Sean and all,I m looking at your first pics in the thread where the more elastic material, the PEEK, is on the seat, not the valve. That looks very nice. Is this the valve you mentioned in the other thread that needs to get up above 1500 psi to seal?You have shown that the PEEK is harder than the Delrin, and takes more force to seal. But then becasue it is harder, it opens more easily and gives better efficiency. So this really begs the question:What does it take to make a metal-to-metal seat work?The loading on the valve margin in "pounds per lineal inch" increases by the square of the increase in seat diameter.Your valve has a .310 throat and lets say a .140 stem. At 2500 psi, that is 154 pounds per lineal inch of valve margin (circumference). That 154 lbs/in seals the Peek just fine, without compressing it much at all.Now lets go to a .45 throat valve with a .156 stem and at the same 2500 psi, the loading at the margin increases to 247 pounds per lineal inch. I know that will seal the PEEK just fine, but might it also seal a lapped aluminum seat?The reason I am asking is that I have been working with a big valve that seems to be taking too much hammer force to crack open. Bob and I have emailed about the seemingly excessive force required and this seems like a possible reason. It now makes sense that as the valve's throat dia increases, the seat hardness must also increase.Any thoughts, please?thanks,Lloyd
I have one other thought which just came to me.... If the PEEK is allowing us to decrease hammer strike for a given power level.... then if may be that the hammer is less likely to bounce hard enough to reopen the valve.... and that in itself could increase the efficiency....Bob