Does anyone know of a source for marine standards? In particular, I'm seking information on what types of valves and fittings should be used for marine plumbing installations. I am assuming that there would be different standards for drinking water versus raw or waste water; pressurized versus non-pressurized; above waterline versus below waterline, etc. I've done some searching on the web but so far have come up blank. Any help would be appreciated. Thanks!
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Peggie Hall/HeadMistress
ABYC Standards
American Boat & Yacht Council has a complete set of boat systems standards, including wiring and boat piping. Boat builders follow them (most of 'em anyway) and ABYC standards, along with UL (UL has a marine code too), NFPA (National Fire Protection Association), and USCG standards are what surveyors--the good ones, anyway--use. They're not free, though...you have to buy them, and they're not cheap. Unless you're planning to rip it all out and start over including relocating thru-hulls, they're prob'ly not worth the expense. A chapter in my book (which is scheduled to be out in 3 weeks) is devoted to standards for sanitation systems. However, In a nutshell, the piping standard requires that: Hoses should be of the type rated for their intended use--potable water, fuel, exhaust, below waterline connections or above waterline only etc--and hose mfrs' specs indicate which hoses should be used for a particular application. All connections should be double clamped. All seacocks and valves should be readily accesssible. Vented loops are required in most hoses connected to below waterline through-hulls. If any hard pipe is used, it should be "soft coupled" to all rigid or fixed equipment and thru-hulls with enough hose to cushion shock and allow for flex. As for types of valves and fittings, it has much to do with common sense as any standard--mixing some metals can result in galvanic corrosion, because plastic and metal have different thermal coefficients, metal fittings in a plastic tank can result in a cracked tank, ball valves are more reliable than gate valves, etc. There's a lot of room between the minimum standard and the best quality...If I knew what you're up to, I can prob'ly advise you about what to use and how to install it.
American Boat & Yacht Council has a complete set of boat systems standards, including wiring and boat piping. Boat builders follow them (most of 'em anyway) and ABYC standards, along with UL (UL has a marine code too), NFPA (National Fire Protection Association), and USCG standards are what surveyors--the good ones, anyway--use. They're not free, though...you have to buy them, and they're not cheap. Unless you're planning to rip it all out and start over including relocating thru-hulls, they're prob'ly not worth the expense. A chapter in my book (which is scheduled to be out in 3 weeks) is devoted to standards for sanitation systems. However, In a nutshell, the piping standard requires that: Hoses should be of the type rated for their intended use--potable water, fuel, exhaust, below waterline connections or above waterline only etc--and hose mfrs' specs indicate which hoses should be used for a particular application. All connections should be double clamped. All seacocks and valves should be readily accesssible. Vented loops are required in most hoses connected to below waterline through-hulls. If any hard pipe is used, it should be "soft coupled" to all rigid or fixed equipment and thru-hulls with enough hose to cushion shock and allow for flex. As for types of valves and fittings, it has much to do with common sense as any standard--mixing some metals can result in galvanic corrosion, because plastic and metal have different thermal coefficients, metal fittings in a plastic tank can result in a cracked tank, ball valves are more reliable than gate valves, etc. There's a lot of room between the minimum standard and the best quality...If I knew what you're up to, I can prob'ly advise you about what to use and how to install it.
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Tim
Peggy, thanks and..
... what I'm up to, actually, is installing the Peggy-Hall-flush-o-matic system where you tee the head sink drain to the head inlet so you can fill the inlet with fresh water fron the sink (and some white vinegar!) to avoid that lovely rotten egg smell on the first few flushes of the week. Here are the issues though: the head inlet is teed off to the deck washdown pump, and there is 25+ feet of hose heading to the washdown system at the bow. I want to either put a check valve or a shut off valve on the line to the washdown system so that water doesn't backflow into the head inlet line. Also it seems like I'll need some way to shut off the head inlet connection to the sink drain for normal head operation. If not, won't the toilet suck the air from the drain line (path of least resistance) rather than the sea water? Lastly, the currently installed drain hose is short and very stiff and so adding a tee will be very difficult. I'd like to switch to an easier to work with type of hose for the sink drain. Bottom line is that I want all of the above shutoff valves, check valves and hoses to be to the appopriate standards. Thanks again for any advice here!
... what I'm up to, actually, is installing the Peggy-Hall-flush-o-matic system where you tee the head sink drain to the head inlet so you can fill the inlet with fresh water fron the sink (and some white vinegar!) to avoid that lovely rotten egg smell on the first few flushes of the week. Here are the issues though: the head inlet is teed off to the deck washdown pump, and there is 25+ feet of hose heading to the washdown system at the bow. I want to either put a check valve or a shut off valve on the line to the washdown system so that water doesn't backflow into the head inlet line. Also it seems like I'll need some way to shut off the head inlet connection to the sink drain for normal head operation. If not, won't the toilet suck the air from the drain line (path of least resistance) rather than the sea water? Lastly, the currently installed drain hose is short and very stiff and so adding a tee will be very difficult. I'd like to switch to an easier to work with type of hose for the sink drain. Bottom line is that I want all of the above shutoff valves, check valves and hoses to be to the appopriate standards. Thanks again for any advice here!
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Peggie Hall/HeadMistress
Without seeing the plumbing...
I think you're over-complicating it. Why would you need a valve to prevent backflow from the washdown pump from getting into the head intake line? The pump is PULLING water when it's on...backflow into the head intake is impossible. When you turn it off, any water left in the line will run downhill back out the thru-hull, not uphill to the toilet. So I TEEENK all you really need is a y-valve ahead of the tee to allow you to choose between the washdown and the sink drain. "seems like I'll need some way to shut off the head inlet connection to the sink drain for normal head operation. If not, won't the toilet suck the air from the drain line (path of least resistance) rather than the sea water?" You can handle that two ways: keep a plug in the sink except when you're using it (rarely will the head and sink be in use at the same time)...or install shutoff valve conveniently located under the sink that stays closed except when you want use the sink. "the currently installed drain hose is short and very stiff and so adding a tee will be very difficult. I'd like to switch to an easier to work with type of hose for the sink drain." Any hose rated for below waterline connection will work. "Bottom line is that I want all of the above shutoff valves, check valves and hoses to be to the appopriate standards." Just buy good quality products and read the labels to make sure they're made for your intended purpose.
I think you're over-complicating it. Why would you need a valve to prevent backflow from the washdown pump from getting into the head intake line? The pump is PULLING water when it's on...backflow into the head intake is impossible. When you turn it off, any water left in the line will run downhill back out the thru-hull, not uphill to the toilet. So I TEEENK all you really need is a y-valve ahead of the tee to allow you to choose between the washdown and the sink drain. "seems like I'll need some way to shut off the head inlet connection to the sink drain for normal head operation. If not, won't the toilet suck the air from the drain line (path of least resistance) rather than the sea water?" You can handle that two ways: keep a plug in the sink except when you're using it (rarely will the head and sink be in use at the same time)...or install shutoff valve conveniently located under the sink that stays closed except when you want use the sink. "the currently installed drain hose is short and very stiff and so adding a tee will be very difficult. I'd like to switch to an easier to work with type of hose for the sink drain." Any hose rated for below waterline connection will work. "Bottom line is that I want all of the above shutoff valves, check valves and hoses to be to the appopriate standards." Just buy good quality products and read the labels to make sure they're made for your intended purpose.
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Tim
back flow
Peggie- My concern on backflow is when I am trying to fill the head intake line with fresh water from the sink that, in the absence of a shut off, it will pull "raw" water that is sitting in the deck washdown feed into the head intake line thus creating the same problem I'm trying to eliminate (raw water left in the head inlet line). Please take a look at the attached diagram to see what I think I need to do. Thanks again for all your help, you are the best (I WILL buy your book as soonas it's available!).
Peggie- My concern on backflow is when I am trying to fill the head intake line with fresh water from the sink that, in the absence of a shut off, it will pull "raw" water that is sitting in the deck washdown feed into the head intake line thus creating the same problem I'm trying to eliminate (raw water left in the head inlet line). Please take a look at the attached diagram to see what I think I need to do. Thanks again for all your help, you are the best (I WILL buy your book as soonas it's available!).
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