Friday, January 13, 2017

Float valves : An Insight

Float Ball Valves
Float valves are machines used for filling water tanks while preventing occurrences such as overflow or back flow. In layman terms, float valves can be termed as devices that are connected to a specific water source and ensure that a constant water level is always maintained. These are commonly made from stainless steel, brass, aluminum, plastic etc. The basic working method of these valves is that these open fully when the liquid reaches a pre set low point, while closing drip tight in case the level of the liquid reaches a pre set high point. Although their working method might look simple, leading to misplaced assumptions about float valves being dispensable, the fact is that these are an essential piece of equipment in all liquid storage tanks.

Float valves are widely used in flush toilets, automated waterers for animals, auto-fillers for aquariums and many more. More often than not, these valves are ball-shaped, leading to these being referred to sometimes simply as ballcocks. Most float valves are actuated through an attached float ball, lever assembly, flat rod and do not require any external power source to function.

History of float valves

The origin of the modern float valve can be traced to references that date back to around 1790, wherein a Mexican priest and scientist named Jose Antonio de Alzate y Ramirez described an equipment that comprised of a valve which was connected to a hollow sealed float through a lever. The lever was mounted near the top of the water tank.

The above mentioned and other historical references about float valves are very similar to today's float valves when it comes to working principle. It would be apt to suggest that the materials used for manufacturing these valves might differ but the basic working method of all float valves is almost the same. The only difference that comes to mind is that while a majority of float valves do not require any external power source, some do require an external source such as manual operation, float boxes, electric motors etc.

Features of float valves
  • These are resistant to corrosion and abrasion
  • Also resistant to weathering and UV rays
  • These are long lasting and require minimal maintenance
  • A majority of float valves have optimal tolerance to chips and winding
  • These can operate under high pressure and also in very low temperatures

Some facts about float valves
 
Float valves are either single seated( tight closing) or double seated ( non tight closing). Both have their specific pros and cons and are fit for different applications
 
These valves also come in straight through or angle patterns
 
  • As stipulated by their design, these valves and either fitted horizontally or vertically
     
  • Design considerations during the design and manufacture of float valves include providing high flow rates at low head loss, specially designing the valve seat for minimizing the noise and also ensuring minimal frictional resistance etc.
     
  • Float valves should never be used for applications that are outside of their design limits. Doing so will result in problems such as premature wear, thus adversely affecting their longevity.