plumbers on a regular basis with it. sometimes i think General keeps them a secret.
*Splinter: That's why you hire others - to check the smaller sizes. Speaking of blood on the jeans, what makes the biggest difference for me is having a selection of great scissors. The less I use the razor knife as a pair of scissors, the more I've got left to donote at the blood bank.Tim: I have to admit I usually just use the lousy one on the tubing cutter, although I have a big homping one that fits my Rigid ratcheting die handle. Where I can the General one you use? I had a really tapered one years ago, but it was small - only for 1/2" and smaller, but the small angle of the taper and the 6 or so cutting edges made it smooth and quick. -David
*Sounds great...don't believe i've ever seen one so i'll look harder next time i'm in civilization.
*Gail,I had a house back in Va that had Polybutaline piping & fittings. I had two fittings break due to what was termed "clorine embrittlement". Basically the clorine in the water reacted with the materials in the fittings & the got so brittle that the normal vibrations in the pipes caused the to crack. I was told that this problem was with the fittings & not the pipe but I went on ahead & pulled it all & replaced with copper. As I pulled the piping, I found that I didn't have to cut it up into section for disposal. I simply folded the lengths over & it would snap. Maybe the materials have been changed & Polybutaline doesn't have these problems any more, but I wouldn't use it again.
*As I understand it,polybutlene pipe is no longer available. It has been replaced by "ex", which is supposed to be a different type of plastic.I've worked with both and have no problem with using ex for repairing existing plumbing,especially where using a torch is difficult or dangerous.But In my own home I prefer copper piping!I have read that in certain "applications" ,"plastic" pipes "may" allow Bacterial growth in the lines,but this may be incorrect.
*The spell check on this is goofy!The designation,ex, should read as Pex,also know as polypropelene.
*i as Pex,also know as polypropelene.Not unless you're plumbing with underwear... see post #2.
*in our rural "neck of the woods"PEX is the choice of many. I'm told that well water wreaks havoc on copper. Also although you can buy long rolls of the stuff' alot of plumbers will tell you it's a pain and request 20' "sticks".
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I am building a house and am interested in using Polybutaline pipe instead of Copper. The people I have talked to are widely divided. They either love it or say that it will leak and to avoid it at all cost. The advantages, I understand are that it can be "pulled" like wire and no joints except at origin and at the fixture are needed and that it doesn't need to be insulated. Any thoughts appreciated.