Many posts on the "leave open" or always close 'em" discussions, but I have yet to read about anyone adding heating-system zone valves behind their seacocks. Zone valves can be held open with a 12V DC current (1A or less) and close automatically when the power is off. They can be threaded onto typical seacocks for a far-better-than-a-hoseclamp seal. Beyond the zone valve, one could use barbs and hoses, but the threaded zone valve would solve any hose-failure issues. Most have indicator switches that close when the valve is open. You could wire one to your key switch, watch for the "Open confirmed" switch to close (lighting an LED by the starter button) then fire up the inboard knowing the seawater pump is primed...all without digging around in under the aft berth. Or, how about a panel-switch that opened the valve for the head. While these zone valves are not suitable for sink drains and other "chunky" applications, I think they would work great for the head and engine water in-takes. Any thoughts?
Closing Seacocks - revisited
- Thread starter 659598
- Start date
- Status
They would have to be NC (normally closed) valves. NC means that with the power removed the position of the valves would be closed. That would also mean that if you lost power you couldn't use your head. Seems a little complicated to me.
This is a really bad idea. First, they would consume a lot of power unnecessarily. Second, have you considered what would happen if the engine cooling intake line's "zone valve" accidentally failed and closed while running the engine?? Yeah, didn't think so. 
It is generally a good idea to keep systems on a boat as simple and failure proof as possible. Adding complexity to the boat, when it comes to seacocks, is not going to be the best practice.
There are enough things that can go wrong without adding more things like this. Electricity is a scarce and precious resource on most sailboats, and wasting it to do this is not a good idea.
It is generally a good idea to keep systems on a boat as simple and failure proof as possible. Adding complexity to the boat, when it comes to seacocks, is not going to be the best practice.
There are enough things that can go wrong without adding more things like this. Electricity is a scarce and precious resource on most sailboats, and wasting it to do this is not a good idea.
Even without pointing out that they probably are not made of materials suitable for saltwater use.
There are a number of issues with using hydronic zone valves, but, the big one is dissimilar metals and the fact that stuff grows inside the valves and hoses that would prevent the ZV from seating or closing entirely. The closing mechanisms on these valves are very, very weak.
If you've done any work in the hydronics industry you'd understand just how unreliable ZV's are whether Taco, Honeywell, Automag or others. Pigs would need to be flying at mach 1 before I relied on a ZV for the safety of my boat..
Beyond that most of the commonly used zone valves eg:, Taco & Honeywell, Automag are 24 VAC not 12 VDC. Even Automag valves are 24 volt but they use 24 volts to power closed and with no power, they open. By killing the battery switch on an Automag, even if you up converted to 24V, the valve would simply open.. An open on no power design can be a benefit on a millivolt gas system in a power outage in that you still get gravity heat, or in a situation where a single valve fails in a cold climate as it prevents freeze ups because the circulator keeps circulating with an open valve.
While you might find a 12V zone valve from a Chinese supplier, Honeywell, Taco and Automag are the industry standards with Honywell and Taco holding the lions share of the distribution. Even these "big guys" are not very reliable despite use on relatively clean sealed loop systems devoid of air or marine growth which could promote corrosion or valve failures.
I personally go out of my way and spend the money and install circulators and flow checks on each zone. IMHO ZV's are a shortcut in a standard hydronic system and are rarely installed correctly or balanced correctly.
If you've done any work in the hydronics industry you'd understand just how unreliable ZV's are whether Taco, Honeywell, Automag or others. Pigs would need to be flying at mach 1 before I relied on a ZV for the safety of my boat..
Beyond that most of the commonly used zone valves eg:, Taco & Honeywell, Automag are 24 VAC not 12 VDC. Even Automag valves are 24 volt but they use 24 volts to power closed and with no power, they open. By killing the battery switch on an Automag, even if you up converted to 24V, the valve would simply open.. An open on no power design can be a benefit on a millivolt gas system in a power outage in that you still get gravity heat, or in a situation where a single valve fails in a cold climate as it prevents freeze ups because the circulator keeps circulating with an open valve.
While you might find a 12V zone valve from a Chinese supplier, Honeywell, Taco and Automag are the industry standards with Honywell and Taco holding the lions share of the distribution. Even these "big guys" are not very reliable despite use on relatively clean sealed loop systems devoid of air or marine growth which could promote corrosion or valve failures.
I personally go out of my way and spend the money and install circulators and flow checks on each zone. IMHO ZV's are a shortcut in a standard hydronic system and are rarely installed correctly or balanced correctly.
659598, I appluad your inovative thinking. Sharing ideas on this forum is what it's about.
Some of the rock stars here can be rather blunt with their criticism, but don't be discouraged, more likely the breed you are communicating with. They do generally have it correct though. simpler is better, unless money is no object.
Some of the rock stars here can be rather blunt with their criticism, but don't be discouraged, more likely the breed you are communicating with. They do generally have it correct though. simpler is better, unless money is no object.
What about a seacock built to be electric? http://madmariner.com/blogs/boat_shows/37792 . Gives the definition to B.O.A.T. "Break Out Another Thousand" .
Some of the mega yachts have motor controlled seacocks but they are HUGE money and a wiring nightmare, but when you have multiple millions.....
From the Mad Mariner link "The motors mounted on the KZ Valve are waterproof and meet ignition standards. They are available in a variety of sizes. A 1-inch seacock will cost about $875."
besides the physical size as Maine Sail said they can be a wiring nightmare, I have been on the service calls for failed zone valves and mis wired zone valves (wiring by plumbers) so on a mega yacht with an engineer on staff to go and find out why the alarm says a valve is not open yes its a great idea but not on a small sail boat
besides the physical size as Maine Sail said they can be a wiring nightmare, I have been on the service calls for failed zone valves and mis wired zone valves (wiring by plumbers) so on a mega yacht with an engineer on staff to go and find out why the alarm says a valve is not open yes its a great idea but not on a small sail boat
witz -
Rock stars? Gee, thanks, never thought we'd ever be in that category!
Blunt? He asked an engineering question.
He got engineering answers, which included reasons and explanations.
I'll stick with "the breed" and their analysis, recommendations and conclusions. Many of us actually work in the hydronics industry and do know valves and operators, as well as marine-related issues.
Less chance of something going wrong on the boat.:dance:
OK..me again, the original poster. Thank-you for your comments. I do want to add a thought or two. First, a solenoid-type 24VAC zone valve will open with 12V DC...so no need for difficult re-working of the electrical system. Of course, they are not 100% reliable, but even a leaky zone valve in combination with a failed hose clamp is a lot better than simply a failed hose clamp. A bilge pump could probably keep the boat afloat. Also, if used for a few minutes while on the head or for longer periods, but only while the motor is running, the power consumption shouldn't be a big factor. Finally, most are made of brass and all are normally (power-off) closed with manual opening levers.
That said, like most sailors, I am a K.I.S.S. guy (even though we all chose to sail, rather than just go for a nice walk on our day off). I'll keep the zone valves off my boat for now.
Thanks
That said, like most sailors, I am a K.I.S.S. guy (even though we all chose to sail, rather than just go for a nice walk on our day off). I'll keep the zone valves off my boat for now.
Thanks
Two comments:
First, I always considered Stu a rock star, and
second, as stated above "A bilge pump could probably keep the boat afloat" is a fundamentally flawed premise on which to depend on electrically operated valves even as a secondary safety device when simply closing the seacocks is full-proof - the choice is between a full-proof option and a lazy option. Is that too blunt?
First, I always considered Stu a rock star, and
second, as stated above "A bilge pump could probably keep the boat afloat" is a fundamentally flawed premise on which to depend on electrically operated valves even as a secondary safety device when simply closing the seacocks is full-proof - the choice is between a full-proof option and a lazy option. Is that too blunt?
They may do so but won't do it for very long and are designed for 24VAC. I used to represent one of the largest control makers in the hydronics industry. We invented the multiple circulator relay and the multiple zone valve control. I would not advise trying to run a ZV designed for 24V on 12V. The real issue is that a product like a Taco Gold Head draws .9A at 24 volts. Taco's have a manual lever but if you are bending over to open it then why not just open the seacock?
I don't understand how you come to that determination as there is no telling how far open or closed the valve will fail in. It may fail just barely cracked open but it may also fail totally open.
.9 amps is still quite a bit of power consumption. When we are on the boat every seacock except for the head remains open. When we leave they are all closed. For us that would be four valves needing .9 amps each to remain open.
Honeywell and Taco are power off closed, Automag the third most popular is power closed. If you need to bend over to use a manual lever on a ZV simply close or open the seacock handle.
Brass, specifically yellow brass, what most home center ball valves are made of, should not be used in below water applications. Yellow brass has a zinc content of roughly 40% and the valve body or vlave stems can be dezincified and destroyed in rather short order. Seacocks are generally always made of 85-5-5-5 bronze. Mismatching yellow brass and 85-5-5-5 bronze can be very dangerous. This is a valve from a home center that was less than a year old and the ball was totally missing as in NOT THERE. You could turn the handle and nothing happened.
If my memory serves me correctly the Taco body is silicon bronze but the valve stems and internal parts are yellow brass. The Honeywell's are brass and draw .3A @ 24V because they are not heat motor type. There are others too like Sparco, B&G & even White Rogers but they are small players in the whole scheme of the ZV market.
In reality there is nothing KISS about a sailboat..
I do agree that ZV's on a sailboat would be best left onshore to fail on hydronic heating systems..The cheapest insurance is to manually close them, inspect and replace hoses when needed and use double non-perforated high quality hose clamps such as AWAB's...
I get a little paranoid about closing my seacocks when I leave the boat. I thought of installing button switches that gets pushed on when the seacock is closed, wired to an LED light display on the nav station. Then I would hava a button there to temporarily supply the array with power to check and see if they are all closed.
Then I thought "hey, it's a 30' boat. Why don't I just go see if they are closed?"
MS -If you are a groupie, you are the groupie extraordinaire.
Then I thought "hey, it's a 30' boat. Why don't I just go see if they are closed?"
MS -If you are a groupie, you are the groupie extraordinaire.
Say "Groupie", How did you get the current to increase when you dropped the voltage? :naughty: That would only work if you changed out the guts of the ZV to maintain the wattage.
I wouldn't expect too high a reliability with half the rated wattage.
Will all common ZVs work on DC voltage? My home system runs on 24 VAC and is a thermal type, but the previous incarnation had motors.
I wouldn't expect too high a reliability with half the rated wattage.
Will all common ZVs work on DC voltage? My home system runs on 24 VAC and is a thermal type, but the previous incarnation had motors.
Good question..
The only answer is that it was early and I had not had my coffee..... Note to self, use brain more when it is early..The only ZV's I recall that actually ran on 24VDC were the older Automags. They got so much guff for not being interchangeable they have switched to using 24VAC on the newer ones.
LOL or have coffee earlier...
Good question..
Bad idea. Keep it simple and effective. Convenience or laziness is no reason to add an extra layer of uncertainty where Murphy's law can thrive. The idea of having the cooling intake being shut off on a running engine sent shivers through my spine.
- Status