fittings

brettdotcom14 · Mon May 04, 2009 12:38 pm

quick question what kind of fittings should i be looking to use?

ive been reading that dwv fittings are no good and my local lowes only sells dwv fittings. i wish i could use lowes cause i have a giftcard for them.

covey12 · Mon May 04, 2009 1:36 pm

well if you doing a combustion dwv shouldn't be that big of a problem from what i hear, and from personal experience they do fine at 40psi

brettdotcom14 · Mon May 04, 2009 1:38 pm

yeah im not worried about my combustion cannon im more worried about my future pneumatic cannon. i plan on going over 40psi. just wondering what the safest kind of fitting would be

jmeyer1022 · Mon May 04, 2009 1:44 pm

NSF-PW sch 40 fittings are fine check out
http://www.flexpvc.com/cart/agora.cgi?p ... -outlet-90

Cheap fittings, large sizes, and all pressure rated. Just click on what you need on the side.

Technician1002 · Mon May 04, 2009 1:49 pm

brettdotcom14 wrote:yeah im not worried about my combustion cannon im more worried about my future pneumatic cannon. i plan on going over 40psi. just wondering what the safest kind of fitting would be

Flanged malleable iron steam pipe, unless you dropped it on your foot.

The safest but hard to work with would probably be HDPE pipe. It isn't brittle like PVC and is rated for compressed gas. Most hobbyists don't have heat fusion welding equipment.

A great article covering the subject is here;

http://www.hydraulicspneumatics.com/200 ... 6547/Issue

An attractive alternative to PVC

New thermoplastic piping systems -- using high-density polyethylene (HDPE), for example -- overcome the brittleness problems associated with PVC. They efficiently and reliably deliver compressed air with lower material and installation costs and longer service life than with metal systems. They offer a margin of safety missing from PVC.

Biopyro · Mon May 04, 2009 2:38 pm

I can also never find anywhere stocking large diameter HDPE. It's a fantastic material, but the only places I have ever seen selling it sell 100m coils up to 50mm diameter.

DWV is no problem for combustion, but really isn't worth the risk for pneumatics. I believe some lowes do stock pressure rated stuff, so you could try out of town?

jmccalip · Mon May 04, 2009 3:40 pm

Just find a plumbing supply company near your house. Most are business to business sale only, so you might have to use your work as the company name. Luckly, my supplier doesn't require this.

It's much cheaper than ordering online, and I don't have to pay outrageous shipping. Plus I can get a 3" shd 80 tee for $12(sorry Mr. Crowely

).

Hotwired · Mon May 04, 2009 4:18 pm

Pff, all these new fangled plastic whatnots.

BACK IN THE DAYS OF 1988 THERE WAS JUST THE ONE...

OSHA thingy wrote:Only one type of plastic pipe has been approved for use with compressed air. That pipe, Acrylonitrile-Butadiene-Styrene (ABS), is marked on the pipe as approved for compressed air supply.

brettdotcom14 · Mon May 04, 2009 6:50 pm

i actually found out my lowes carries quite a few nsf-pw. everything i needed except a 4"-2" reducer for my pneumatic. and a cleanout adapter for my combustion.

**QUESTION THOUGH**

i bought 2" pvc-dwv pipe but its rated for 280 psi is that okay to use? i assumed it was since it has 280psi rating

jmccalip · Mon May 04, 2009 7:21 pm

brettdotcom14 wrote:i actually found out my lowes carries quite a few nsf-pw. everything i needed except a 4"-2" reducer for my pneumatic. and a cleanout adapter for my combustion.

**QUESTION THOUGH**

i bought 2" pvc-dwv pipe but its rated for 280 psi is that okay to use? i assumed it was since it has 280psi rating

Does it also say NSF PW? It might be a dual purpose pipe, that's what I used for my 4" chamber.

brettdotcom14 · Mon May 04, 2009 7:55 pm

yes it does has the NSF-PW on it also. didnt see that before guess its all good

ramses · Mon May 04, 2009 8:06 pm

then it is fine. in general, if something has a pressure rating on it, it is good to use up to that pressure. you were right to err on the safe side, though.

You could start putting reducers in series for your 4" to 2". just start connecting bushings like a 2"-3" into a 3"-4". bushings are rated for pressure more often then bell reducers, and you don't need to buy a section of intermediate pipe to connect them.

brettdotcom14 · Mon May 04, 2009 8:21 pm

i looked at the bushing too they werent nsf-pw either so ill have to find some either at another store or online. still need to find sch 40 4" pipe too

jmccalip · Mon May 04, 2009 11:14 pm

brettdotcom14 wrote:i looked at the bushing too they werent nsf-pw either so ill have to find some either at another store or online. still need to find sch 40 4" pipe too

Try going to a small hardware store(like Ace) for the 4" pipe. They always seem to have the 4" pressure rated. Just make sure you call first.

brettdotcom14 · Tue May 05, 2009 11:41 am

thanks for the info ill check it out later today