Anyone Cutting threads on PVC?

[Tony Pezzolo]

Hey everyone. I am just getting started here. My mind keeps crunching away at system designs. I would just like to start with something small, like a single barrel system.

Just wondering if anyone out there is using a tap and die set to cut threads on PVC? Sure would be handy. If you are, what are you using??

I have been searching the net some. Most of the NPT tap and die kits only go up to 1/2 inch. After that, the tools get much more expensive.

Also - anybody know what size PVC this piece threads into? I sent an email off to customer service but have not heard back.

http://www.theaquaponicstore.com/Flood-and-Drain-Fitting-Debris-Scr...

Thank you everyone.

[Kevin Gorham]

Hi there,

I currently work for an aquaponic project where we were planning on drilling and tapping a series of 1/2" NPT holes into a 2" PVC air manifold. We looked at having a CNC machine shop do it for us, and at doing it ourselves, until we spoke to a local irrigation supply store who told us to simply use a threaded T fitting.

Instead of drilling and tapping holes, why not use a premade fitting? We got 2" to 1/2" threaded T's, with the 2" being slip connections and the T having threads. You could cap off one end of the T, or they also make a fitting called a "street L" where one side of the fitting is slip and the other side of the 90 is threaded. You can also get that in different sizes. 

[Vlad Jovanovic]

Not sure about that debris screen/strainer...but these http://www.aquaticeco.com/subcategories/5023/Plastic-Strainers

are made from 1/2" up to 2" (mine are 1-1/2" MNPT)

I've only hand tapped 1/4" on PVC

I'm lucky enough to have a cousin right down the road with real decent machine shop, but the only reason I've had to use the lathe and bigger taps is because many of my parts/pieces are NPT standard (U.S) while many are ISO (metric). So the tapers and threads don't quite mesh with one another (they look like they do to the hand and eye, but the wont hold water/air. You being in California...I imagine whatever you would need would be a couple clicks away?

[George]

I spent a lot of time in the plumbing department fiddling around with parts.  I tried using slip connections with no glue but ended up gluing most of them due to leaks.  I did used threaded parts in some places, like the connections to my pump, so I can easily replace it - in those places I used a screw to ensure that the connection doesn't come apart.  There has been some discussion about the need to take pipes apart to clean them but I seriously doubt that will ever be necessary unless you are using very small pipes. 

[TCLynx]

for pvc most of the possible fittings are available at a reasonable price if you know where to look, there is not much benefit to messing around with making your own threads unless you are talking about doing something like threading very small pipes into very large schedule 40 or 80 pipes where the fittings start to get rather $$$$$  Like for instance say hooking a bunch of 1/2" or 1" outlets to a 4" main pipe or somenting.  But I would probably just go with uniseals for that myself, far easier.

If you needed to do 1/4" off of say 1" pipe I could see threading them like Vlad said but I would never use 1/4" tubing in aquaponics since it will clog all the freeking time!!!

I just use lots of 1/2", 1", 1 1/4", 1 1/2" and for my SLO drains I often use 3" or for big systems 4"

They make 1" to 1/2" threaded Ts or you can get those snap on Ts that you then drill through and they have the treaded fitting already so they are great for tapping into an existing line, sometimes they are called saddles and they are very commonly used in irrigation situations where getting enough elbow room to actually install a T in the line would involve too much digging so they glue on the saddle and drill the hole, thread in the new riser and boom.  I've used such things for my tower systems where a line of towers will be fed from a 1" line and at each tower I T down to a 1/2" threaded elbow and it goes down to a Cap with a hole or slit cut in it and a bottle with the bottom cut off to contain the spray/splashing.

Don't skimp too much on the plumbing because it will cost you more to replace cheaper stuff with the right stuff than it will cost you to use the right stuff in the first place.  Pumped water needs to flow through pipe at least as big if not bigger than the fitting on the pump.  Gravity drains should be at least twice the size of the pipe feeding a tank or bed (siphon stand pipes being an exception to an extent.)  So if you are feeding grow beds with a 1" feed, then the combined drain needs to be at least 2" and perhaps larger depending on the amount of pressure going into the beds and the length/fall of the drain.  A powerful pump feeding through a 1 1/2" pipe can overflow a fish tank with a 3" SLO drain so always make sure you have a means to bypass some flow in case your drains can't keep up but make sure your drains are big enough to handle the required flow for your application.

[Tony Pezzolo]

Thanks all for the information. Than you Vlad for that link, and thank you TCLynx for the system design advice. I was just figuring that a tap and die set would come in handy for those instances, you could make a piece at home instead of driving to the hardware store and hunting the isles.

[Vlad Jovanovic]

Yeah, the 1/4" tapping was for an air-lines... And also, I pretty much live in an economically deprived shit hole of a country, so fabrication of common or household items has become a favorite past time of mine, and at times a bit of a sport...

I imagine your right TC, a 1/4" water line might last a whole 5 minutes in AP before being bio-slimed tighter than Chris Farley's arteries...

I'd listen to TC and just buy the stuff you need... unless your a masochist, a hardcore do-it-yourself-er, or feel really, really stupid paying for something you 'can make yourself'...even if making it was more hassle than earning the money that it cost you to buy it).

behold...http://www.mcmaster.com/#plastic-pipe-fittings/=i7v0q9  (thank you Stephen Corbett)...the porn site of the AP plumbing realm...should have what you need...

[Tony Pezzolo]

Vlad - Good info Vlad, thanks. California doesn't qualify as an ecomnomically deprived county, I am sure. But I feel like those days are just around the corner. I'm sure it is all relative. I'm not a hardcore DIYer, but money is a valuable thing. I also have the hobby of restoring motorcylces and have gotten pretty handy with a tap and die kit. I feel like it saves time and money if I can make or repair a piece at home than going out hunting for it. Not to mention I can never find what I need at a hardware store. It might be a genetic disorder.

[Rob Torcellini]

I tap PVC all the time.  Usually, it's 1/4" to 3/4" in size and is very easy to do.  I bought my die set from Harbor Freight and a few taps from ebay.  I'm not sure what size the threads are on that screen.

[Bob Rogers aka The White Lion]

Why would you expend the time cutting threads ?  there are so many fittings with the threads already made to fit. just cut your pipe and add the fitting. The money you save on the taps and dies could be better used on something else ... like food for the fish maybe.