Alternatives to PVC?

Biopyro · Mon Mar 23, 2009 4:37 am

That's really bad, I'm suprised I haven't heard about it before.
I understand if he didn't want to share the details, but did it shrapnelise?
I might start wearing saftey specs which firing my plastic guns now. I do it for most other things, it seems silly only to wear them if you're expecting something to come your way.

TurboSuper · Mon Mar 23, 2009 7:03 am

Yeah, safety glasses are always a good idea when shooting anything. A $1 bit of plastic that can save your eye? Sign me up.

Ragnarok · Mon Mar 23, 2009 8:54 am

I've been saying this for as long as I've been posting here. Safety goggles and ear protection, for any cannon, because they're a lot less trouble than losing an eye or your hearing.

Sure, I make my cannons as safe as possible, but safety is two parts - prevention (of an accident) and protection (from an accident).
In other words, do everything in your power to try and avoid an accident, but act as though it could still go wrong.

I don't mess around with my cannons, because they're not going to hold back if they decide they're going to mess with me.

rna_duelers · Mon Mar 23, 2009 9:09 pm

To me the best alternative to PVC for plastic is HDPE High Density Polyethylene.It's cheap,readily avaliable and very strong and resistant to all solvents.

If your going to do a test I can possibly do a test on HDPE fittings and pipe upto 350-400 psi and submit it to possible real life events such as being dropped from a height of say half a meter.

Biopyro · Tue Mar 24, 2009 3:14 am

HDPE is very strong, but it's resistance to solvents mean it can't be glued together. Other than that it's ideal for us.

You'd need to "glue" it in place with epoxy or similar to seal the joints, then bolt the joints together.

rna_duelers · Tue Mar 24, 2009 5:28 am

I can get my pipes/joins that all screw together

in HDPE

Or if your rich you could buy the joins which are plastic welded together with heat.

Biopyro · Tue Mar 24, 2009 11:49 am

Nice, I hadn't thought of threads (no idea why, seems so obvious). You could perhaps weld it yourself, but whether I would trust it to be pressure safe, I'm not sure...

oldchris · Tue Mar 24, 2009 2:25 pm

rna_duelers wrote:To me the best alternative to PVC for plastic is HDPE High Density Polyethylene.It's cheap,readily avaliable and very strong and resistant to all solvents.

Other than nicking it from an unobservant natural gas crew, where does one obtain HDPE pipe? I can find manufacturers, but not "retailers" on the web.

Biopyro · Tue Mar 24, 2009 2:35 pm

Damn we really can fail to see what's right in front of us sometimes!
Forgot that HDPE is commonly abbreviated to just PE in the piping world. The pipe itself tends to come in long coils (100m) here.

The fittings are typically compression or threaded, and for SDR 11, the max pressure is 12.5 bar and max diameter is 40mm.

thisnobody · Fri Mar 27, 2009 3:28 pm

are 1/8 npt fittings better for the pvc or should i use 1/4 npt when tapping the pvc chamber for my pnuematic cannon also on the plastic sprinkler valve

ramses · Fri Mar 27, 2009 3:41 pm

most people use 1/4" because useful fittings are directly compatable (quick connects, thread in schraders, etc.

either is fine, but you may as well go with 1/4", as it means less fittings, therefore less cost.

make sure you don't use DWV, and tap the chamber throught 2 layers of PVC.

thisnobody · Sun Mar 29, 2009 7:35 pm

what is DWV
and i will go with the 1/4
thanks

colty-bear · Sun Mar 29, 2009 7:40 pm

DWV- Drain, Waste, Vent means it's not meant for applying pressure to the pipe.

thisnobody · Mon Mar 30, 2009 3:15 pm

yeah thanks
always sch 40 or sch 80
got that

ramses · Mon Mar 30, 2009 3:48 pm

thisnobody wrote:yeah thanks
always sch 40 or sch 80
got that

make sure it actually says a pressure on it. sch 40 is just a rating of wall thickness. fittings should day nfs-pw. as long it has one of those, it is fine, regardless if it says nsf-dwv.

the wiki is a wonderful thing.