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Posted: Sun Aug 09, 2009 5:54 pm
by mobile chernobyl
The inside of the Tee or Wye if sch 80 will most likely be too small for a piston to transition through it and into the pipe. We use sch 80 PVC 3" piping at work all the time and with the tee's the inside of them (not the socket, the actual inside of the fitting - dewey-1) is smaller than the ID of the 3" sch 80 piping... I can only assume it would be the same with 4".

Posted: Sun Aug 09, 2009 6:06 pm
by c11man
mobile chernobyl wrote:The inside of the Tee or Wye if sch 80 will most likely be too small for a piston to transition through it and into the pipe. We use sch 80 PVC 3" piping at work all the time and with the tee's the inside of them (not the socket, the actual inside of the fitting - dewey-1) is smaller than the ID of the 3" sch 80 piping... I can only assume it would be the same with 4".
man i wish i got to work with my favorite material, pvc. so your saying that to get a sch 80 tee to work you would need to say have a 2.5inch piston and 2inch porting housed inside of a 3inch tee. just one more reason to get a sch 40 wye. im still waiting for the email back from Savko if they have a pressure rated 4inch pvc wye. im guessing it will come mid monday

Posted: Sun Aug 09, 2009 8:05 pm
by dewey-1
mobile chernobyl wrote:The inside of the Tee or Wye if sch 80 will most likely be too small for a piston to transition through it and into the pipe. We use sch 80 PVC 3" piping at work all the time and with the tee's the inside of them (not the socket, the actual inside of the fitting - dewey-1) is smaller than the ID of the 3" sch 80 piping... I can only assume it would be the same with 4".
That could very well be.
I am going by CAD drawings of both Spears and Charlotte Pipe.
Those two brands have 2D/3D drawings available.

Do you know the brands of the ones you are referring to?

Posted: Sun Aug 09, 2009 8:31 pm
by c11man
were are you getting these cad drawings of the fittings? cuz that could help out with some designing

Posted: Sun Aug 09, 2009 8:50 pm
by mobile chernobyl
dewey-1 wrote: Do you know the brands of the ones you are referring to?
We primarily work with Spear's pvc in the larger (2"+) sizes.

And don't use the cad drawings as a crutch!! it has gotten our CAD'ist (the guy who does all the autocad work) at work in trouble ALOT of times! things are more often than not different than their respective cad blocks. Another thing to note with cad blocks is that with something like PVC - only the outside dimentions will be held in tolerance to deal with interference's on the design, the inside dimensions could easily be very different than shown in the cad block, not to mention they will leave off irregularities that come in the forming process.


Basically unless it's in your hand, don't always believe the cad blocks! only trust what you can hold, then the best thing is to go back and revise the cad block's to be accurate to what your working with.

Posted: Sun Aug 09, 2009 9:10 pm
by c11man
mobile chernobyl wrote:
dewey-1 wrote: Do you know the brands of the ones you are referring to?
We primarily work with Spear's pvc in the larger (2"+) sizes.

And don't use the cad drawings as a crutch!! it has gotten our CAD'ist (the guy who does all the autocad work) at work in trouble ALOT of times! things are more often than not different than their respective cad blocks. Another thing to note with cad blocks is that with something like PVC - only the outside dimentions will be held in tolerance to deal with interference's on the design, the inside dimensions could easily be very different than shown in the cad block, not to mention they will leave off irregularities that come in the forming process.


Basically unless it's in your hand, don't always believe the cad blocks! only trust what you can hold, then the best thing is to go back and revise the cad block's to be accurate to what your working with.
if we can only trust what we can hold than how can we trust the above post? i cant hold it, its just a bunch of 1's and 0's.

jk what do you guys use that pvc for?

Posted: Sun Aug 09, 2009 9:33 pm
by mobile chernobyl
We use it when the job doesn't require sch 10 316L stainless piping to be used.

The company produces water purifying devices which produce just about the purest water that can be had in large amounts. Stuff it would be used for primarily is power plants for the boiler vessels and steam turbines. Also some silicon microprocessor lab work and sometimes medical stuff, although medical stuff requires clean rooms for fabrication which we don't do.

pressures are typically under 70psi for the media filtering vessels and electrodeionization (EDI), but for RO (reverse osmosis) the feed side can reach 250psi + so that's where the sch 80 comes in (neccessary when you factor in certain factors of safety, water hammer effect, water velocity etc.), although we use it on the permeate and concentrate lines as well which see quite significant pressure drop through the membrane.

Posted: Mon Aug 10, 2009 11:09 am
by c11man
sounds like a nice job.

still no word from Savko about the wye. if they do not have one i will go with a cross, but i realy want to do a wye

Posted: Mon Aug 10, 2009 1:43 pm
by dewey-1
mobile chernobyl wrote:
dewey-1 wrote: Do you know the brands of the ones you are referring to?
We primarily work with Spear's pvc in the larger (2"+) sizes.

And don't use the cad drawings as a crutch!! it has gotten our CAD'ist (the guy who does all the autocad work) at work in trouble ALOT of times! things are more often than not different than their respective cad blocks. Another thing to note with cad blocks is that with something like PVC - only the outside dimentions will be held in tolerance to deal with interference's on the design, the inside dimensions could easily be very different than shown in the cad block, not to mention they will leave off irregularities that come in the forming process.


Basically unless it's in your hand, don't always believe the cad blocks! only trust what you can hold, then the best thing is to go back and revise the cad block's to be accurate to what your working with.
I did not use anything for a crutch!
I made the disclaimer that it was based on their CAD drawings.

I do agree with you than it is better to have it in your hands.
In particular for use in their non intended use as we use in spudguns.

Would you be interested in assisting me with correcting sch 80 tee drawings?

I am thinking to get correct internal dimensions on just tees of 2, 2-1/2, 3 and 4 inch sizes. I will do all the drawings if you could just verify and/or correct via redline method on CAD drawings..

If you are interested in having correct drawings made let me know.

We can do further communications via PM or e-mail.

Posted: Mon Aug 10, 2009 7:18 pm
by mobile chernobyl
Yea sorry Dewey - didn't mean that as a something I would yell, just meant it as a casual suggestion.

I'll see what I can do I'm about winding down now for the summer and will be going back to school in 2 weeks. The largest size we carry in PVC is only 3" sch 80 fittings though - right now most all of our work is in SS.

Posted: Wed Aug 12, 2009 6:44 pm
by c11man
yay! i found a sch 40 pvc wye for a good price, i was able to talk to Savko and he talked to Dura plastics and he is able to get one and sell it to me for $31 so i will place my order tonight and begin building as soon as i get the order!

Posted: Wed Aug 19, 2009 6:38 pm
by c11man
i got the order today! and i ended up decidending on getting the sch 40 wye. when i opend up the box and looked at it i thought aw sh!% because it looked like dwv. but it turns out its a SCH 80 wye! i didnt realize it at first because its the pure white of sch 40. i have no clue how i got a sch 80 4inch wye for only $31, (i am going to call savko tomarrow, not complaining but curious). but what we had discussed in this thread that might be a problem is the ID of the fitting between the sockets. this turned out to be a god send, becuae i can just use this smaller diameter area as the piston's guide tube. it is smaller at 3.75 so i did modify my piston accoridingly form 4inch but this will give be and even more powerfull valve because it will snap open like a qev. my triggering pressure is now going to be 12.5% of the chamber volume. and some pics of this massive fitting

<a href="http://s696.photobucket.com/albums/vv32 ... 0_8840.jpg" target="_blank"><img src="http://i696.photobucket.com/albums/vv32 ... 0_8840.jpg" border="0" alt="Photobucket"></a>
to show scale i put in my new coax pelet gun (in showcase soon) and that brass chamber is 11inches long
<a href="http://s696.photobucket.com/albums/vv32 ... 0_8839.jpg" target="_blank"><img src="http://i696.photobucket.com/albums/vv32 ... 0_8839.jpg" border="0" alt="Photobucket"></a>
to prove that its sch 80
<a href="http://s696.photobucket.com/albums/vv32 ... 0_8837.jpg" target="_blank"><img src="http://i696.photobucket.com/albums/vv32 ... 0_8837.jpg" border="0" alt="Photobucket"></a>
and to show thickness, the tee is a pressure rated and it looks wimpy....
notice my beast of a computer in the back?

now if i break this wye i am either doing something very wrong or very right! 8)