SpudFiles

Well i finally getting away from the spray and pray spud guns and going into the advanced spud guns so far i've got the meter built and working and the barrel (1and1/2 in. 6ft pressure rated). But i need help on connecting it to 3in. chamber. I know you shouldn't use the bell reducers and use bushings but im confused on how they work (the bushings) and i cant find any pressure rated ones ether.

Bushings are simply the flat cousins of bell reducers. Most bushings are pressure rated. Unfortunately, you won't find anything besides endcaps for 3in and up at any kind of standard hardware store. You'll have to find a plumbing shop (Fastenal for example) to get those kinds.

But, you're building a combustion, so bell reducers are perfectly fine.

Thanks i'll half to look for one around me. Not saying your wrong but i read that you should only use bushings for propane powered ones not bell reducers?

No, that's with pneumatics and hybrids. Combustions don't produce enough pressure for long enough to be a safety concern. Bell reducers are fine on any combustion. Except if you're Larda and you can work with hydrogen or something.

ALright then do they make pressure rated bell reducers? If so ill get those when i go for my pipe and end cap.

yes but they are extremly rare except for online

Bushings are the same outer diamter as the pipe, so they fit in pipe sockets, such as couplers or other bushings. Most stores have 3" to 2" bushings, and 2 to 1.5" bushing, add a 3" coupler and you're set.

you can use these two fittings from Graingers

2ERA1
6NF58 or 1WKH4

Ralphd Im going to get the coupling and bushing you showed thanks everybody for the help.
EDIT well None of the stores near me carry presure rated PVC pipe anymore so that puts a halt on my project until i can find some locally (they just carry some soft core stuff not sure what it is but it says not for pressure on it so i dont want to use it.)

Don't use a non-pressure rated bell reducer. While they can pass on a noob gun, don't use one if you know better.

If you want to build a really nice combustion, consider the option of a burst disk attachment. The pressures will get up higher than a standard combustion in that case.

I got another question i have one of those end caps that have the threads on it then you screw on the plug are those safe to use? I couldnt figure out if thier pressure rated or not.

Sounds like your talking about a cleanout cap. Just about any combustion you see will have one to aid in chamber venting. Just make sure you have good threads and you should be good.

Errr...some threaded plugs are pressure rated, while others are not. You can tell by checking to see if they have nsf-pw printed on them.

Either way, I would avoid standing directly behind one, they have a history of blowing off.

Yea i was looking at mine and i cant seem to find anything DWV or nsfpw on it. I know alot of people use them i was just wondering if they were using nsfpw or DWV. So my question is even if mine was DWV would it be safe? That would be the only DWV piece on the cannon.

Well the cannon is only as strong as it's weakest part, but for a simple combustion you should be able to get away with DWV anyways.