I am in the process of replacing the control valve for the sprinkler system in my mom's house. I ended cutting the pvc pipes as shown below.

I was thinking of ordering a Rain Bird DAS/ASVF-100 anti siphon valve.
My first question is that will this end connect to the new siphon valve that I want to order? This end shown below originates from the sprinkler timer (Rain Bird ESP-6) and attached to the old control valve.

My second question is what is the teal colored device on the right and is it replaceable? I tried unscrewing the L-shaped pvc that is connected to it and it wont budge.

Thanks in advance for the help