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So if I go to my neighborhood Home Depot I can generally find 3 types of pvc fittings: CPVC(yellowish pvc which i've been told is the one you want for potable water applications), PVC(white), and in the electrical department is a grey PVC used for conduit.

Does it matter which to use? Especially for things like bulkheads... (Finding proper bulkheads around here is challenging, at least if you are trying not to pay more for shipping that for the fitting itself)

I ask because the CPVC which is what I've been told by others is the 'safe' one of the three is the one with the least amount of selection in terms of size/type.

Thoughts? Recommendations?

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There are actually probably even more fittings than that cause there are different size ranges of white. The stuff that fits the schedule 40 and pressure pipe and then the stuff that fits the 3 and 4 inch sewer pipe.

The CPVC for potable water applications I think has more to do with putting it inside the house where it might be connected to the water heater and have to deal with more heat than the white PVC drinking water pipe can. The CPVC also tends to be smaller (much closer to PEX sizes) I wouldn't mess with the CPVC for AP unless you are dealing with some water heating to up closer to 140 F.

For the Most part the white PVC is just fine for our applications.

Now the gray well there is some dark gray schedule 80 stuff that is for water plumbing but I know when you say gray electrical conduit you are talking about the light gray stuff you find over by the electrical boxes and wire.
I generally wouldn't use the electrical conduit but on occasion people will use some of the fittings to do home made bulkhead type fittings because the electrical conduit threads are not tapered the same way the plumbing threads are so you can tighten those fittings all the way together around a tank wall.

Back to the white water pipe fittings and pipe. I use mostly the thinwall pressure pipe that is drinking water pipe for my feed lines from the pump to the grow beds but at my local store that seems to only go up to 1 1/4" size so for the big system I have to use the 1 1/2" schedule 40 PVC. The Pressure pipe is just lighter, cheaper, and easier to cut. The Schedule 40 is definitely sturdier if you need to run the pipe with little support or if it will be buried under a heavy traffic area. Both those pipes will use the same type of fittings so other than the interior opening in the pipe, they are interchangeable. This type of plumbing can also be used to run the distrobution for air lines as well. You can get nylon barb fittings that will thread into the threaded ball valves for the PVC, this way one is only running a small amount of the flexible air line so it is less likely to get smashed or cut.

for much of my drain system, I've been using the 3" sewer pipe. It is thin wall like the pressure pipe so could be crushed if you let something really heavy wheel over it. Anyway, it is easy to cut but I've found that I can't usually leave these pipe unglued as they tend not to fit as tight, and when down buried in the ground, pipes should be glued since one might not notice a leak. Tree roots are also good at working their way into the tiniest seep. Now it is important to look in the right section of plumbing bits for the sewer pipe fittings since the bell end sewer pipe doesn't share fittings with the DWV pipe.

By the time you are done with a few AP projects, you will know your way around the plumbing sections of your local stores better than many of the employees. :P

PCVP pipe can handle a temperature of 180 F and the diameter is smaller.

Regular PVC can handle 130 F, which I like to use the thicker ones.

The gray electrical pipes have a fire retardant incorporated specifically for electrical fires, which may leach more compounds into your system.

Don't get me wrong, pcvc and pvc have fire retartants build into also, but not as much as the gray electrical pipes.

What I like most about plastic pipes is that you able to make bends and turns without having to cut it and glue pre-manufactured bends/turns on to them. All you have to do, heat it up with an electric radiant heater ( one without a fan) or a heatgun and keep the pipe turning until it gets spongy, then you make your bend  and hold it's shape ...then you  take a wet rag   and cool it until the pipe is stiff again.

It is worth noting that "regular" PVC, like the matte grey electrical stuff, or what's sometimes used for drains, contains plastifiers, phthalates, which are likely to end up being released into the water, certainly when the water gets warmer or when the pipes are exposed to sunlight. And it is toxic, possibly carcinogenic.

The "good" types to use are UPVC (unplastified PVC) or CPVC (chlorinated, high pressure or high temperature).

It seems that in some areas what's just called PVC and used for water pipes is indeed UPVC, but it is worth verifying. UPVC is usually hard and shiny, and can be found in a range of colors, white, dark grey, light grey, transparent. CPVC is also hard and shiny, and often beige colored.

I'm in France. Everything they had in a normal hardware store is the bad kind, and is marked as being for drains. It took me quite some research to locate UPVC. Online stores for pool materials turned out to be the best source here, and it is often just labeled as "high pressure PVC".

I was thinking about using pex what do you think?

You gotta keep pex out of the sun.  And it takes special tools and stuff to connect pex together.  And it is normally smaller.  I tend to use larger pvc pipes for systems and for most of my systems 1" pipe is the smallest line I use and 3" pipes are for the combined drains, I'm not sure that would be realistic with PEX.

ok! got it, had the tools and some line left over from a job but I am sure your right it will be a 500 gal tank so I will be thinking of 1 inch

TCLynx said:

You gotta keep pex out of the sun.  And it takes special tools and stuff to connect pex together.  And it is normally smaller.  I tend to use larger pvc pipes for systems and for most of my systems 1" pipe is the smallest line I use and 3" pipes are for the combined drains, I'm not sure that would be realistic with PEX.

It used to be that PEX required special and very expensive tools, but SharkBite fittings work on PEX, so it's a simple job for any skill level any more.  But I agree about the size issues.  PEX would only be good for plumbing something like fresh water supplies.  It sure beats copper for both price and easy installation.


TCLynx said:

You gotta keep pex out of the sun.  And it takes special tools and stuff to connect pex together.  And it is normally smaller.  I tend to use larger pvc pipes for systems and for most of my systems 1" pipe is the smallest line I use and 3" pipes are for the combined drains, I'm not sure that would be realistic with PEX.

One added FYI note on Plastic pipe and fittings I discovered some time ago:

If you find that you like the ABS fittings because they are much more gradual in their bends (as they're designed for drain and sewer lines).... but you need to change form ABS over to PVC to take advantage of some parts you prefer to use that are PVC...there is a glue (sold and H.Depot and other plumbing stores) made for that purpose.  SO with this glue...you can join PVC stuff to ABS stuff. Pretty cool !

Bradly

 

Thanks Bradly.  That's really helpful information.

Bradly said:

One added FYI note on Plastic pipe and fittings I discovered some time ago:

If you find that you like the ABS fittings because they are much more gradual in their bends (as they're designed for drain and sewer lines).... but you need to change form ABS over to PVC to take advantage of some parts you prefer to use that are PVC...there is a glue (sold and H.Depot and other plumbing stores) made for that purpose.  SO with this glue...you can join PVC stuff to ABS stuff. Pretty cool !

Bradly

 

Hey Bob

About the PEX...I don't know if the product is better now...but some years ago- many cities don't like it used in plumbing houses due to problems (leaking, etc...)    {I'm in building work}

Copper is sky high in cost anymore,I know how to sweat copper but the cost rules it out for me.  I'd use PVC and ABS for supply and drainage myself... and intend to in my system shortly.

Good advice in Sylvias book (I think that's where I read it) that glueing all the fittings might not be preferable if you need to take apart to clean out "slime" later.   Maybe be good to use theaded plastic fittings at key locations so that you can disassemble sections should the need arise.   (I'd recommend Unions...but they are costly and sometimes don't work like you expect them to.)

@Bradly - I was certified to use PEX years ago, but now that Sharkbites have been invented it's open to the DIY home owner.  PEX is being used in the majority of new construction here in California.   I wonder if you might be thinking of PolybutylenePolybutylene was used heavily in the 80's but the connections were unreliable, and except for mobile homes it was never approved in California.

I'm a big fan of PEX.  It comes as large as 2" but I've never used anything larger than 3/4".   There is even an insulated version.

Hi Bob

I should have clarified that citys don't allow it in some applications.

If you do a google search under "Pex not allowed" you'll see what I mean about cities and agencies resistant to it.

So you're here in California?  I am too.  What part you live in? I'm in Hesperia (High desert at top of the Cajon Pass on the 15 freeway).

Bradly

 

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