Date:         Sun, 30 May 2010 18:18:52 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: fresh water pump ain't pumpin'
Comments: To: Don Hanson <dhanson928@GMAIL.COM>
In-Reply-To:  <AANLkTil39e6yZhNtr64HS0iFpiwQXP1ZpUHWytZ6TmaC@mail.gmail.c om>
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At 12:26 AM 5/30/2010, Don Hanson wrote:
>How about maybe putting compressed air in the filler hole as an alternative,
>if sucking is repugnant to you?  I bet you could just put a gas station air
>hose into the tank filler, maybe with a rag to stop the air coming right
>back out  and get enough pressure in there to start the water through the
>pump...

I'd do the numbers first, says the man who once almost blew up a
40-gallon Monel tank.

5 psi should be plenty to give some flow through a three-foot
lift.  Assuming the tank is cubical, that gives just about twelve
hundred fifty pounds total force trying to make the tank bigger
and/or rearrange the bulkheads.  Might be fine, might not -- but I'd
be thoughtful about it.

If you're going to do that sort of thing, might be safer to do it
with water, which will stop pushing when you do.  It won't change the
force numbers, but it will change how much energy gets stored in the tank.

Yours,
David