[Alberg30] Valves and through hulls

[George Dinwiddie]

Peter,

I wouldn't use PVC valves below the waterline.  PVC is not very tough
stuff.  You can get Marelon valves which are designed for such
applications, but they're not terribly cheap.  I prefer bronze, myself. 
I just replaced a Marelon valve that was getting hard to operate with a
Groco bronze seacock (ball-valve type).

BTW, did you know that seacocks have straight threads so they can be
screwed down until the flange is in contact with the backing plate of
the through-hull?  Most other valves have pipe threads which are
tapered.  Having the valve hanging up on top of the through-hull is not
as strong.

 - George

Peter Amos wrote:
> 
> In December I was in an Ace Hardware in Florida looking at PVC  ball valves.They are dark grey with a red handle rated at 400p.s.i. no metal parts,N.P.T. and very solidly built.I believe the U.S. Coastguard does not approve plastic valves as they are not fire resistant, but that aside I cannot see any reason not to replace old and corroded bronze valves with these tough corrosion free products.Perhaps in very cold conditions they would become brittle, but PVC seems to stand up to freezing temperatures in domestic plumbing situations. Nobody in the marina could come up with a logical reason not to use them,but neither was there any enthusiasm either.Perhaps boaters are naturally conservative.Has anyone used these valves or know any horror stories about them.
> Peter Amos
> Tait Tait #478
> 
> [Non-text portions of this message have been removed]
 +-----------------------------------------------------------------------------------------+
 |            The BT Global Challenge -- match racing in the Southern Ocean                |
 | http://service.bfast.com/bfast/click?bfmid=22673860&siteid=32743498&bfpage=bt_challenge |
 +-----------------------------------------------------------------------------------------+
_______________________________________________
 Public-list mailing list -- Public-list at alberg30.org
 http://www.alberg30.org/mailman/listinfo/public-list
 To unsubscribe: email to Public-list-request at alberg30.org
 Include command "unsubscribe <password>" in subject or body.
 Use command "help" for more options.

 978569819.0