SpudFiles

Well from what I have garnered here, ( I am into guns that you pump with good ole air) combustions usually don't go up that high in pressure.

well, i looked back at calcs and see now that i mistook one of the variables

i cant know the presure till after i fire it

As to the max combustion pressure of a combustion gun...

A stoichiometric propane/air mixture at atmospheric pressure can produce a maximum of 102psi, minus 14.7 for atmospheric comes to 87.3psig. Theoretically, that is. This is assuming *perfect* conditions and does not take temperature, humidity, etc... into account, so the real number is probably a bit less than that. I'd estimate around 80psi for the average propane metered gun.

Peace,
Pete Zaria.

thank you I only got 1 year of chem under my belt

but back to the topic at hand does anyone need ABS pipe

well now that we established that you could use SCH 40 pvc for a much cheaper price aren't you going to buy pvc of is it too late and did you already order it? i have a simple sch 40 combustion and there hasnt even been anything that could consider to be a rip or crack.

If you can get Pressure rated ABS for a bit more then PVC go for it better to be safe then sorry.
(Can't believe I just posted that)

lukemc wrote:and there hasnt even been anything that could consider to be a rip or crack.

How about a hair line fracture.

key word is simple, mine is going to evolve, probly have 5 upgrades as things work

alltogether the pipes are going to be like $150, and im going to have a crapload extra, so if anyone wants some i will think bout buying it so i can sell the extras

well buying abs for safety is pretty dam stupid...u say it is rated to 200 something psi??? well almost ALL sch 40 pvc that ISNT cellular core or foam core is RATED to 330 psi....much much safer....buying it for the looks would be very stupid just use black paint...and also why use pressure rated pipe in a combustion???i used mostly dwv in my combustion (my dwv is rated to 150 psi) but still....its retarded if u ask me...spending 150 on ur first gun JUST for pipes is OUTRAGOUSLY OUTRAGOUS......my first gun cost at most 25-30 dollars...unless this is propane metered or mapp metered dont bother

propane first

then propane-oxygen later

are you sure Sch 40 PVC is rated to 330psi?

Guys.... for god's sake, this is all over this website... I've posted this myself at least 5 times now....

Schedule (SCH40, SCH80, etc...) is JUST A MEASURE OF WALL THICKNESS - NOT A PRESSURE RATING!!!
3 different kinds/sizes of SCH40 pipe could have 3 VERY different pressure ratings.
NSF-PW (xxxpsi) is a rating. Sch40 is not.

@Spudthug,
Sorry to say it, but you're just wrong about sch40 pressure ratings. Nowhere near "almost all" pvc that's not cellular core is rated to 330 - LOTS of it is rated to well under 200psi. This includes most sizes of NSF-PW PVC SCH40 over 4" that I've seen, most categories of CPVC over 2", most class 120, 160, 180, and class 200 pipe, most SDR pipe, etc...

However you're quite right that pressure rated pipe is not required for a combustion - in fact, cell core ABS is probably the best choice for a combustion - if it DOES fail, it just rips open clean and doesn't shrapnel much, if at all.

Peace,
Pete Zaria.

but will cellular core be ok with propane?

sandman wrote:but will cellular core be ok with propane?

Cell core ABS, yes (no cell core PVC, though). My old gun was ABS cell core DWV, 4" chamber, 1.5" barrel, propane injected, chamber fan, it saw over 500 shots before I took it apart. My current over/under is ABS DWV, it's seen at least 100 so far and it's holding up wonderfully.

Peace,
Pete Zaria.

spudthug wrote:well buying abs for safety is pretty dam stupid...u say it is rated to 200 something psi??? well almost ALL sch 40 pvc that ISNT cellular core or foam core is RATED to 330 psi....much much safer....buying it for the looks would be very stupid just use black paint...and also why use pressure rated pipe in a combustion???i used mostly dwv in my combustion (my dwv is rated to 150 psi) but still....its retarded if u ask me...spending 150 on ur first gun JUST for pipes is OUTRAGOUSLY OUTRAGOUS......my first gun cost at most 25-30 dollars...unless this is propane metered or mapp metered dont bother

My first basic simple as you can get combustion cost me that much($150). Not all countries are as privileged as America when it comes to pipe, My Dam Buster cost me well over $350US where it would only cost you guys around $150-$250US.

Pete Zaria wrote:

sandman wrote:but will cellular core be ok with propane?

Cell core ABS, yes (no cell core PVC, though). My old gun was ABS cell core DWV, 4" chamber, 1.5" barrel, propane injected, chamber fan, it saw over 500 shots before I took it apart. My current over/under is ABS DWV, it's seen at least 100 so far and it's holding up wonderfully.

Peace,
Pete Zaria.

but do you think it could hold up to the propane-oxygen upgrade i plan to give it


and by adding on to the cannon in stages i hope to save costs in the long run

propane and oxygen?
I haven't used it in a cell core gun, but it sounds no good in cell core.