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I am about to replace my 2, 3/4" thruhulls (pickups for livewell and raw water wash) and have a couple questions. I see alot of people say dont get ball valves, get seacocks. But then i see pics of the setup of a newer Yellowfin 24' that has 2 stainless ball valves (on either bronze or stainless thruhulls, couldnt tell)for the pickups and not seacocks.
My boat, a 2000 24' Vector has the original ball valves on both of the thruhulls. Why the descrepancy?
I am wanting to replace with 2, 3/4" titanium thru-hulls(for the 2 below the waterline pickups), and 2 stainless ball valves. Any prob with that setup?
__________________ If it don't matter to you, it don't matter to me...
Anybody? I know alot of you guys say, get seacocks instead of ball valves. So, why do Yellowfin and Hydra both use ball valves instead of seacocks? Is a seacock that important on a 3/4" thruhull?
__________________ If it don't matter to you, it don't matter to me...
I believe a true seacock is a one piece unit with a flange that forms the inside attachment point of the thru hull. A true seacock can be a ball valve. In a configuration where there is a thru hull that has a threaded pipe onto which a threaded ball valve or gate valve or whatever type of valve threads onto the thru hull, this is not a "seacock". A true seacock may offer more strength (i guess) than a connection via a threaded pipe. A more practical assembly is that which you describe seeing on the boats mentioned because it would allow you to replace the valve without impacting the thru hull. Contender does them this way as well. Maybe there is something in the rigging process that may make it more practical as well?
Take care to match thread type. I think most heavy duty seacocks have NPS straight on the upper end of the through hull and lower part of the HD lever ball valve( so the flange can be screwed down tight all the way), and the upper outlet of the ball valve is NPT tapered thread. Better check that though. ( That seems to be the case here: http://www.groco.net/08-scks-valves/sbv.htm
Also important, as b622r point out ,is the wide flange of the heavy duty type to spead the load on the backing "plate" - as seen in those link pics. This helps save the integrity of both the hull and the thru-hull pipe.
There is a tendency for the handle or more importantly the handle fastener to eventually break on some of the lighter ball valves used in some boats.
If using bronze , suggest getting high-quality marine like Buck Algonquin or similar fixtures , never brass or copper or cheap household (or Chinese?)bronze.
Seacocks mount to the inside of the hull w/ 3 bolts that come through from the outside of the hull(as well as the thruhull itself) this is a seacock from West Marine http://www.westmarine.com/webapp/wcs...44&ci_sku=5651
But in the pic of CaptToms Yellowfin 24' (in this thread http://outdoorsbest.zeroforum.com/zerothread?id=881479) it clearly shows 2 stainless ball valves, my 24' Vector is the same. Just curious as to why people always say dont use ball valves, use seacocks when builders of the like of yellowfin don't feel the need. The only thing i could think of is with a hole like 3/4 or 1", a seacock isnt really required, but a ball valve is sufficient. There is even a guy who posted in that thread that he needs seacocks and get rid of his current rigging, lol...
I am replacing my 3/4" thru-hulls w/ these titanium 3/4" thruhulls. Here is a pic of the threads. Titan doesnt list the thread, but will i have a prob w/ the threads on the Gem ball valve? (link at the bottom of post) http://www.titan-marine-hardware.com...thru-hulls.htm
And replacing with these Gem stainless ballvalves which looks like the 1's yellowfin uses in that thread. And Hydra used Gem products even in 2000 on my boat so i know the quality of the materials i am using is the best. http://www.gemlux.com/catalog.aspx?p...rch=BALLVALVES
__________________ If it don't matter to you, it don't matter to me...
I am replacing my 3/4" thru-hulls w/ these titanium 3/4" thruhulls. .......
Why "titanium"?
Mixing metals will lead to problems down the road. Most manufacturers use bronze for everything to avoid these problems. That's what I would do.
Also, you'll find it far easier to just replace any worn out or defective parts with the identical parts than re engineering the setup. That is unless it wasn't done right in the first place.
Mixing metals will lead to problems down the road. Most manufacturers use bronze for everything to avoid these problems. That's what I would do.
Also, you'll find it far easier to just replace any worn out or defective parts with the identical parts than re engineering the setup. That is unless it wasn't done right in the first place.
You tell me, hydra sports put ball valves, yellowfin puts ball valves, so why does everyone always say "get seacocks".
Still no answer to my question of why does everyone say "don't get ball valves, get seacocks" Even in that thread i posted, a guy says "get rid of ball valves and get seacocks" Still cant get an answer to that. Everything but...
But since you ask, why titanium? So i dont have to change out the pickup thru-hulls ever again. Just reseal them if anything and replace the valves (either seacocks or ballvalves if someone would give an answer to that part). Titanium will not react with other metals and it is not susceptable to seawater. The 3/4" are $50 apiece and i only need 2, which is far from bank breaking. I want the best material for my application, and bronze is not it. It's acceptable, but not the best.
I am not reengineering anything. I am only replacing what is already there, just with a better material. I have 2, 3/4" bronze thruhulls on there now.
Now, If i take the advice i hear all the time on this forum, which is "get rid of the ball valves and get seacocks" then i will be reengineering because i would have to put new holes for the seacocks. Thats the question that i need answered please.
__________________ If it don't matter to you, it don't matter to me...
I'd guess the pics you ref are not stainelss valves, but chrome or nickel plated bronze. I would recommend plated bronze over using stainless (or Ti) in any below the waterline application.
To your question on seacocks, ABYC requirement is any below the waterline fitting has to withstand 500 lbs of lateral force without breaking.
Take a look at any of those pics of high end builders using ball valves threaded onto a thru hull, and ask yourself if two 250 guys standing on one of these fittings will hold up. Not likely. If it fails, the boat sinks, right now.
The three bolt flanged seacocks are designed to withstand this.
Not saying this is going to happen, the thru hulls may be in a place where they cannot be stood on, or where any lateral load is unlikely, but that is the spec, and there is a reason why it's on the books.
My OPINION on the subject is this -
a true seacock is the more fail safe design because it is mounted to the hull and because one unit with the underside peice below. as mention it is designed so that if something were to hit it, it would not sheer off and create an open hole. on bigger boats sea cocks are used.
However like you mentioned, most of the top tier center console builders use thru hulls and ball valves. my opinion on the reasoning behind this is that the area that they are working in is much smaller and the ball valve combo takes up less space. in addition given the small space there is far less likely to be anything in the bildge that is big enough or traveling with enough force to sheer off a bronze fitting on the inside of the boat.
its not like an engine room on a 70' sportfish where you may have tool boxes or spare props in a space big enough to stand. yes a person can usually get too feet down into the bilde in a CC and standing on one of the fitting would probably cause it to fail, but this is not a likely scenario.
so to save space and have an easier install especially with multiple fittings the builders seem to use the thru hull and ball valve combo. I just redid mine and went with the same ball valve combo that Sea Vee had originally installed back in 1998. So i think you are pretty safe - in addition your boat is older and you are replacing what was there. Did your ball valve fail on you at any point prior?
but to totally through you off track, i have noticed that contender and sea vee have started to go to a sea cock install on boats where they are installing the sea chests. in this configuration, they have 1 larger thru hull fitting matched up to a sea cock that feeds a sea chest. from there all the livewells and SWW are fed. this set up makes sense since the 1 inflow is larger in order to feed everything and since there is only 1 inflow they have the room for the sea cock.
just as a side note - i have an extra 1.5" bronze thru hull fitting and an apollo 1.5" ball valve left over from my project that I will let go for cheap.
__________________ REMEMBER SOME PEOPLE ARE ALIVE SIMPLY BECAUSE IT IS ILLEGAL TO SHOOT THEM.
But since you ask, why titanium? So i dont have to change out the pickup thru-hulls ever again. Just reseal them if anything and replace the valves (either seacocks or ballvalves if someone would give an answer to that part). Titanium will not react with other metals and it is not susceptable to seawater. The 3/4" are $50 apiece and i only need 2, which is far from bank breaking. I want the best material for my application, and bronze is not it. It's acceptable, but not the best.
I am not reengineering anything. I am only replacing what is already there, just with a better material. I have 2, 3/4" bronze thruhulls on there now.
I only asked because I have never seen or heard of titanium through hulls or seacocks.
As far as the reengineering comment, my point was that you could replace what you have with new identical components if the original installation was OK. If "top tier" manufacturers are using through hulls and ball valves and they are holding up, I would stay with that configuration.
Are you having a problem with your through hull or ball valve or are you just "upgrading"?
Thanks GTRFred and Darb, that definitely eases my mind in that dept a bit. I mean, i wasnt closed to the idea of seacocks, but i felt they really were'nt needed but did'nt know for sure. Just was curious as to why, and space saving and they abyc standard seem like very logical answers. And on a 3/4" i should be fine w/ ball valves.
Quote:
Originally Posted by rwidman
I only asked because I have never seen or heard of titanium through hulls or seacocks.
As far as the reengineering comment, my point was that you could replace what you have with new identical components if the original installation was OK. If "top tier" manufacturers are using through hulls and ball valves and they are holding up, I would stay with that configuration.
Are you having a problem with your through hull or ball valve or are you just "upgrading"?
I am not having a prob w/ those 2 thru-hull pickups or the bv's yet. But they are original(2000) so its definitely time before i DO have a prob, and thats not the place i want a prob, lol. i have noticed the caulking peeling off around the edges of the backing nut and around the outside flange part.
Also my bilge is wayyy small, so the less im down there and the less i have to worry about those components, the better..
Did you see the weblink i posted? Its at the bottom here if you missed it. The titanium stuff is the best on the market for marine applications. They don't have titanium seacocks or bv's yet. But the titanium wont cause galvanic corrosion against the stainless anyway. They have some instances of titanium thruhulls being on commercial ships and blowboats for 30yrs and counting. I think 40% stronger and 60% lighter than steel. Most titanium stuff was invented for the aerospace industry but the price of titanium has dropped substantially in the last few years. $50 for a 3/4" thruhull isnt too expensive when you only need 2, but i couldnt do all my thruhull drains, just too much money, just the pickups. If you do all of them though, i think you can do away w/ your bonding system, because titanium is oblivious to all 3 types corrosion (galvanic, crevice, eloctrolytical). Very cool stuff that you wont ever have to replace again and is far superior to bronze or stainless. Im also going to get the titanium hose clamps for just those pickup thruhulls. The stainless 1's i have succumbed to crevice corrosion. I just want the 2 holes in the bottom with the best stuff, cause thats 1 of the places you could have the worst of problems... Thanks for the responses everyone..
It seems like the OP wants to "do the right thing". The right thing is to comply with ABYC requirement and not reinvent the specifications just because certain high end builders want to cut corners. Bronze materials, plated or unplated, are perfectly adequate for the job. There is no need for stainless, and in fact stainelss may be a step backwards if the boat is to be wet slipped.
It is true that most CC builders do not use proper seacocks. It doesn't mean it's right. It also doesn't mean your boat will sink if you don't use a seacock.
The ABYC requirment is clear, and it does not distinguish between large sportfish and small CC's- the spec is the same.
It seems like the OP wants to "do the right thing". The right thing is to comply with ABYC requirement and not reinvent the specifications just because certain high end builders want to cut corners. Bronze materials, plated or unplated, are perfectly adequate for the job. There is no need for stainless, and in fact stainelss may be a step backwards if the boat is to be wet slipped.
It is true that most CC builders do not use proper seacocks. It doesn't mean it's right. It also doesn't mean your boat will sink if you don't use a seacock.
The ABYC requirment is clear, and it does not distinguish between large sportfish and small CC's- the spec is the same.
Nickel plated, bonded, seacock on my CC.
Thats the way it should look. Very nice. What size are your thruhulls? I think that fact has alot to do w/ how much weight can be applied. I would think the smaller the hole, the more weight it could accept? Thats why the balvalves are acceptable to YF and Hydra. Because they probably could hold 500lbs.
Just think, if you have titanium thruhulls, you can get rid of all the green bonding wires, lol. Might cost ya a grand or so, lol...
__________________ If it don't matter to you, it don't matter to me...
Anybody? I know alot of you guys say, get seacocks instead of ball valves. So, why do Yellowfin and Hydra both use ball valves instead of seacocks? Is a seacock that important on a 3/4" thruhull?
Lets face it, all production boat companies are out to save money. To properly install a seacock takes more time and labor than to just use a stainless ball valve.
We have taken brand new boats and removed the thru hull / ball valve combo to replace with a proper backing block thru hull and seacock.
If its below the water line I feel that a proper seacock is a must. ABYC also states that the seacock/valve must be able to withstand a force of 500 lbs ( i think) for a certain time period, ball valves usually will not be able to make this requirement.
AND as has been stated before, thru hulls are straight thread and ball valves are pipe, Can't mix the two and form a good seal.
__________________ 24' Osprey Expedition
Volvo Penta 5.0 with Ocean Series outdrive
The sea cock has the actual valve body bolted thru the hull, and a thru hull then threaded into it. Thus it cannot break off at the hull. But what we seen in some illustations is an adaptor plate--then a length of pipe and a ball valve. This is not much better than just a thru hull and any various type of valve.
There are various types of sea cocks--some do not have the valve bolted thru the hull (better if they do). The sea cock has a tapered plug, with a bronze body (usually bronze)--but could be titanium. The plug or valve part may be a fitted or lapped bronze fitting or it may be a composition (even the entire valve may be a glass filled nylon or other synthetic plastic --which I don't like)--valve body. Some have a second handle to tighten the valve body in its tapered seat--and some have zirc fittings so they can be lubed.
As mentioned boats are built to a price point and there are ABYC (NMEA) certified boats which have ball valves and a thru hull. The titanium sounds like a good idea and corrosion or galvanic action should not damage this thru hull. I have had large boats with big thru hulls/sea cocks, and they were a devil to care for to keep them lubed and moving. Also the pipe above the valve can also break--so close the valve when leaving the boat in the water...this also prevents sinking from even a double clamped hose (which can still split)....it can be a confusing area--and use common sense.
View Product Sheet Price: $247.31 Add to Cart: 1" Hi-Speed Water Intake
GEM #: 87001
Product Category: Plumbing, Venting, and Fuel Systems / Thru-Hulls Product Material: Investment Cast Stainless Steel Body designed to be integrated into the boat hull for maximum results
These are the pickups that are in my YF. These were designed by Wylie and built for him by Gem. They are made to fit flush in the hull to reduce drag and inhance water supply flow. Acts as a water chest, and doesn't lose prime when backing up.
I am about to replace my 2, 3/4" thruhulls (pickups for livewell and raw water wash) and have a couple questions. I see alot of people say dont get ball valves, get seacocks. But then i see pics of the setup of a newer Yellowfin 24' that has 2 stainless ball valves (on either bronze or stainless thruhulls, couldnt tell)for the pickups and not seacocks.
My boat, a 2000 24' Vector has the original ball valves on both of the thruhulls. Why the descrepancy?
I am wanting to replace with 2, 3/4" titanium thru-hulls(for the 2 below the waterline pickups), and 2 stainless ball valves. Any prob with that setup?
I'm in a hurry and don\t have time to read the whole thread so what I post might be a repeat.
Thru hulls have a straight thread. Ball valves have a tapered thread. The two are not compatible. The tapered thread on the ball valve will not seal properly with the straight thread of the thru hull. Yeah, you can use some sort of thread sealant to make it seal but it is not the best thing to do
The other problem is torque. The load is not spread as good with a thru hull as it is with a seacock. When it's old and hard to close the valve, you can snap the thru hull off if too much torque is applied. This happens when you need to close the valve in an emergency, just when you don't want it to snap off.
I'd opt for a properly installed seacock. No one will ask why tou didn't install a thruu hull and ball valve.
There is a new item on the market that is a seacock without the valve. Same benefits of a seacock but you can use (and replace) the ball valve. It uses a tapered thread. Best of both workds but will cost more money up front.
Thru-hulls, ball valves and seacocks 
![](http://javascript<b></b>:bigpage("87001.jpg");)
