Cup seal and valve

[XSiv Force]

Is there a reason the the cupseal and the valve pin are two pieces instead of like a cocker with a single piece? Is it alright if the cupseal is made out of cobalt steel? Im trying to make a pmp valve pin for another piranha/spyder pump

[bigred76]

The reason is that delrin, which makes up the cupseal, is a very brittle product. As it wears, you need to be able to replace it. Thus, replacing just the cap of it is a lot cheaper than the entire thing. You could create an Autococker cupseal/valve stem for the Spyder, and it'd probably work just fine.

[XSiv Force]

thats what we were thinking but werent forsure thanks bigred