[SEL] O.T.: Pipe Specifications

[P. Johns]

Actually. Number 12 may be a problem. There is something called a "Left -
Right coupling" that is used for gas pipes that are to be concealed. It is a
short length of pipe (nipple) and a coupling that has both left and right
hand threads. It is used to join to lengths together without the typical
ground coupling  that is more likely to leak. Basicly, when you are
tightening in the normal direction, the other end is tightening too; drawing
both lengths together. So if you pick up a coupling that has one end
knurled, you have one in your hand - left or right, it doesn't matter.

Paul in California

PS: The list is still funny; I just get over technical at times - I do have
Plumbing Engineering training that I rarely get to us; hence the
nit-picking.

PPS: yes, it does sound like a Gov'mt spec.

PPPS: You want one for your collection? Go to:
http://www.plumbingsupply.com/leftright.html