A flow limiter or flow restrictor is a device to restrict the flow of 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 ...

, in general a

gas Gas is a state of matter that has neither a fixed volume nor a fixed shape and is a compressible fluid. A ''pure gas'' is made up of individual atoms (e.g. a noble gas like neon) or molecules of either a single type of atom ( elements such as ...

or a

liquid Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...

. Some designs use single stage or multi-stage

orifice plate An orifice plate is a device used for measuring flow rate, reducing pressure or restricting flow (in the latter two cases it is often called a '). Description An orifice plate is a thin plate with a hole in it, which is usually placed in a pipe. ...

s to handle high and low flow rates. Flow limiters are often used in manufacturing plants as well as

household A household consists of one or more persons who live in the same dwelling. It may be of a single family or another type of person group. The household is the basic unit of analysis in many social, microeconomic and government models, and is im ...

s. Safety is usually the main purpose of using a flow limiter. An example is manufacturing facilities and laboratories using flow limiters to prevent injury or death from noxious gases that are in use. The flow limiter prevents gases from causing injury or death by reducing its cross-sectional area where gas flows.

Uses

* Reduce flow of fluid (velocity) through a system, e.g. to reduce water usage in a shower * Reduce the amount of gas passing through a system * Reduce pressure in a system * Applications in medical instrumentation * As a

safety valve A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve (PRV), which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds ...

to provide limited flow after closing in the event of a broken

hose A hose is a flexible hollow tube or pipe designed to carry fluids from one location to another, often from a faucet or hydrant. Early hoses were made of leather, although modern hoses are typically made of rubber, canvas, and helically wound w ...

. (See '' Hydraulic fuse'').

Specifications

*Orifice diameter *Flow tolerance *Media temperature *Maximum flow rate for liquid or gas *Maximum pressure

Design

Flow limiters are designed with the intent of reducing the cross-section area with a plate and a laser drill is used to create a small hole. The diameter of the hole will vary based on the flow rate, inlet pressure, and outlet pressure. The design can also be created with drilled orifices with threaded ends. Another flow limiter design option is the use of porous media. This design is created with hundreds of pores within a central plug. The porous media design has the purpose of lowering the velocity of flow, and the lifespan is extended with lower rates of erosion. The disadvantage to the porous media design is the poor removal of particles and a drop in pressure. Debris buildup will not be a concern with the porous media flow limiter with multiple holes allowing liquid or gas to flow with ease.

Features

Flow limiters have features that may be added to expand on their applications. The device can have bidirectional flow and have increased flow control with multiple openings. Flow limiters can also be made of various materials to better improve quality and applications. The materials involve the use of metals, metal alloys, and thermoplastics. Metals like

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

and

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

are materials that have good conductivity with heat and electricity.

Stainless steel Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...

has the material strength to withstand high pressures and resists chemical corrosion. Flow limiters are also capable of being designed out of

nylon Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups. Nylons are generally brownish in color and can possess a soft texture, with some varieti ...

and fluoropolymers. For the connections to the flow limiter, there are a variety of ends featuring plain ends, pipe clamp ends, flanges, and compression fittings.Flow Orifices and Flow Restrictors Information
/ref>

References

{{Reflist Hydraulic engineering Plumbing Pneumatics

Uses

Specifications

Design

Features

See also

References