Welding PVC ball valves

[Flapper]

When welding PVC ball valves, is it ok for the glue/primer to touch the ball/seal stuff? I think it would be difficult to avoid when gluing ball valves with slip joints.
Today I ran into a bit of a worry. I had a ball valve, one end connected to the water supply, which was on, and the valve was closed. The other end had a male thread to slip adapter, and I was gluing pipe into it. The valve was tilted with the adapter upwards. After applying the primer, I found that primer had pooled at the end with the ball. I wasn't sure what to do. Do I leave it there or flush it out? Could it contaminate the water supply if I open the valve? If I leave it there, then it would probably stay there and have to be flushed anyway, but through more pipe...
After some hesitating, I flushed it out by opening it completely for a few seconds.
That got rid of it but of course it left a stain...

So anyway is it ok for primer to touch the ball? The damn primer gets everywhere!

 

[Jadnashua]

Primer has some solvents in it and may damage the sealing surface, and under the right (wrong!) circumstances, could weld the ball in place. It is designed to both clean and soften the pipe prior to adding the cement which also has some dissolved plastic in it to help fill in the voids along with the solvents.

 

[Sponsor]

 

[Flapper]

Well the ball valve is working fine so I think it's alright.