My Eastbay 47 had it's outflow line from the C-12 engine to the water heater break. They had the valve hanging off a brass elbow in the engine. That hung weight combined with engine vibration eventually cause the threads on the fitting to fail. Which happened just as we were pulling into a marina to refuel. We thought it might have been an impeller until getting down in the engine compartment and discovering pink antifreeze all over the outside of the starboard engine.
Thankfully the marina had a shop and we plugged the engine side with a M14-1.5 stop-cock plug. The in-flow side also has a shut-off, which we closed.
And then we discovered the C-12 needed ELEVEN GALLONS of $20/gal Caterpillar antifreeze. It took some doing to get it poured back into the engine. Luckily I'd bought a small manual bilge pump and used that hose with a funnel. I had to have someone hold the hose/funnel into the tank while pouring the antifreeze from the opened hatch up into the salon.
All for a $2 brass elbow.
As you can see in the picture, the valves are just screwed onto threaded fittings into the engines. It's the lower one that failed. But the top one isn't really any better supported either. At least they put some protection against chafing but that's hardly enough.
Suffice to say the repair following this WILL NOT have the weight of the shut-off valves going unsupported.