replacing irrigation valve

[imafan26]

I have to replace a leaking irrigation valve. Any tips on how to glue it without being able to twist it to seal. My last attempt took me half a day and 4 tries to get it to where it did not leak or come apart. I have 5 more valves to replace.

The rubber gasket is what is leaking. I have Richdell valves and the company is now defunct. The valve is 20 years old, so I have to replace it with another 1 inch valve. The malfunction with the sprinkler probably was the root of a lot of problems I have been having with the weeds.

[LIcenter]

A few pictures would help a great deal.