A pressure tank is an enclosed vessel that holds liquids, gases or air at a higher pressure than the ambient pressure of the nearby environment. Pressurization is normally controlled with a series of valves and release gauges that keep contents stable without allowing them to combust or explode. There are a number of reasons why these sorts of tanks are needed, though the specifics do tend to vary based on what is being contained. Pressurized water tanks are often used in conjunction with well systems used to supply water to a home, for instance, and the extra pressure helps drive that water into the building. Industrial and commercial uses might include gas tanks for welding or oxygen tanks for patients in a hospital. Air tanks are most commonly used in conjunction with mechanical air tools or in undersea expeditions when access to air is crucial to human survival. Pressure keeps the air contained and allows for its release only when needed.
Why Pressurization May Be Important
Keeping liquids, gasses, and air under pressure is usually one of the most efficient ways of containment, but beyond this it can also help a lot when it comes to regulated dispensation. When something is kept under pressure, there is a certain threshold of energy that is captured with it, and though the underlying physics can be complicated, the basic concept isn’t: when energy is contained, it will seek a release. Slowly and intentionally releasing contents under pressure allows people to harness that energy in some useful way. A pressurized aerosol can produces a spray when depressed, for instance; pressurized water once released creates a forceful expression in showers and sinks throughout a home.
There are many different types of pressure tanks. They come in many shapes and sizes, and have a range of different intended purposes; some are for individual use or use in the home wheeas others are almost exclusively manufactured for industry. What they all have in common, though, is their general goal of keeping something contained such that it can be selectively and intentionally released, usually in small amounts. Pressurization usually means that simply opening a valve or gaining access to the contents won’t release it all the way opening a regular lid could.
Use for Water
There are two basic models when it comes to pressurized water tanks. The traditional pressurized tank holds water at a pre-determined level leaving space for some air at the top. A newer style includes a bladder that is constructed of rubber. This bladder is located inside the tank and holds the water. Air inside the tank, but outside of the bladder works to create pressure.
In the home, these are perhaps most frequently used for well-water applications. The tank will pump water out of the ground and hold it inside the tank until it is needed for use. When a faucet is turned on, water evacuates the tank and enters the water lines leading up to the faucet. The pump senses that the water in the tank has reduced, and the tank starts pumping to refill itself. When the water in tank reaches normal levels and regains its normal pressure level, the pump will turn off.
A common problem with pressurized water tanks has to do with overrunning the pump. This is evident when the pump continuously turns on and off after running for a short time. In a bladderless tank, this will occur when the air space in the tank has reduced. Air can be added to the tank with an air compressor through the top opening to return the balance of air and water to proper levels.
Gas Tanks
High pressure gas tanks have many uses. Propane and natural gas may each be used for household heating and also for operating a gas grill. Helium is used for welding and also for blowing up balloons. Oxyacetylene, argon, carbon dioxide, oxygen, nitrogen and hydrogen gases are all used in different forms of welding. Pressurized oxygen is also used for patients at home or in the hospital to improve air quality for more efficient breathing, and is also common in scuba diving and other undersea explorations.
Pressurized Air
Pressurized air tanks are frequently used to power air tools. The most common uses are for loosening and tightening lug nuts on a tire to be changed and using an impact wrench to obtain a certain amount of pressure on a part. Blowers to blow pressurized air are sometimes also used.
Safety Mechanisms
As a safety measure, pressure tanks will typically begin to leak their contents if they become unstable. In most cases this is a better alternative to the tank bursting or exploding. To be safe all types of pressure tanks are typically given this kind of safety mechanism. Depending on the contents, they may also have backup valves and control gauges to prevent accidental spillage or release.