The environment where the new fuel valves are kept can also be a factor.
I found quite a few problems with distorted and cracking soft carburetor parts, O-rings and fuel valves before I installed a mini-split unit in my shop to better control the temperatures.
In the summer, I found my wall temperatures on my steel shop walls were reaching 140+ degrees, so I also applied thermal sheathing to the inside walls. Fortunately, I had installed when I built the shop.
My spare parts getting damaged is no longer an issue.
Just something else to consider....