Possibly the simplest of all valves is the ball valve. But despite its simplicity it is extremely effective and that is because, in many ways, it is the obvious answer to something that at one time must have had engineers racking their brains.
What is a ball valve used for? It’s for shutting off the flow of a liquid or gas within a pipe. Let’s look at the problem from the point of view of an early plumber. Some genius had invented the pipe, which enabled you to run water from A to B. That is, it enabled you to get the flow started. What hadn’t been addressed was how to stop that flow without going back to the source and disconnecting it. What was needed was a barrier that could be easily put in the way within the pipe and just as easily removed.
One possibility was a circular disc that could be turned flat across the flow or sideways so that it stood in the middle, keeping out of the way as much as possible. We still have these today and they’re known as butterfly valves. They can be very effective, but there are built-in vulnerabilities in the way the shaft is moulded through the centre of the disc, and more importantly, the fact that the disc has to be very slim.
The Night They Invented the Ball Valve
Let’s say an engineer – a talented thinker dedicated to bringing sophistication to a relatively primitive industry – applied themselves to the problem. What shape could you move easily inside a pipe? A cylindrical plug would go forwards and backwards and in theory you could twist it clockwise or anticlockwise. But it would be just that, a plug. Unless you pulled it right out again you couldn’t let the water flow.
What other shape would fit in there and provide a seal? A ball, yes, and if you drilled a hole in the ball, you could turn it sideways so the hole was hidden or align it so the hole was in the direction of the flow. The water could go through. All it would take would be a 90 degree movement, a quarter turn. Break out the champagne, guys, I think we’ve got it.
Since that glorious day, everybody in the world has benefited from the simple brilliance of the ball valve. They are in domestic plumbing systems, they’re in industrial plumbing systems, and they’re used in irrigation.
They can be used in exactly the same way to control the flow of gas, so they’re in central heating and they’re used in countless applications in factories, pumping stations and all kinds of other locations. All you see is a tap or lever that opens and closes them. Inside the housing is a ball valve.<br />The ball valve is one of the unsung heroes of the industrial world. You’ll see brass ones, stainless steel ones and manmade material ones referred to as poly because no one likes the word plastic, even if it covers a multitude of quite different materials.