Business History Books » Business Consulting » Copper Pipe – Type "L" or Type "M" ???
Copper Pipe – Type "L" or Type "M" ???
Question:
Can anyone tell me why and where I would use each of these Types of copper piping? TIA
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> Can anyone tell me why and where I would use each of these Types of > copper piping? > TIA
Try here: http://www.copper.org/tubehdbk/selecting-tube.html — Robert Allison Georgetown, TX
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>Can anyone tell me why and where I would use each of these Types of >copper piping? >TIA
Type "L" underground Type "K" under driveways or slabs Type "M" above ground
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> Can anyone tell me why and where I would use each of these Types of > copper piping?
Type M is typical in hydronic systems, i.e. hot water baseboard. Type L is typically used for potable water systems. IIRC, M is rated for 100psi, and L 150psi.
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>>Can anyone tell me why and where I would use each of these Types of >copper piping? >TIA >Type L is heavier walled than type M.
There are three wall thicknesses generally available in copper water piping. They are Type-K, Type-L, and Type-M. Generally, Type-K is the heaviest-wall thickness. There is also a thinner-walled product called DWV that is used for drainage applications. It is a good product indeed and under-utilized. Pressure ratings for tubing depend on the wall thickness of the tubing and the type of tubing (hard-drawn or annealed) Depending on the type of water you have in the area (scaling or corrosive) you may want to allow for more wall thickness. Where I work, we do not allow the use of Type-M and require the use of Type-K on all recirculated hot water systems.
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<SNIP good advice about Types K,L,M> > There is also a thinner-walled product called DWV that is used for > drainage applications. It is a good product indeed and under-utilized.
Our experience with copper DWV has been abysmal, on both municipal and well-supplied water. When first introduced, copper DWV was touted as having virtually unlimited life. In practice, the life-span has been more like 35 years. The worst corrosion occurs along sections where soap scum accumulates (sink drains) and where it is intermittently wet (closet wastes). On numerous occasions I’ve had to tear out entire systems where the waste piping was reduced to paper thin remnants. Jim
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– Hide quoted text — Show quoted text ->>Can anyone tell me why and where I would use each of these Types of >>copper piping? >>TIA >Type L is heavier walled than type M. > There are three wall thicknesses generally available in copper water > piping. They are Type-K, Type-L, and Type-M. Generally, Type-K is the > heaviest-wall thickness. > There is also a thinner-walled product called DWV that is used for > drainage applications. It is a good product indeed and under-utilized. > Pressure ratings for tubing depend on the wall thickness of the tubing > and the type of tubing (hard-drawn or annealed) > Depending on the type of water you have in the area (scaling or > corrosive) you may want to allow for more wall thickness. > Where I work, we do not allow the use of Type-M and require the use of > Type-K on all recirculated hot water systems.
Up here in Vancouver we are experiencing many failures of copper piping systems within 20 years and in some cases the systems will fail in 10 years due to pinhole corrosion failures. Our water is from a protected watershed/reservoir which is very soft (low mineralization) and aggressively treated with ozone, chlorine, CO2 and other additives. Our water is also saturated with oxygen and CO2 due to it being an atmospheric source. The bottom line is that with aggressive waters and current water treatment, copper of any thickness is just not standing up to localized corrosive attack such as pinholing and crevice corrosion, especially in recirculated hot water systems. Some things that the copper industry does not want people to know about. BTW the replacement industry is Big Business 
Check out my web page if you want to know more. — Duane M. Tilden PE Crown Mechanical Consulting Web: http://ca.geocities.com/duanetilden/Copper/Copper1.htm
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hey all, can some one,pro’s or diy’s help me with material selection? i plan to run water and electrical to my garage,and would like to find out what materials to use,depths to bury…etc. i live near pittsburgh and plan to park a vehicle over top and want to depth and spacing of the lines to be right.. thanks so much
– Hide quoted text — Show quoted text -> Can anyone tell me why and where I would use each of these Types of > copper piping? > Type M is typical in hydronic systems, i.e. hot water baseboard. > Type L is typically used for potable water systems. > IIRC, M is rated for 100psi, and L 150psi.
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stupid me…wife was gabbing at me. i’ll post a new one
– Hide quoted text — Show quoted text -> hey all, can some one,pro’s or diy’s help me with material selection? i plan > to run water and electrical to my garage,and would like to find out what > materials to use,depths to bury…etc. i live near pittsburgh and plan to > park a vehicle over top and want to depth and spacing of the lines to be > right.. thanks so much > > Can anyone tell me why and where I would use each of these Types of > > copper piping? > Type M is typical in hydronic systems, i.e. hot water baseboard. > Type L is typically used for potable water systems. > IIRC, M is rated for 100psi, and L 150psi.
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– Hide quoted text — Show quoted text ->>Can anyone tell me why and where I would use each of these Types of >>copper piping? >>TIA >Type L is heavier walled than type M. > There are three wall thicknesses generally available in copper water > piping. They are Type-K, Type-L, and Type-M. Generally, Type-K is the > heaviest-wall thickness. > There is also a thinner-walled product called DWV that is used for > drainage applications. It is a good product indeed and under-utilized. > Pressure ratings for tubing depend on the wall thickness of the tubing > and the type of tubing (hard-drawn or annealed) > Depending on the type of water you have in the area (scaling or > corrosive) you may want to allow for more wall thickness. > Where I work, we do not allow the use of Type-M and require the use of > Type-K on all recirculated hot water systems.
I suggest PEX PVC and CPVC in that order because none of those have the problems that copper does with various water quality. Gary Quality Water Asscoiates
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– Hide quoted text — Show quoted text -> >>Can anyone tell me why and where I would use each of these Types of > >>copper piping? > >>TIA > >Type L is heavier walled than type M. > There are three wall thicknesses generally available in copper water > piping. They are Type-K, Type-L, and Type-M. Generally, Type-K is the > heaviest-wall thickness. > There is also a thinner-walled product called DWV that is used for > drainage applications. It is a good product indeed and under-utilized. > Pressure ratings for tubing depend on the wall thickness of the tubing > and the type of tubing (hard-drawn or annealed) > Depending on the type of water you have in the area (scaling or > corrosive) you may want to allow for more wall thickness. > Where I work, we do not allow the use of Type-M and require the use of > Type-K on all recirculated hot water systems. > I suggest PEX PVC and CPVC in that order because none of those have the > problems that copper does with various water quality. > Gary > Quality Water Asscoiates
Hi Gary, Just as a point, CPVC is rated for both hot and cold water applications while PVC is suitable only for cold (for this reason I tend not to specify PVC). In all cases they need to be installed in accordance to manufacturer’s recommendations. Note that CPVC will expand considerably when exposed to hot water, and proper allowance for expansion is required in these installations. Other than that I recommend PEx, CPVC and also lined ductile iron for those larger commercial installations. Of course, in the commercial/institutional and multi-residential/occupancy groups we run into firestopping issues related to the selected piping material passing through fire separations. — Duane M. Tilden PE Crown Mechanical Consulting Web: http://ca.geocities.com/duanetilden/Copper/Copper1.htm – Hide quoted text — Show quoted text –
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– Hide quoted text — Show quoted text -> >>Can anyone tell me why and where I would use each of these Types of > >>copper piping? > >>TIA > >Type L is heavier walled than type M. > There are three wall thicknesses generally available in copper water > piping. They are Type-K, Type-L, and Type-M. Generally, Type-K is the > heaviest-wall thickness. > There is also a thinner-walled product called DWV that is used for > drainage applications. It is a good product indeed and under-utilized. > Pressure ratings for tubing depend on the wall thickness of the tubing > and the type of tubing (hard-drawn or annealed) > Depending on the type of water you have in the area (scaling or > corrosive) you may want to allow for more wall thickness. > Where I work, we do not allow the use of Type-M and require the use of > Type-K on all recirculated hot water systems. > Up here in Vancouver we are experiencing many failures of copper piping > systems within 20 years and in some cases the systems will fail in 10 years > due to pinhole corrosion failures. Our water is from a protected > watershed/reservoir which is very soft (low mineralization) and aggressively > treated with ozone, chlorine, CO2 and other additives. Our water is also > saturated with oxygen and CO2 due to it being an atmospheric source.
Correct about causes of corrosion and I notice there’s no mention of ion exchange softening. As there shouldn’t be. Additional causes are electrical current flow (dissimilar metals and/or electrical system gorunding problems) and bacteria in the water colonizing the tubing. > The bottom line is that with aggressive waters and current water treatment, > copper of any thickness is just not standing up to localized corrosive > attack such as pinholing and crevice corrosion, especially in recircul ated > hot water systems.
"current water treatment" meaning the water company treatment which does not include ion exchange water softening, not water treatment done by their customer. > Some things that the copper industry does not want people to know about. > BTW the replacement industry is Big Business
They and those sold on copper being ‘the best’ material, including codes personel and others. > Check out my web page if you want to know more. > — > Duane M. Tilden PE > Crown Mechanical Consulting > Web: http://ca.geocities.com/duanetilden/Copper/Copper1.htm
I don’t have a web page……. but the web is full of ‘em. Many support either side of any issue, kinda like doctors, lawyers and politicians. There’s some POE/POU water treatment sites too. Gary Quality Water Associates
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– Hide quoted text — Show quoted text -> Up here in Vancouver we are experiencing many failures of copper > piping > systems within 20 years and in some cases the systems will fail in 10 > years > due to pinhole corrosion failures. Our water is from a protected > watershed/reservoir which is very soft (low mineralization) and > aggressively > treated with ozone, chlorine, CO2 and other additives. Our water is > also > saturated with oxygen and CO2 due to it being an atmospheric source. > Correct about causes of corrosion and I notice there’s no mention of ion > exchange softening. As there shouldn’t be. Additional causes are > electrical current flow (dissimilar metals and/or electrical system > gorunding problems) and bacteria in the water colonizing the tubing.
Sorry, I forgot soldering flux, it also causes corrosion. > Gary > Quality Water Associates
Gary Quality Water Associates
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– Hide quoted text — Show quoted text – <snip for brevity> > Up here in Vancouver we are experiencing many failures of copper piping > systems within 20 years and in some cases the systems will fail in 10 years > due to pinhole corrosion failures. Our water is from a protected > watershed/reservoir which is very soft (low mineralization) and aggressively > treated with ozone, chlorine, CO2 and other additives. Our water is also > saturated with oxygen and CO2 due to it being an atmospheric source. > Correct about causes of corrosion and I notice there’s no mention of ion > exchange softening. As there shouldn’t be.
No mention of softening because as you would surmise from the chemistry of the water in question softening treatment is not required. However, there are other issues such as micro-filtration, ozonation and UV sterilization as well as some form of mineral additions which are being sold as building water treatment options. In some cases there are water treatment solutions (mineral additions and activated carbon filters) which are being sold that have claimed will stop copper corrosion. Buffering may reduce copper solubility and the formation of copper chloride which stains fixtures and turns white hair green, however there is no evidence that they stop pitting, crevice or stress related piping failures. (Nobody wants to talk about sodium silicate or waterglass!?) Most people believe that pH is the only necessary indicator of corrosion, and do not understand about the Langeliers Index and/or electro- chemical corrosion processes. Also, I would like to note that in my opinion the pH does not properly account for residual chlorine or other ions introduced or present in the water. Chlorine, dissolved oxygen and carbon dioxide are proven destabilizers of the protective oxide layer which forms on the inside of copper piping and accelerate electro-chemical corrosion processes such as pitting and crevice corrosion. That all being said, I get the feeling that the people I have talked to in water treatment (nothing personal) really lack knowledge about the relationship between water chemistry and corrosion. Of course sharing information helps bridge the gap 
> Additional causes are > electrical current flow (dissimilar metals and/or electrical system > gorunding problems) and bacteria in the water colonizing the tubing.
There are many factors, some as you note, and others related to design and installation practices. Dissimilar metals (galvanic) corrosion cells tend to occur where a copper piping system has been joined to iron pipes/components without dielectric separation. Such corrosion tends to by isolated and non-systemic. Stray currents and grounding practices may be a factor. Also improperly balanced recirculation systems, use of acidic flux, unflushed debris, and burrs left in cut pipe and tubing. I am unaware of MIC (microbially induced corrosion) in copper water piping, although I have heard of reports of MIC in closed systems (fire protection or sprinkler piping). > The bottom line is that with aggressive waters and current water treatment, > copper of any thickness is just not standing up to localized corrosive > attack such as pinholing and crevice corrosion, especially in recirculated > hot water systems. > "current water treatment" meaning the water company treatment which does > not include ion exchange water softening, not water treatment done by > their customer.
Well actually, I meant the municipal water supplier as we tend not to have much water treatment in buildings because of our already soft and relatively clean water. Of course every city/area is different depending on the nature of the water source and treatment employed by the water utility. > Some things that the copper industry does not want people to know about. > BTW the replacement industry is Big Business > They and those sold on copper being ‘the best’ material, including codes > personel and others.
Sad but true! However, things are changing! BTW, a considerable portion of my work comes from retrofitting failed water systems in buildings containing copper based water piping. Of course I specify more appropriate materials for the repipe including PEx and CPVC, much to the consternation of the repiping contracting companies and (sometimes) local officials who may be "sold" on copper. – Hide quoted text — Show quoted text -> Check out my web page if you want to know more. > — > Duane M. Tilden PE > Crown Mechanical Consulting > Web: http://ca.geocities.com/duanetilden/Copper/Copper1.htm > I don’t have a web page……. but the web is full of ‘em. Many support > either side of any issue, kinda like doctors, lawyers and politicians. > There’s some POE/POU water treatment sites too. > Gary > Quality Water Associates
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I thought this might be helpful… http://www.copper.org/tubehdbk/selecting-tube.html
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> I thought this might be helpful… > http://www.copper.org/tubehdbk/selecting-tube.html
hummm IMBY and others I know of, you won’t find their lead being followed very much. Here/there M soft/hard is used/specified in low pressure hydronic heating, L soft/hard is used/specified for pressurized potable water and K soft (not sure of hard) is used/specified for underground service line. IMO copper has earned a bad reputation for failure when it has been direct buried in concrete, used with water that is acidic and/or aggressive and in hot water recirculating systems with certain water quality issues being present. Gary Quality Water Associates
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– Hide quoted text — Show quoted text -> I thought this might be helpful… > http://www.copper.org/tubehdbk/selecting-tube.html > hummm IMBY and others I know of, you won’t find their lead being > followed very much. Here/there M soft/hard is used/specified in low > pressure hydronic heating, L soft/hard is used/specified for pressurized > potable water and K soft (not sure of hard) is used/specified for > underground service line. > IMO copper has earned a bad reputation for failure when it has been > direct buried in concrete, used with water that is acidic and/or > aggressive and in hot water recirculating systems with certain water > quality issues being present. > Gary > Quality Water Associates
Well put, I’ll second that. Although I still see a lot of K hard temper being used in commercial potable water systems, and some are using L. This is changing though. In my opinion, CPVC and PEx have run the gauntlet and are proving themselves effective and preferred alternatives in the distribution systems. Make sure you get the spec’s right though because all brands are not the same. Personally I spec Flowguard for CPVC and Wirsbo for PEx. That being said, there are areas that copper is still preferred, especially in mechanical rooms. Duane
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– Hide quoted text — Show quoted text -> Can anyone tell me why and where I would use each of these Types of > copper piping? > TIA >I know others have but… Usually speaking; M for low pressure hot water >systems like baseboard heat. L for pressurized water lines. K for >underground water service lines. I believe all three come in rigid and >’soft drawn’ coils, I know L and K do. All three have different pressure >ratings with K being the highest, L lower and M the lowest (100 psi). >My advice is to use copper only where the water is not >aggressive/corrosive, otherwise use plastics. >Gary >Quality Water Associates
I would be very careful about using plastics anywhere in a domestic water system. Check with your local code enforcement people to be sure. With regard to type-M, I have not seen it in annealed rolls. Mostly, I see type-K in rolls because most people use the soft stuff underground where you can’t see it and the rigid stuff above ground where it makes a neater appearance. The hard-drawn stuff technically has a higher pressure rating because of the work-hardening inherent in drawing the tubing. Though the ratings of the stuff are so far above the actual operating pressures seen in most systems that it really makes no difference.
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> Can anyone tell me why and where I would use each of these Types of > copper piping? > TIA
I know others have but… Usually speaking; M for low pressure hot water systems like baseboard heat. L for pressurized water lines. K for underground water service lines. I believe all three come in rigid and ’soft drawn’ coils, I know L and K do. All three have different pressure ratings with K being the highest, L lower and M the lowest (100 psi). My advice is to use copper only where the water is not aggressive/corrosive, otherwise use plastics. Gary Quality Water Associates
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– Hide quoted text — Show quoted text – > <snip for brevity> > > Up here in Vancouver we are experiencing many failures of copper piping > > systems within 20 years and in some cases the systems will fail in 10 > years > > due to pinhole corrosion failures. Our water is from a protected > > watershed/reservoir which is very soft (low mineralization) and > aggressively > > treated with ozone, chlorine, CO2 and other additives. Our water is > also > > saturated with oxygen and CO2 due to it being an atmospheric source. > Correct about causes of corrosion and I notice there’s no mention of ion > exchange softening. As there shouldn’t be. > No mention of softening because as you would surmise from the chemistry of > the water in question softening treatment is not required. However, there > are > other issues such as micro-filtration, ozonation and UV sterilization as > well as > some form of mineral additions which are being sold as building water > treatment > options.
I treat that type well water in my area of PA and in some cases the hardness is up to 6