Plumbing is all about controlling gas, water, and much more. When it comes to controlling water, you need valves. Choosing the right valve is important so that when you encounter a difficult situation, say a toilet on the verge of overflowing, all you need to do is replace the valve, in turn, averting the crisis.
There are various ways in which valves are used in plumbing, and choosing the right valve requires some research. Fortunately, here is a guide that lists down the three most common plumbing valves in Hong Kong, providing a general overview of what they do and how they work.
These are the classic variants of valves. They are chiefly used for commercial, industrial, and institutional applications these days. Gate valves come with a "gate" that looks like a wedge or disc. When lowered, this component seals off the flow. When raised, it's retracted into the body of the valve, which means no loss of flow. This is accomplished by matching the inside diameter of the valve with the pipe it's connected to. You can control this valve by turning its wheel handle.
Gate valves in Hong Kong come in two variants - the "Open Stem and Yoke" and the "Non-Rising" type. The former comes with a handle that moves down the stem with the gate, unlike with the non-rising model. The advantage of the open stem and yoke is that you're provided an indicator of the valve's status: if the handle is down, you know it's closed. Meanwhile, the latter offers the opposite to the open stem and yoke in terms of features. Its only advantage is it provides you enough space for operation.
This variant works using a stopper, which is lowered onto a baffle, obstructing the flow. Due to space, the baffle takes up inside the valve, flow is restricted, making this type of valve not suitable for use in a full-flow situation. But it’s good for throttling and frequent operation.
Although not all valves can act as a stop, some variants like stop valves are created to block the flow of water. You'll see these behind your toilet, under your sink, and at the supplies of other fixtures. Stop valves in Hong Kong offer an easy and convenient shut-off mechanism that you will see protruding from a wall. However, due to their less flow restriction, most users prefer the standard globe valve.
Another variant of stop valves is the angle or straight stop which comes with a compression or 1/4-turn style. This is activated with a quarter turn of the handle, unlike other valves that require you to do several full rotations. Also, these valves are not designed for throttling; they are only for quick, convenient shut-off for fixtures like toilets and sinks.
Aside from plumbing valves, you might also want to check out these hoses and pipes that you can attach to these valves to drain.