P-trap operational limits ??

Getting ready to install plumbing for new tub install, and wanted to know ahead of time if there are any limitations when installing the p-trap. I know that the standard trap is a fairly tight radius. If need be, could a trap be made with two 90o elbows with a straight connecting pipe at the bottom ? if so how long can connecting pipe be so that the trap still functions correctly? (1", 3", 12" ???) If not, is it because the trap operates more efficiently with a tight turn in a shorter length?

Also, where there will be no access to the plumbing after the tub goes in, is it better to use only glued joints in the ABS plumbing?

Thanks

 

Built-up p-traps are generally made up of a 90 plus street 90. The short bend promotes "scouring", so sediment and deposits are minimized in the bend. The plumbing
codes REQUIRE no-access drains to be made up of glued (solvent-welded) or other approved joints.