Is that a Haywood Super II pump? The metal plate on the tank body is worn, but I can make out the model number being SP5???X15AZ where the ??? could be [Q or O or 0] [ L or 1] [Q or O or 0].Ok, you have a Hayward Super II.
I thought that you might have a Tristar.
I am going to get the high temp unions. This is an eye opener I didn't even know these fittings exist! Thanks so much for this information I am going to rework the piping. I think I will replace the pump inlet and outlet joints with these unions. I am also thinking the inlet to the Haywood filter where I have a 90 could use this union.In any case, you should get the high temperature unions
JamesW, I got the high temp unions in so now I have all the necessary pieces except one.What you're proposing won't work. You would need a female threaded union or adapter.
If necessary you can cut flush with the valve and the outside of the valve will take the next size up from the internal pipe size.
The internal size looks like 2", so the outside would take a 2.5" slip coupling.
You can use a coupling and a reducer bushing to get back to 2" or a reducer coupling.