Frank,
No, the wash from venting, etc, keeps the unit clean and with that much bearing surface, small amounts of grit won't matter. It's the design I'm building as we speak. I've got a couple of tricks from the old days to make it easier for maintenance, and cheaper to build. The pistons ought to be here this week upcoming, and the other bits are coming out of the machine shop next week as well. Now, if the welder is cooperative, we should be in business shortly. I'll take some pics as the pieces get done, do a sketch and then try to figure out how to download all this to Jon, who tells me I'm doing a white paper. (I thought it was a valve!!!).
Vance
-----Original Message-----
From: ShellyDalg@aol.com
To: personal_submersibles@psubs.org
Sent: Sat, 17 Jan 2009 11:49 am
Subject: Re: [PSUBS-MAILIST] MBT valve
Brent. If the gasket is on the top, and the piston/disk comes up against it, sand won't collect on the flat/smooth disk. Frank D.