First I'll remove the old valve by cutting the pipes, then glue on new
3/4" PVC pipes to get the new valve well above ground level. Then
screw 3/4" fittings into the female openings of the valve. NOW, HERE'S
THE QUESTION: it seems difficult to get the fittings onto the pipes
because twisting is impossible. Do you just put on a lot of blue glue
and quickly shove both sides (valve and antisiphon) on? Twisting is
supposed to give a better seal. One way I thought of is apply the glue
in all 8 places (both sides of each pipe and all 4 fittings (2 for the
extension and the 2 in the valve unit), have a helper push down on the
valve unit while I hold the extension pipes, one in each hand, and
twist them both into their top and bottom fittings at the same time.
And we get only one chance to get it right. Advice appreciated.