|
|
31-07-2012, 09:55
|
#1
|
Registered User
Join Date: Jun 2008
Location: Annapolis, MD
Posts: 14
|
Dripping valve at AC intake thruhull
BTW, although I lurk a lot, I find this forum very useful!
I'd like some opinions, if possible. Please look at the pictures below, to get a better idea of what I am describing. I've got a sailboat that has air-con, and the AC is not original equipment. Whomever installed the thru hull and valve 11 years ago did it in a different way than I would, and this fall, when I haul, I will have it done correctly. In the meantime, the valve has just started dripping only when it is open. When I open it, about 2 oz of water come out, then it very slowly drips until I close it.
The first picture shows the thru hull with the elbow and then the gate valve. The second picture is side-view, close up of the gate valve. This is take from the "right side" of the first photo. You can barely see the drip of water on the underside of the valve. Probably a hairline crack?
This is causing me two issues:
1. If I want to run the AC, I have to open the valve and it drips, so I keep the valve closed and don't have AC.
2. I have a slight concern that the valve will fail even if it is closed. Although the "crack" or "hole" is on the "good side" of the ball valve, I don't like knowing that I have a bad valve here.
What is the experts' suggestions here on what to do NOW?
- Try and replace the valve while it is in the water?
- Remove the valve and put a plug somewhere?
- Seal it from the outside?
- Put some 5200 on the "hole" or "crack"
- Stop worrying and replace it in the fall?
Thanks in advance.
...
|
|
|
31-07-2012, 10:59
|
#2
|
Registered User
Join Date: Jun 2012
Location: Annapolis
Boat: Hylas 49
Posts: 1,121
|
Re: Dripping valve at AC intake thruhull
I'm no expert but I would plug it from the outside with a tapered plug and replace it.
|
|
|
31-07-2012, 12:04
|
#3
|
Senior Cruiser
Join Date: Oct 2007
Location: San Antonio, TX/Bocas del Toro, Panama
Boat: 1990 Macintosh 47, "Merlin"
Posts: 2,844
|
Re: Dripping valve at AC intake thruhull
A couple of thoughts/concerns:
The photo doesn't really show where the leak is. I'd be concerned that you have more than a small leak, and that possibly the whole valve/unit is going south.
If I were confident of the thru hull fitting itself, I'd plug it from the outside, then replace all of the fittings, then open it back up again.
If you are REALLY gutsy, just take the whole thing out, and replace it while in the water. Just make sure you have the right size plugs in case it turns bad, and plenty of air tanks or a hookah. Put a whole new thru hull in, with plenty of sealant that will cure in the water.
|
|
|
31-07-2012, 12:10
|
#4
|
Registered User
Join Date: Jul 2012
Location: Pensacola Fl
Boat: Heritage East 40
Posts: 199
|
Re: Dripping valve at AC intake thruhull
Dont mess with thru hulls. I would replace.
|
|
|
31-07-2012, 13:54
|
#5
|
Registered User
Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,108
|
Re: Dripping valve at AC intake thruhull
I can't see the through hull very well, but if that is a pipe-thread elbow on a straight thread through hull, then you may be a thread or two away from a major water ingress surprise.
Mark
__________________
www.svreach.com
You do not need a parachute to skydive. You only need a parachute to skydive twice.
|
|
|
31-07-2012, 15:40
|
#7
|
Registered User
Join Date: Jun 2008
Location: Annapolis, MD
Posts: 14
|
Re: Dripping valve at AC intake thruhull
Thanks for all the great comments. In remembering what it looks like from the outside, I am 99% sure that the seacock is a Groco Bronze Thru-Hull Scoop Strainer - see pic below. So plugging it in the water might not be so easy.
Also, I remember being told that ALL of the following must be below the waterline:
thru hull -> seacock -> hose -> Groko strainer -> hose -> pump
And all of this must run "uphill".
At the location of the seacock, the waterline is only about 12 inches from the hull, so I was told that is why they installed an elbow and a valve in that manor. If the seacock was placed inline with the thru hull, the top of the seacock would be too high to still plumb the Grocko strainer/hose/pump uphill from that, and still have everything be below the waterline.
Further complicating this, it looks like the thru hull might be 1.5" and the hose is much smaller, so there is a reduction fitting thrown in there. Why they put this thing into a 1.5" hole, I'll never know. Maybe they were using the existing hole from an unused transducer hole?
So ... the permanent solution, to me, is to get rid of my "crap" and get a seacock this is "low profile" enough to not end so high as to make the rest of the plumbing impossible to keep under the waterline.
Am I off base?
FYI, this is a catamaran sailboat, I do not run the AC underway
.
|
|
|
31-07-2012, 16:10
|
#8
|
Registered User
Join Date: Dec 2010
Location: Kemah, TX
Boat: Moody 42
Posts: 235
|
Re: Dripping valve at AC intake thruhull
Where is it leaking? Threads or through the valve packing? It's a ball valve by the way.
|
|
|
31-07-2012, 16:26
|
#9
|
Registered User
Join Date: Jun 2008
Location: Annapolis, MD
Posts: 14
|
Re: Dripping valve at AC intake thruhull
Quote:
Originally Posted by Sailorman375
Where is it leaking? Threads or through the valve packing? It's a ball valve by the way.
|
I added to the picture in the first post to indicate where it is dripping from. Here is the new pic.
That location appears to be the only place it is wet, so I suspect a crack. The threads and the stem are not wet. (edited based on questions from the next post).
.
|
|
|
31-07-2012, 16:28
|
#10
|
Registered User
Join Date: May 2011
Location: Miami Florida
Boat: Ellis Flybridge 28
Posts: 4,057
|
Re: Dripping valve at AC intake thruhull
I think you need to figure out where the water is coming from. If something is cracked then it becomes urgent to replace it. If it's just leaking around the stem or from the threads, you might control it just by tightening things up.
I agree with the folks that don't like this set up and would replace it with a real flanged seacock as soon as practical. If you need to keep it low profile you could use a Groco Flanged adapter, street elbow, and ball valve. This is almost as good as a real seacock. It gives you a flange to fasten to the hull and avoids the problem of mating straight threads and tapered threads.
Groco Flanged Adapter IBVF
__________________
Retired from Hopkins-Carter Marine Supplies
|
|
|
31-07-2012, 18:25
|
#11
|
Registered User
Join Date: Dec 2010
Location: Kemah, TX
Boat: Moody 42
Posts: 235
|
Re: Dripping valve at AC intake thruhull
That's a rather odd place for a ball valve to be leaking (especially only when in the open position). I for one (others will disagree) don't think there is too much wrong with using a ball valve as long as there is no chance of stepping on and breaking. I know the threads are not correct, but many builders use this set up and it would be difficult to use a seacock and keep the low profile you need. I would replace the ball valve with another of the same size. Just make sure it's all bronze construction and does not have a stainless or worse, a chrome plated brass ball like Apollo. Yes it would be better to have a proper seacock, but that may not be possible with your installation. BUT...first I would dry the area and then open the valve and see if you can determine where the leak is.
|
|
|
31-07-2012, 18:29
|
#12
|
Registered User
Join Date: Dec 2010
Location: Kemah, TX
Boat: Moody 42
Posts: 235
|
Re: Dripping valve at AC intake thruhull
By the way the suggestion to use the Groco thru hull with the flanged adaptor would probably work. You would place a street elbow on the adaptor then mount the ball valve to that. This is an expensive option though, but the best.
|
|
|
31-07-2012, 18:34
|
#13
|
Registered User
Join Date: Dec 2010
Location: Kemah, TX
Boat: Moody 42
Posts: 235
|
Re: Dripping valve at AC intake thruhull
Another thought or two. I make my living selling valves for seawater service in the oil and gas industry and no major end user in my industry will use anything short of nickel aluminum bronze in seawater service. Some use only titanium. Non flowing seawater is highly corrosive. These valves however are way too expensive for boat builders, but they will last 20 years.
|
|
|
31-07-2012, 19:31
|
#14
|
Registered User
Join Date: Jan 2008
Location: Hong Kong
Boat: Custom Freya 20m
Posts: 1,020
|
Quote:
Originally Posted by Sailorman375
Another thought or two. I make my living selling valves for seawater service in the oil and gas industry and no major end user in my industry will use anything short of nickel aluminum bronze in seawater service. Some use only titanium. Non flowing seawater is highly corrosive. These valves however are way too expensive for boat builders, but they will last 20 years.
|
Got a website for the company that do these?
Thnks
|
|
|
31-07-2012, 21:33
|
#15
|
Registered User
Join Date: Dec 2010
Location: Kemah, TX
Boat: Moody 42
Posts: 235
|
Re: Dripping valve at AC intake thruhull
You can get nickel aluminum bronze ball valves, but no one makes compatible seacocks (don't want to mix metals). I have found titanium seacocks, but can't remember offhand who make them. Since the hulls of platforms are steel, they weld in intakes to a sea chest then manifold, then to valves. You can get titanium ball valves, but you talking some dollars. In small quantities you're looking at well over $500 each for an 1 1/2" valve. Blakes (UK) makes some nice seacocks with what I guess is Naval Bronze, but they could not tell me the UNS or ASTM number, but my original Blakes are over 20 years old and still work. If it were my boat and money was not an issue I'd go with the Blakes or Sparton, but again as long as you watch them the ASTM B-62 bronze you get in the States will last a good while Groco has a fairly good reputation, but have had some issues with bad product and some recalls. The Blakes are sold as a unit with the sea cock and the thru hull sold together. I think they are British thread and would not work with any of the US Brands. Neither the Sparton or the Blakes would work with the Groco flanged adaptor I don't think. So.....In your situation (requiring the 90) I'd either just get a good quality bronze ball valve with true bronze trim, or go with the Groco flanged adaptor, new thru hull and a new ball valve with the street elbow (making sure to get a bronze elbow of good quality. Watch out as many marine stores carry poor quality bronze fittings and I've even seen brass which is a no no. Don't trust anything made in China.
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|
|