Valves – More Than Meets the Eye

Valves that control the flow of a liquid or gas are an obviously important part of any cleaning system.  What isn’t so obvious is the sheer number of valves that are involved and that the selection of the correct valve for a particular purpose is a little more complex than one would think.

In simple terms, a valve is a device that controls the flow of a liquid or gas through a confined path such as a pipe.  The typical house or apartment has several tens of valves scattered throughout to control the flow of water.  Every kitchen is good for at least two valves (hot and cold) while bathroom has at least 4 valves controlling the flow of water in the sink and tub or shower.  Gas appliances such as stoves and hot water heaters utilize valves to control the flow of gas.  These are some of the obvious ones.  Looking a little deeper, more and more valves keep appearing.  How about the service and safety shutoff valves for water supplies to sinks, showers, toilets, gas appliances etc?  Then there are the valves that flush and refill the toilets.  Washing machines have valves.  Hot water heating systems have, at minimum, several valves to control the flow of hot water to the various heat zones.  Refrigerators and de-humidifiers have valves to control the flow of liquid and gas refrigerant.  And don’t forget the outdoor garden faucets.  Even some windows serve as “valves” of sorts not to mention doors (although they control the flow of not only air but people and critters as well).  So valves are everywhere in the home and it’s best if I don’t even start on cars . . . I only have 500 or so words here.

Each of the valves cited above are essentially the same, controlling the flow of a liquid or gas but, in fact, they are all different.  A kitchen sink valve (faucet) not only regulates the flow of hot and cold water but also mixes them in varying proportions depending on if one intends to wash out a dirty frying pan or get a cold glass of water.  The kitchen faucet is also expected to have some aesthetic appeal.  I don’t know of many people who have two garden faucets over their kitchen sink.  Another valve, the one that flushes the toilet, has a much different job and isn’t beautiful at all.  Hidden in the bottom of the toilet tank, it must simply hold back water in the tank until the flush handle is pressed.  At that time, a huge volume of water is released very quickly to flush the contents of the toilet down the drain.  A lesser flow would not do the job – we all know that.

Although many valves in the home are manually operated, other valves, like those controlling the flow of water into the washing machine, the hot water heat controls and he valve that controls the gas to heat the oven operate in response to electrical, pneumatic or other inputs from a variety of sources.  The thermostat on the wall, for example, sends an electrical signal to a hot water heating system which triggers a sequence of events which opens the gas valve to provide the heat to heat the water and another valve which allows water to circulate through the baseboard heaters where heat is needed.

As in the above examples from the home imply, industrial and precision cleaning machines utilize numerous valves all of which must be selected to do their particular job.  The next blog will provide a little more insight into the characteristics of valves that engineers consider when selecting a valve for a particular application.

–  FJF  –

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