The threads on our standard ball valves are all BSP female tapered. The majority of threaded pvc components connected to valves are themselves BSP tapered (male). Fittings a tapered male to a tapered female give an increased contact area and more likelihood of a successful seal. In contrast, fitting a tapered male thread to a parallel female often results in a weeping or dripping joint due to the small contact area of the threads.
Should you wish to connect a parallel thread, we suggest that you purchase a plain valve and a spigot : fbsp connector from here.
PTFE Tape - Please remember that for ALL threads, you should wrap a small amount of PTFE tape around the male thread. This prevents fluid passing the through the thread.