Valves made in China

I need to get a recommendation on what type of hose to use on my boat going from the through hose fitting to the strainers and the to the raw water pump. I was working in my bilge the other day and decided to clean my strainers. When i went to isolate the system several valves became inoperable. I was lucky enough to get both main valves closed but one of them the the stem broke on it. After further investigation ( and several other valves failing) I discovered that all of the valves in the system were globe valves made in China. I have already gone out and bought new valves (brass groco 1/4 turn with Stainless Steel inners) but i need to replace all of the hoses in the system. Can someone point me in the right direct on the proper hose to use and any other tip that will insure that I have a safe reliable system. Thanks

For critical fittings like those, you need high quality hose and double clamps. I would only use something like Trident Wire Reinforced 250 / 100 Flex Marine Wet Exhaust and Water Hose and good quality hose clamps like AWAB clamps.

Ken

kchace said:

For critical fittings like those, you need high quality hose and double clamps. I would only use something like Trident Wire Reinforced 250 / 100 Flex Marine Wet Exhaust and Water Hose and good quality hose clamps like AWAB clamps.

Ken

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Ditto

Thanks, that is the same thing the boat yard manager said. He is going to order the correct hose for me. Just waiting in the lift to come free so I can install the new valves. I learned a good lesson by checking the valves. Ive only had the boat for about 8 months. Everything else on the boat is in great shape.

Ditto again. Trident is among the best and at the very least raw water hose should carry an SAE J2006 rating for marine wet exhaust use.

Assume you are replacing the seacocks in their entirety, with Groco flanged seacocks, and existing are not inline ball valves attached to through hull fittings, onto which you are simply screwing new valves? More on this subject here What's Below Your Waterline? - Seaworthy Magazine - BoatUS Among other things, seacock valve threads must be compatible with through hull threads. The latter are nearly always NPS or parallel, as are proper seacocks, while in line ball valves are almost always NPT.

These are threaded valves. I'm sure they are NPT. This boat was built in 1940 so I will be sure to take caution when installing the new valves to prevent cross threading or damage to the thru hull penetration. I will be glad one I get the seasick valves installed. I will be able to take my time after that.

You've gotten excellent advise here. Steve D has brought up a problem that you don't seem to understand. There are two problems with just screwing a valve on a thru-hull fitting.

First is that the threads don't really match. The thru-hull has straight threads (NPS) and the valve has tapered threads (NPT). This mismatch only allows a few threads to engage. This is an inherently weak connection.

The other problem is that there is an unsupported section of the thru-hull fitting that can break. A proper flanged seacock solves both of those problems.

Since you've already purchased the valves, I suggest you get some Groco Flanged Valve Adapters to go between your valves and the thru-hull fittings. They prevent both of the above described problems.
Groco Flanged Adapter IBVF

I would also use the Groco premade fiberglass backing blocks.
Groco Seacock Backing Block

Ok, I didn't realize what he wrote. So NPS and NPT are a mismatch. Thanks for catching that for me. So now I have to locate the proper cross over flanges. When I get off of this iPhone I will go to a real computer and locate the right stuff. Also I agree about the backing blocks. Have never seen them but I'm sure I'll find some. Thanks for the heads up.

Poppy21 said:

Ok, I didn't realize what he wrote. So NPS and NPT are a mismatch. Thanks for catching that for me. So now I have to locate the proper cross over flanges. When I get off of this iPhone I will go to a real computer and locate the right stuff. Also I agree about the backing blocks. Have never seen them but I'm sure I'll find some. Thanks for the heads up.

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You've received excellent advice about this and I'm glad to see you understand and will heed it. This thread mismatch is something that is not totally obvious. Seacocks are extremely important to get right.

Ken

Just to be sure, you said you bought brass Groco valves. I assume you mean bronze valves. Brass is totally unacceptable for thru hull applications.

silver lining1 said:

Just to be sure, you said you bought brass Groco valves. I assume you mean bronze valves. Brass is totally unacceptable for thru hull applications.

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Groco doesn't make brass valves. All of their valves and seacocks are made with 85-5-5-5 bronze or stainless.