Working with pvc

[trilinearmipmap]

Can someone point me to a website that explains the basics of working with pvc for someone who has never done this before.

How to cut it?

How to prime/glue it?

How to attach it to bulkheads, valves etc and how to split the flow from one pipe into two?

How to plan the routing of the pipe to minimize loss of pressure/flow?

Thanks.

[yifan917]

(1) PVC cutters

(2) PVC glue

(3) Depends on what type of bulkheads you have, if it's double-threaded, use adaptors (don't forget to use teflon tape), if it's single threaded, then you'll have to glue it.

(4) Use "T"s

(5) (A)I would measure to make sure every part is in correct sizes and lengths, then put them together WITHOUT the glues to see how they fit together, then glue them up...(use alittle amount of vaseline when you are pre-assembling them, so they will be easier to come out when you want to glue them)

(B)For your returns, minimize as many elblows as possible, you'll get faster flows with straighter routes

[trilinearmipmap]

Thanks for the advice.

I read a really good article about working with pvc a month or two ago and now I can't find it.

I am wondering about T's to split flow. For example a 1" pump output dividing into two 3/4" lines for the return from the sump. A regular T should cause loss of pressure/flow just from the shape of the T. Do they make "Y" shaped T's?

Also I'm wondering about the pro's and cons of flex pvc versus regular pvc, and how to glue the flex pvc. Also where any good Canadian mail-order places to buy all the plumbing parts, for those of us who live far from a Home Depot.

[StirCrazy]

Originally Posted by yifan917

(1) PVC cutters

(2) PVC glue

(3) Depends on what type of bulkheads you have, if it's double-threaded, use adaptors (don't forget to use teflon tape), if it's single threaded, then you'll have to glue it.

(4) Use "T"s

(5) (A)I would measure to make sure every part is in correct sizes and lengths, then put them together WITHOUT the glues to see how they fit together, then glue them up...(use alittle amount of vaseline when you are pre-assembling them, so they will be easier to come out when you want to glue them)

(B)For your returns, minimize as many elblows as possible, you'll get faster flows with straighter routes

above was a good description but a couple things.. if you are only going to be doing a limited amount of work with PVC don't worry about the cutters, they can be expensive and are only good up to 1" (unless there is a larger size I haven't seen yet) any wood cutting saw works awsome on PVC. so had saw, compound miter saw ect..

I personaly would not use vasaline in the dry assembly as this is a greese that you have to remove prior to gluing. Just dry fit your parts they are never that hard to take apart. In adition to the glue you want to use primer (look for clear glue and primer if you can fined it. the primer cleans the surface and allows the glue to work a lot better.

to prime and glue all you do is open the primer attached to the cap will be a cotton swab on a wire, run this around the end of the pipe and then the inside of the fitting it will be going into. this is fine to dry at this point but keep it clean. with the glue you do the same over the primed areaas and then pres them togeather hard and slowly twist them inside each other till it sets up.

a tip I will throw in is to not build it in to big of chunks with out putting a threaded union in. this raises the cost by about 5 bucks for each one but it allws you to install/remove in smaller chunks and makes life much easier.

as for bulkheads get a threaded bulkhead and then you buy a threaded to slip adaptor. the one end threads into the bulkhead and the other glues to the pipe.

I will take a bunch of pics of various stuff tonight and post it for you.

Steve

[BMW Rider]

To cut the pvc pipe for my new tank, I just used a small hand saw (a hacksaw works too) cutting it freehand. If you do choose to use a power mitre saw, be very careful. It is critical to hold the pipe solidly so that it does not rotate as the blade cuts through it. If the pipe is allowed to spin, the blade could grab and throw the pipe out of the saw violently.

[JimE]

I just have a couple things to add.

Vaseline - bad idea. grease & glue don't mix.

Use a pvc primer - the purple stuff is just as good, you just have to be a little neater if you care about looks. Same applies to grey glue. Glue should be applied over the primer WHILE IT IS STILL WET - don't let the primer dry ! Remember to hold the fittings together for 1/2 a minute or so or they can push apart on you.

Use silicone on threaded connections - teflon tape by itself tends to weep over time.

Flex pvc uses the same fittings & primer, different glue

Don't get all anal about flow through tees and fittings - it is usually insignificant. Too small of piping is the real flow killer. Bumping up one size from the pump discharge size is usually a good idea.

Most of these supplies are available fron pool/spa dealers.


Jim

[trilinearmipmap]

Thanks for all the replies.

For silicone on the threaded fittings, do you mean the same silicone as is used to glue glass ie. aquarium silicone?

[JimE]

For silicone on the threaded fittings, do you mean the same silicone as is used to glue glass ie. aquarium silicone?

Yep, just smear it on the male thread like pipe dope, screw it together, and let set up before pressurizing.

Jim

as an alternitive to silicone which i dont like to use on threaded fittings, I like to use liquid teflon, it comes in a can similar to the pvc glue and spreads on with the applicator provided, works great! non toxic too, flex pvc will give you the least amount of head loss as the curves are smooth, I prime and glue right away, all saws work but I do like my PVC saw, I also have pipe cutters for 1 1/2" pvc(steve), and they do go up to 2" but are only reasonably used for low pressure pipe, you would need to close them with a vice to cut scheldue 40pvc, if using hard pvc pipe using long sweeping elbows helps dramatically to improve flow, and steve's mention of using unions is as good as gold, you will hang yourself later if you ever have to take apart your plumbing and you didnt use unions...as said, test fitting is a life saver

edited for accuracy

[JimE]

dont go up 2 sizes or more as the weight of all the extrra water in your vertical pipe runs will increase head loss dramatical

So completely wrong I don't know where to start, sigh. It will do no such thing, other than to REDUCE friction loss and perhaps increase flow in a particular application.

if using hard pvc pipe using long sweeping elbows helps dramatically to improve flow

"Dramatically" is quite an overstatement IMO - slightly is a better term. If you understand friction loss and friction loss tables, they show that elbows typically aren't a huge "detriment" to a typical system. If long sweep elbows were so wonderous as everyone makes them out to be, they would be a standard plumbing item - which they are not.

Jim