Do you mean the old black alkathene? Yes it can and should be.
Yes it should be
24 inches.
24 inches.
Yes.
Black pipe is an amateur term for common steel or iron pipe.
You need to give more info than simply "rigid pipe". What kind of "rigid pipe", what pressure will it have and where you are burying it.
a black pipe can not be used in plumbing.Of course black pipe has many used in "plumbing" gas fitting and steam fittingPneumatic lines are specified as black , Fire suppression systems black pipe, gas piping , oil supply , steam and hydronics black pipe
Bi pipe is a black iron pipe.
Black of course
With a pipe threader.
Sir Walter Raleigh was buried with a pipe and tobacco. His coffin was also "lined throughout with the wood of my old Havana cigar-boxes."
Francis Drake