PC1800 Front Shovel (1/12)

[Cooper]

I may not be the best advise but I would think a tapered pin and seat would be better. Assuming you have the capabilities to hold tolerances. And I'm sure you do . I would think the hard part would be getting the right spring. I've been wanting to make one myself and have just assumed a taper would snap and flow better than a round bearing surface. ill be following how you make out so my learning curve might not end up with more parts for the recycling bin. . Appriciate you posting your progress good or bad.

[Supermario]

This goes beyond my knowledge and experience with hydraulics. I troubleshoot and fix existing systems made by people much smarter than me, never designed or thought about making a relief but based on hyd principals the ideal relief would be a needle type seat.
Just like cylinder diameter and surface area effects the amount of power generated , so does the smaller the surface area of a relief needle valve effects the strength and sensitivity of a relief and better for that cracking pressure type operation.
Like I say.... Beyond my pay grade but that's how I see it. Nice thing is you already know flow rates and the amount your dealing with and I wonder if there's a formula out there that would tell you port size and needle dimensions to get what your looking for?

Hmmmm, i might be able to get you a pilot relief valve that runs at about 350psi come to think of it! I'll let you know next week.

[tc1cat]

Tapered pin and seat sound good but would not be my choice for a PRV. I deal with tapers every day at my real job. We make our tapers down to .000015" tolerance on diameter and .000015" tolerance on taper. These tight tolerances are used for a pressure fit of the male and female tapers. The parts are not held together by any bolt or screw just the mating of the 2 tapers under any type of pressure. A PRV using a tapered pin may lock up on you if the 2 surfaces were close to a perfect match on tapers. It takes a lot of force to get 2 matching tapers apart. Some times they don't have to be that actual close to make a very secure fit. This is in the medical field for replacement hips, shoulders, and knees.

I would use a ball bearing rather than make a tapered pin.

Just my thoughts and opinion.