I’ll take my aircraft hydraulic ball valve any day over a gate valve, to me gate valves look like shit, they need to stay on the shelf at Home Depot. But to each their own, I plumbed my entire boat from scratch and it has worked and run flawlessly since it’s been finished, like the old saying goes, “if it isn’t broke, don’t fix it”. The gate valve has been around longer, and is slowly becoming obsolete. The design of the ball valve makes it vastly superior to the gate valve, and is proven to last longer and cause less problems. A ball valve utilizes a sphere with a hole in it to control flow. When the handle is turned parallel with the valve, the hole is open to flow. When the handle is turned a 1/4 turn, the sphere is also turned and the hole is now perpendicular to the valve and flow is stopped. Ball valves can almost always be operated after years of disuse and do not typically "freeze" in position. A gate valve utilizes an internal gate that moves up and down on the stem. The stem is connected to the handle which screws the gate up or down, opening and closing the gate. The gate valve has a few disadvantages. The biggest problem is that over the course of time, the stem which controls the gate may, and usually will break. This means the gate is stuck in place, and the water will either be stuck on or stuck off. Another problem is that gate valves are notorious for seizing shut after a long period of non-use. If they are able to be freed up, they will usually start to leak.
