Chris:
If, to close or open the valve, it takes several turns of the handle, it is
highly probable that it is a (shudder) GATE VALVE ! If, on the other hand,
only a 90-degree turn of the handle is required, it is most surely a (big
smile) BALL VALVE !
With Gate Valves, the handle turns a screw which operates a "gate" into -
or out of - the flow path. The problem is that the screw can (and all too
often often does) separate from the gate or the handle, due to rust, and,
even though you operate the handle as you always have, the gate doesn't open
- or shut! This only happens during a critical time, such as when you are in
a blow or need the extra 'punch' to get out of the way of a wall of steel
coming at you.
Get rid of all Gate Valves, NOW, or sooner. Also, double hose-clamp every
hose where, if one gives out, water will enter your boat.
Good Luck and Smooth Sailing.............Ed