5 ms·

This is my favorite thing I've seen on Hacker News in weeks: immediately made me interested in something I had never thought much about before, gave me the info

by tgb 9y ago

This is my favorite thing I've seen on Hacker News in weeks: immediately made me interested in something I had never thought much about before, gave me the information directly and usefully and got me started on a bunch of related questions. Speaking of which: I had always wondered why more plumbing isn't done with flexible hoses instead of this pipes. Hoses seemed like they'd be way easier to work with. Now my guess is that hoses generally have unnecessary curves no matter what and that this increases the pressure lost. Is that right?

alricb 9y ago
Generally, these days, flexible PEX (cross-linked polyethylene) piping is used for new work in most places. I don't think pressure loss would be much of a problem since the curves in a properly installed system should have a reasonable radius. The reason copper is still used seem to have more to do with inertia and a (sometimes warranted) lack of confidence in new building products.
- tyingq 9y ago
  Well, and this mess: http://www.plumbingfittingsettlement.com/FAQ.aspx http://www.plumbingfittingsettlement.com/FAQ.aspx They've perhaps fixed that by now, but the reputation is there.
kragen 9y ago
Most materials will not last long in water, especially hot water with the various chlorinated organic compounds that result from sterilizing impure water with chlorine. Copper and CPVC are really rather special! Gaviotas had to replace the pipes in all of their aluminum-piping rooftop hot-water heaters with expensive copper when it turned out aluminum could handle chlorine but not the municipal water at their customer sites. All over the US, polybutylene piping turned out to only last about ten or twenty years due to unforeseen issues with chloramine corrosion of the PB pipes and Delrin pipe fittings, but only where they're under stress. And that's why you can't buy polybutylene pipe anywhere in the US since 1995. And it turns out that an unexpected rupture of a water pipe can be very, very expensive indeed. Especially in a wood-framed structure with sheetrock. Especially if nobody's home. So builders are generally very conservative with water pipe materials. Nobody wants to install the next PB disaster. Building supply companies are even more so; the PB lawsuit cost Shell a billion dollars. Garden hoses are usually made from one of two materials: some kind of rubber (buna?) or PVC plasticized with phthalates. With hot water, neither of these will last even the 10 years that a lot of PB piping lasted, and the phthalates will leach out into the water and give it that garden-hose taste. I don't think the curviness of hoses is generally enough to cause a significant pressure loss. As noted in another comment, PEX is sort of flexible and hoselike, and is seeing a substantial amount of use for water piping nowadays.
- userbinator 9y ago
  Interesting fact: lead pipe which was used very early in the days of plumbing (that's where the term comes from: plumbum = lead in Latin) was installed "curvaciously", due to its relative flexibility. It also turns out that when used with hard water, it would develop a calcinous protective layer on the inside over time (and thus the amount of dissolved lead in the water would be less than naive estimates based on completely "fresh" lead pipe), making it relatively corrosion-resistant. Aside: due to the toxicity much of the lead pipe installations no longer exist, so modern pictures of lead pipe installations are exceedingly rare, but for the curious: https://www.nachi.org/forum/f22/lead-drain-supply-2105/ https://www.nachi.org/forum/f22/lead-drain-supply-2105/ The snakelike nature of lead pipe is also immortalised in early cartoons and drawings. You may enjoy reading some early plumbing books: https://archive.org/details/standardpractic00davigoog https://archive.org/details/standardpractic00davigoog
  - deleted 9y ago
    [deleted]
- rsync 9y ago
  "As noted in another comment, PEX is sort of flexible and hoselike, and is seeing a substantial amount of use for water piping nowadays." Yes, PEX is the flexible tubing material you are thinking should exist. PEX and sharkbite fittings are like magic - you can plug together arbitrarily complex water circuits and layouts as simply as building with legos. I personally use copper piping for very long-lived installations and for simple, long runs. However, anything complex at the end of the line (irrigation, pump and well work, filter assemblies, etc.) transitions to PEX and shark bites.
  - 220V_USKettle 9y ago
    I have seen shark bites fail. It is particularly problematic in inaccessible areas (hidden behind drywall). PEX compression fittings with coupled 'sticks' of straight PEX makes runs easier (not having to straighten out the 'coil'). Also, check out the Milwaukee PEX tool. Expensive, but awesome. PS In the first episode of Stranger Things, you can see the hot and cold PEX runs in the kitchen of the diner. Very progressive.
pkaye 9y ago
I think the flexible hoses are very common in newer houses. The labor costs are much lower. It also performs well in cold climates. Apparently the technology started in Germany in the 80s so it is well proven. Matt Risinger, a high end home contractor has some great videos on this technology. https://www.youtube.com/watch?v=KZX0aTvbEzo https://www.youtube.com/watch?v=KZX0aTvbEzo https://www.youtube.com/watch?v=OOeBJ8mDr8Q https://www.youtube.com/watch?v=OOeBJ8mDr8Q
k_sh 9y ago
If you like this kind of stuff, check out 99% Invisible[0]. It's a (very popular) podcast: > 99% Invisible is about all the thought that goes into the things we don’t think about — the unnoticed architecture and design that shape our world. [0]: https://99percentinvisible.org/episodes/ https://99percentinvisible.org/episodes/
JKCalhoun 9y ago
> I had always wondered why more plumbing isn't done with flexible hoses instead of this pipes. My understanding is that flexible hoses were not considered durable. Line your walls with flexible hoses carrying water and your insurance company is going to flip out. Or put another way, flexible hoses didn't meet building codes. Times change though and PEX (a kind of flexible tubing used for plumbing) is now allowed in many (all?) states.

by tgb 9y ago

alricb 9y ago

Generally, these days, flexible PEX (cross-linked polyethylene) piping is used for new work in most places. I don't think pressure loss would be much of a problem since the curves in a properly installed system should have a reasonable radius. The reason copper is still used seem to have more to do with inertia and a (sometimes warranted) lack of confidence in new building products.

tyingq 9y ago
Well, and this mess: http://www.plumbingfittingsettlement.com/FAQ.aspx http://www.plumbingfittingsettlement.com/FAQ.aspx They've perhaps fixed that by now, but the reputation is there.

kragen 9y ago

Most materials will not last long in water, especially hot water with the various chlorinated organic compounds that result from sterilizing impure water with chlorine. Copper and CPVC are really rather special! Gaviotas had to replace the pipes in all of their aluminum-piping rooftop hot-water heaters with expensive copper when it turned out aluminum could handle chlorine but not the municipal water at their customer sites. All over the US, polybutylene piping turned out to only last about ten or twenty years due to unforeseen issues with chloramine corrosion of the PB pipes and Delrin pipe fittings, but only where they're under stress. And that's why you can't buy polybutylene pipe anywhere in the US since 1995. And it turns out that an unexpected rupture of a water pipe can be very, very expensive indeed. Especially in a wood-framed structure with sheetrock. Especially if nobody's home. So builders are generally very conservative with water pipe materials. Nobody wants to install the next PB disaster. Building supply companies are even more so; the PB lawsuit cost Shell a billion dollars. Garden hoses are usually made from one of two materials: some kind of rubber (buna?) or PVC plasticized with phthalates. With hot water, neither of these will last even the 10 years that a lot of PB piping lasted, and the phthalates will leach out into the water and give it that garden-hose taste. I don't think the curviness of hoses is generally enough to cause a significant pressure loss. As noted in another comment, PEX is sort of flexible and hoselike, and is seeing a substantial amount of use for water piping nowadays.

userbinator 9y ago
Interesting fact: lead pipe which was used very early in the days of plumbing (that's where the term comes from: plumbum = lead in Latin) was installed "curvaciously", due to its relative flexibility. It also turns out that when used with hard water, it would develop a calcinous protective layer on the inside over time (and thus the amount of dissolved lead in the water would be less than naive estimates based on completely "fresh" lead pipe), making it relatively corrosion-resistant. Aside: due to the toxicity much of the lead pipe installations no longer exist, so modern pictures of lead pipe installations are exceedingly rare, but for the curious: https://www.nachi.org/forum/f22/lead-drain-supply-2105/ https://www.nachi.org/forum/f22/lead-drain-supply-2105/ The snakelike nature of lead pipe is also immortalised in early cartoons and drawings. You may enjoy reading some early plumbing books: https://archive.org/details/standardpractic00davigoog https://archive.org/details/standardpractic00davigoog
- deleted 9y ago
  [deleted]
rsync 9y ago
"As noted in another comment, PEX is sort of flexible and hoselike, and is seeing a substantial amount of use for water piping nowadays." Yes, PEX is the flexible tubing material you are thinking should exist. PEX and sharkbite fittings are like magic - you can plug together arbitrarily complex water circuits and layouts as simply as building with legos. I personally use copper piping for very long-lived installations and for simple, long runs. However, anything complex at the end of the line (irrigation, pump and well work, filter assemblies, etc.) transitions to PEX and shark bites.
- 220V_USKettle 9y ago
  I have seen shark bites fail. It is particularly problematic in inaccessible areas (hidden behind drywall). PEX compression fittings with coupled 'sticks' of straight PEX makes runs easier (not having to straighten out the 'coil'). Also, check out the Milwaukee PEX tool. Expensive, but awesome. PS In the first episode of Stranger Things, you can see the hot and cold PEX runs in the kitchen of the diner. Very progressive.

pkaye 9y ago

I think the flexible hoses are very common in newer houses. The labor costs are much lower. It also performs well in cold climates. Apparently the technology started in Germany in the 80s so it is well proven. Matt Risinger, a high end home contractor has some great videos on this technology. https://www.youtube.com/watch?v=KZX0aTvbEzo https://www.youtube.com/watch?v=KZX0aTvbEzo https://www.youtube.com/watch?v=OOeBJ8mDr8Q https://www.youtube.com/watch?v=OOeBJ8mDr8Q

k_sh 9y ago

If you like this kind of stuff, check out 99% Invisible[0]. It's a (very popular) podcast: > 99% Invisible is about all the thought that goes into the things we don’t think about — the unnoticed architecture and design that shape our world. [0]: https://99percentinvisible.org/episodes/ https://99percentinvisible.org/episodes/

JKCalhoun 9y ago

> I had always wondered why more plumbing isn't done with flexible hoses instead of this pipes. My understanding is that flexible hoses were not considered durable. Line your walls with flexible hoses carrying water and your insurance company is going to flip out. Or put another way, flexible hoses didn't meet building codes. Times change though and PEX (a kind of flexible tubing used for plumbing) is now allowed in many (all?) states.