[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [PSUBS-MAILIST] Soft ballast venting valve



Jim,
             right, I had an extra zero in there ! 
-----Original Message-----
From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org]On Behalf Of Jim Kocourek
Sent: Tuesday, January 06, 2009 4:32 AM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Soft ballast venting valve

Hi Brian,
 
I agree with your concept about shaft/ fitting and thats my reason for being very comfortable with it while Frank is not.
 
I have to take exception to your clearance. Mayby it's a typo, but 50 thousanths is WAY to loose for ANY O ring seal in mu opinion and extrusion is expected.
 
I will hace about 5 -10 thousandths. I do this by boring the sleeve slightly undersized then welding the sleeve in place. After welding ream to size with a propersized reamer.
 
I wish I could get tighter, but doing the reaming freehand that's the best result I can get.
 
I am also using a Block V seal which I feel is better than an oring.
 
The idea ame from Gary Sluis.
 
Best Regards,
 
Jim K 
----- Original Message -----
From: Brian Cox
Sent: Tuesday, January 06, 2009 12:53 AM
Subject: RE: [PSUBS-MAILIST] Soft ballast venting valve

Hi Frank,
               
When you figure the diameter of the shaft and the diameter of the shaft fitting, that the shaft goes into, there is only a difference of like 50 thousandths of an inch.  Even if you forgot to put the O ring in that fitting, it's not like going to be Niagra falls coming into your boat.  You could probably put some bubble gum on it and the leak would stop.  You would be able to address a problem like that as soon as it occured.  The hydrolics would add too much of an extra thing for me to deal with.   I wonder if there is a way to smooth out those cast fittings so they could be polished?   I will probably put a T into my ballast vent valve inbetween the valve and the ferro body for HP air.  It would be nice to have a LP air generator for "topping off"   the ballast air so as to float yourself higher on the surface.  I seem to remember the Tang would do that to try and get maximum speed on the surface,  they would run the compressors into the ballast and the exess air coming out the bottom of the ballast would cut down on the friction against the water. giving them an extra knot per hour speed.
 
Brian
 
 
-----Original Message-----
From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org]On Behalf Of ShellyDalg@aol.com
Sent: Monday, January 05, 2009 6:38 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Soft ballast venting valve

Hi Brian. That makes good sense. Save a few bucks and go with what works. As for matching up the two materials, There's always going to be the corrosion factor to deal with. Zinc sacrificial anodes will help but not eliminate the problem. On the plus side, bronze and stainless won't "gall" when screwed together. I'm using a lot of brass bolts mated to stainless lock nuts. Although replacement of the brass will be needed sooner than stainless bolts would, at least I know I'll be able to get them apart without a big hassle. Some places I'll be using stainless bolts and brass nuts, because I need the extra shear strength of the stainless, but again, it comes apart easily after a long time in salt water.
    I too am going with the bronze valves. They are pressure rated to 600 psi, are cheap to replace, and when polished they look really good. Very "Capt. Nemo" like. Also, the highly polished surface corrodes much slower than the regular cast surface. I've got quite a few of the interior valves, unions, elbows, nipples, and related bushings and adaptors and when polished, they look really good. The HP air will be like yours, Swagelock and stainless tube.
    I haven't cut in any through-hulls yet, but those will all be stainless nipples. Then a bronze ball valve on each one where it enters the sub. Complete shut-off at every penetration if a problem develops. Even the electrical through-hulls will be valved off. I want to get all the components mounted before I start cutting in the nipples. The largest is 2 inch, while the smallest is 3/8 inch. The main ballast will all be 1 inch. Maybe a little slow to submerge but I don't expect that to be a problem.
    You said you're using rod linkage to operate your valves? Wouldn't a small hydraulic cylinder work just as well?
    When the weather gets a little better, I'll cruise down on my bike for a visit and a cold beer. Frank D.