I have been changing the sanitation hoses on my boat, and I found that the
discharge seacock didn't have a ball in it(or any other means to stop the
flow of water). I did a bit of research and found out that my so called
seacock is in fact just a ball valve mounted on a threaded through-hull with
a locknut. I assume that a true seacock would have a flange at the end that
would be used to bolt the valve through the hull once it has been treaded to
the through-hull fitting. What is acceptable standards for installation of
through hulls, is mounting a inline ball valve on a threaded through-hull
acceptable ( are the threads the same - tapered).

Brad

Brad,
That is a loaded question. What is acceptable to me, you, the Insurance Co.,
Coast Guard etc. is incredibly different. There are many standards and
practices. Some of which are down-right stupid, even within the same
organization depending on hull material (like Lloyds). In the end, common
sense should be the guide. The following considerations should be made:

Fire
Electrolysis
Vibration
Maintenance

The first problem is the hull mount. This must be substantially reinforced
so that there is no chance of bond failure and points of stress
concentrations. Make certain that the valve is mounted as close to the hull
as is possible. Second, the actual valve type and material. I prefer
stainless ball valves in the engine space, insulated electrically by nylon
spacers, tophats and washers. In all other spaces I prefer plastic, fiber
reinforced ball valves from the chemical industry. Never use gate valves,
never use brass or aluminum. If you insist on bronze, be very careful about
the electrical isolation, regardless of hull material. Make certain that you
can access these valves instantly.
Steve

"Brad" wrote in message
news:b_EHb.851065$pl3.284194@pd7tw3no...
I have been changing the sanitation hoses on my boat, and I found that the
discharge seacock didn't have a ball in it(or any other means to stop the
flow of water). I did a bit of research and found out that my so called
seacock is in fact just a ball valve mounted on a threaded through-hull
with
a locknut. I assume that a true seacock would have a flange at the end
that
would be used to bolt the valve through the hull once it has been treaded
to
the through-hull fitting. What is acceptable standards for installation of
through hulls, is mounting a inline ball valve on a threaded through-hull
acceptable ( are the threads the same - tapered).

Brad