PVC VS. Brass Shutoff for Ballast System

(bjeremi) · (bjeremi) **Join Date: Mar 2006** 03-23-2008, 6:10 PM

Finalizing my ballast install plans and had a question. I realize from a safety stand point the brass shut-off would be better but I just wanted to see if anybody who had used PVC shut-offs after the thru-hull's had actually ever had any problems. Thanks.

(sidekicknicholas)

we had PVC but after some time became a lot harder to turn, switched to brass and it has been smooth ever since

(bjeremi) · (bjeremi) **Join Date: Mar 2006** 03-23-2008, 7:02 PM

Smoothness I can deal with being that I don't plan to operate them that much, I was more worried about cracking.

(sidekicknicholas)

we have a few brass in the boat now (all easy, one hand smooth turns) and some plastic (takes a lot of might to turn them)

Don't know for sure but I think its because they're in the engine compartment and heat up making everything tighter and a lot harder to turn.... i would go brass

(denverd1)

tried to find sched 80 pvc, but couldn't. white sched 40's been holding up for four years.

(rich_g) · (rich_g) **Join Date: May 2003** 03-24-2008, 11:38 AM

I had a Schedule 40 fitting crack right in front of the shut-off valve. Luckily I had just lowered the boat and the bilge pump kicked on, so I knew something was wrong.

(bjeremi) · (bjeremi) **Join Date: Mar 2006** 03-24-2008, 11:42 AM

Damn and I was getting confident.

(denverd1)

my setup is 2" sch 40. 1/4" thick in some places.

Rich, what diam. pipe and was there any stress on it? how long did it last?

(rich_g) · (rich_g) **Join Date: May 2003** 03-24-2008, 1:06 PM

Nacho, I think it was 1" Sched 40. This was a couple of years ago in a different boat.

There was stess on it; 90-deg elbow going into the valve which was horizontal to the hull. The bouncing must have caused a crack. Age of the fittings was not a factor (maybe 2 seasons). If you had it fully supported maybe you would be ok, but why not go with bronze / brass hardware to the Shut-off valve?

(denverd1)

cuz i don't want to rip it out and redo it! it's balanced and thicker stuff. I'll see if it flexes on dubs and go from there.

thanks

(bjeremi) · (bjeremi) **Join Date: Mar 2006** 03-24-2008, 1:16 PM

($5 VS. $250 X 3
I realize it's only money but just looking to save some.

(bjeremi) · (bjeremi) **Join Date: Mar 2006** 03-24-2008, 1:17 PM

I meant $5 VS. $25 to $250

(bkoz) · (bkoz) **Join Date: Dec 2005** 03-24-2008, 2:03 PM

Using pvc isnt a problem but I would make sure to glue everything, no threads.

(bjeremi) · (bjeremi) **Join Date: Mar 2006** 03-24-2008, 2:40 PM

Here is a cool little diagram I copied/modified. I took the original off of fly high

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(mobv) · (mobv) **Join Date: Jun 2002** 03-24-2008, 5:27 PM

USCG regulations since 2005 prohibit plastic parts below the water line. As an individual you can probably get buy with installing a pvc valve. A manufacture must install a brass through hull then a brass valve. All hose connections must have 2 hose clamps. If a plastic part breaks your boat will sink.

(billy2603) · (billy2603) **Join Date: Mar 2007** 03-25-2008, 2:53 PM

What size hoses are you running? If it is 3/4" or 1" then I think the extra money spent on brass would be worth the peace of mind. You should be able to find brass ball valves for under $25 in those sizes. Are you using brass check valves, or PVC?

Also, why not tee off of one through hull in the rear? Then you'd only need one ball valve in the rear and one in the front.

(bjeremi) · (bjeremi) **Join Date: Mar 2006** 03-25-2008, 3:33 PM

I have been able to find the brass ones for under $25 but they are all NPT. All the NPS ones I have found are pretty pricey.

(billy2603) · (billy2603) **Join Date: Mar 2007** 03-25-2008, 3:47 PM

Don't NPT seal better as long as you tighten them properly? I used them and I don't think you'd have any issues and either type would still be safer than PVC in my opinion.

I was dumb enough once to put in without one of the drain plugs in. I caught it a few minutes later, but my boat was filling up very fast. If the PVC broke and you didn't notice immediately, you could get in trouble quick. Think of it as insurance.

(bjeremi) · (bjeremi) **Join Date: Mar 2006** 03-25-2008, 3:51 PM

My issue is the brass thru-hull will be NPS while the cheaper brass shut-offs at lowes and such are NPT.

(billy2603) · (billy2603) **Join Date: Mar 2007** 03-25-2008, 4:04 PM

Well, that is a conundrum. I assume my thru-hull was tapered, because I didn't have any issue. I tee'd off the stock malibu thru-hull and haven't had any issues.

I guess all I have left is to say take back your thru-hulls and get NPT instead. Obviously if you already have them installed I'm not helping.

(chadgreg) · (chadgreg) **Join Date: Feb 2008** 03-25-2008, 10:30 PM

I am having a similar problem. My thru hull is straight threads and my valve is NPT (tapered threads) I am looking for something to adapt the 2 and I found a seacock adapter at west marine but I haven't ordered it yet.
Any other suggestions? Do they have NPT Thru Hulls?
http://www.westmarine.com/webapp/wcs/stores/servlet/producte/10001/-1/10001/269297/377%20710/0/seacock/Primary%20Search/mode%20matchallpartial/0/0?N=377%20710&Ne=0&Ntt=seacock&Ntk=Primary%20Searc h&Ntx=mode%20matchallpartial&Nao=0&Ns=0&keyword=se acock&isLTokenURL=true&storeNum=11&subdeptNum=70&c lassNum=71

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