I bought pvc for my chamber that sez that it is sch 40 DWV then it has "astm F-891-00" is this ok 2 uze? my chamber is 3 inch and the barrel is 1.5 in! if not what will happen and is there ne sort of like something 2 do 2 shield me from the blast if it does xplode?!??! like tonz o duck tape? and if that wuld werk, what parts wuld i hav 2 cover? jus tha chamber? PLEEZ HELP!!!