In
mechanics
Mechanics () is the area of physics concerned with the relationships between force, matter, and motion among Physical object, physical objects. Forces applied to objects may result in Displacement (vector), displacements, which are changes of ...
, a diaphragm is a sheet of a semi-flexible material anchored at its periphery and most often round in shape. It serves either as a barrier between two chambers, moving slightly up into one chamber or down into the other depending on differences in
pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...
, or as a device that vibrates when certain frequencies are applied to it.
A
diaphragm pump uses a diaphragm to
pump
A pump is a device that moves fluids (liquids or gases), or sometimes Slurry, slurries, by mechanical action, typically converted from electrical energy into hydraulic or pneumatic energy.
Mechanical pumps serve in a wide range of application ...
a
fluid
In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...
. A typical design is to have air on one side constantly vary in pressure, with fluid on the other side. The increase and decrease in volume caused by the action of the diaphragm alternately forces fluid out the chamber and draws more fluid in from its source. The action of the diaphragm is very similar to the action of a
plunger with the exception that a diaphragm responds to changes in pressure rather than the mechanical force of the shaft.
A diaphragm
pressure tank is a tank which has pressurant sealed inside on one side of the diaphragm. It is favored in certain applications due to its high durability and reliability. This comes with a downside, as the vessel needs to be replaced in the case of a rupture of the diaphragm.
Diaphragm tanks are used to store
hypergolic propellant aboard space probes and various other spacecraft.
Pressure regulators use diaphragms as part of their design. Most uses of compressed gasses, for example, in
gas welding and
scuba diving rely on regulators to deliver their gas output at appropriate pressures. Automotive
fuel
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work (physics), work. The concept was originally applied solely to those materials capable of releasing chem ...
systems frequently require fuel-pressure regulators; this is true of many
fuel injection
Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of a fuel injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines.
All c ...
systems as well as in vehicles fueled with
liquefied petroleum gas
Liquefied petroleum gas, also referred to as liquid petroleum gas (LPG or LP gas), is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, Butane, ''n''-butane and isobutane. It can also contain some ...
(
autogas) and
compressed natural gas.
See also
*
Gas engine
*
Hybrid vehicle
References
Mechanics.
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