Valve stem

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Replacing a valve stem. ImageerMedia-70.jpg
Replacing a valve stem.

A valve stem is a self-contained valve that opens to admit gas to a chamber (such as air to inflate a tire), [1] and is then automatically closed and kept sealed by the pressure in the chamber, or a spring, [2] [3] or both, to prevent the gas from escaping. [4]

Contents

There are many types of valves, and they are most commonly used on automobile, motorcycle, and bicycle tires, but also for many other applications. The most common type is the Schrader valve, but some road bicycles with skinny tires instead use the Presta valve. [5] [6] [7] [8]

Schrader

Schrader valve stem Schrader-ventil.jpg
Schrader valve stem

Schrader valves consist of a valve stem into which a poppet valve is threaded with a spring attached. They are used on virtually all automobile and motorbike tires and on wider-rimmed bicycle tires. In addition to tires, Schrader valves of varying diameters are used in refrigeration and air conditioning systems, plumbing, engine fuel injection, suspension systems, and SCUBA regulators, allowing the user to remove and attach a hose while in use. The Schrader valves in the fuel injector rail of many automobiles are used as a quick and easy point to check fuel pressure or connect an injector cleaner cartridge. [9] [10] [11] [12] [13] [14] [15] [16]

Presta

Presta valve stem Presta valve close.jpg
Presta valve stem

Presta valves (also called Sclaverand valves or French valves) are normally only used on bicycles. The stem has a narrower diameter (nominally 6 mm) than the thinnest (nominally 8 mm) Schrader type, and so the bore of the hole in the rim through which the stem passes can be smaller. Has a locknut that needs to be opened to inflate/deflate. [17] [18]

Dunlop (or Woods)

Dunlop (or Woods) valve stem Dunlop valve.jpg
Dunlop (or Woods) valve stem

Dunlop valves (also called Woods valves or English valves) were the dominating bicycle valves in the European region and many other countries. As of 2021, Presta valves are just as common in these regions. Dunlop valves are still widely used especially on low to medium-priced bicycles (city and trekking bikes). [19] They can be pumped up with a Presta bicycle pump. [20]

Regina

Regina Valve stem Valve Regina avec son bouchon.jpg
Regina Valve stem

The "Regina Valve" is very similar to the Presta and mostly used in Italy. [21] [ circular reference ] The central threaded pin is so short that it does not protrude from the valve tube and therefore cannot be bent. In order to close the valve tightly, a small, loose nut is placed on this threaded rod with a diameter of only around 1.5 mm and screwed on by hand. A threaded rod is enough. By tightening the nut, the valve disc with the conical sealing body is pressed against the valve seat.

Rim drilling:⌀ 6.5 mm

Thread DIN 7756 • outside VG 6×32 •outside VG 5.2×24 at the upper end

Maximum pressure 15 bars.

Others

Many other valves are used only in certain regions or for limited purposes.

Invisible tire valves are different in design from traditional tire valves. An inflator stem is not used; instead, a removable cap on a valve stem embedded in the tire rim is fitted, with only the cap visible. When inflating the tire, the cap is first removed, typically with a coin, and then a "portable" dedicated inflator stem is screwed onto the valve stem. Through the inflator, the tire is inflated as usual.

Related Research Articles

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<span class="mw-page-title-main">Poppet valve</span> Type of valve

A poppet valve is a valve typically used to control the timing and quantity of gas or vapor flow into or out of an engine, but with many other applications.

<span class="mw-page-title-main">Bicycle wheel</span> Wheel designed for a bicycle

A bicycle wheel is a wheel, most commonly a wire wheel, designed for a bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels.

<span class="mw-page-title-main">Bicycle pump</span> Air pump used for inflating bicycle tires

A bicycle pump is a type of positive-displacement air pump specifically designed for inflating bicycle tires. It has a connection or adapter for use with one or both of the two most common types of valves used on bicycles, Schrader or Presta. A third type of valve called the Dunlop valve exists, but tubes with these valves can be filled using a Presta pump.

<span class="mw-page-title-main">Schrader valve</span> Motor vehicle and bicycle tube valve

The Schrader valve is a type of pneumatic tire valve used on virtually every motor vehicle in the world today. The Schrader company, for which it was named, was founded in 1844 by August Schrader. The original Schrader valve design was invented in 1891, and patented in the United States in 1893.

<span class="mw-page-title-main">August Schrader</span> German-American inventor (1807–1894)

August Schrader (1807–1894) was a German-American inventor and mechanic. He is known for inventing the Schrader valve.

<span class="mw-page-title-main">Hydraulic machinery</span> Type of machine that uses liquid fluid power to perform work

Hydraulic machines use liquid fluid power to perform work. Heavy construction vehicles are a common example. In this type of machine, hydraulic fluid is pumped to various hydraulic motors and hydraulic cylinders throughout the machine and becomes pressurized according to the resistance present. The fluid is controlled directly or automatically by control valves and distributed through hoses, tubes, or pipes.

<span class="mw-page-title-main">Presta valve</span> Bicycle tube valve

The Presta valve is a tire valve commonly found in high pressure road style and some mountain bicycle inner tubes. It comprises an outer valve stem and an inner valve body. A lock nut to secure the stem at the wheel rim and a valve cap may also be present.

<span class="mw-page-title-main">ISO 5775</span> International standard for labeling the size of bicycle tires and rims

ISO 5775 is an international standard for labeling the size of bicycle tires and rims. The system used was originally developed by the European Tyre and Rim Technical Organisation (ETRTO). It is designed to make tire sizing consistent and clear. It replaces overlapping informal systems that ambiguously distinguished between sizes. For example, at least 6 different "26 inch" sizes exist, and "27 inch" wheels have a larger diameter than American "28 inch" wheels. The Japanese Industrial Standards Committee also cooperates with ISO 5775. The corresponding Japanese standards are JIS D 9112 for tires and JIS D 9421 for rims.

A beadlock or bead lock is a mechanical device that secures the bead of a tire to the wheel of a vehicle. Tires and wheels are designed so that when the tire is inflated, the tire pressure pushes the bead of the tire against the inside of the wheel rim so that the tire stays on the wheel and the two rotate together. In situations where tire pressure is insufficient to hold the bead of the tire in place, a beadlock is needed.

<span class="mw-page-title-main">Hydraulic brake</span> Arrangement of braking mechanism

A hydraulic brake is an arrangement of braking mechanism which uses brake fluid, typically containing glycol ethers or diethylene glycol, to transfer pressure from the controlling mechanism to the braking mechanism.

<span class="mw-page-title-main">Flat tire</span> Deflated pneumatic tire

A flat tire is a deflated pneumatic tire, which can cause the rim of the wheel to ride on the tire tread or the ground potentially resulting in loss of control of the vehicle or irreparable damage to the tire. The most common cause of a flat tire is puncturing of the tire by a sharp object, such as a nail or pin, letting the air escape. Depending on the size of the puncture, the tire may deflate slowly or rapidly.

<span class="mw-page-title-main">Piping and plumbing fitting</span> Connecting pieces in pipe systems

A fitting or adapter is used in pipe systems to connect straight sections of pipe or tube, adapt to different sizes or shapes, and for other purposes such as regulating fluid flow. These fittings are used in plumbing to manipulate the conveyance of water, gas, or liquid waste in domestic or commercial environments, within a system of pipes or tubes.

A tubeless tire is a pneumatic tire that does not require a separate inner tube.

The Dunlop valve, is a type of pneumatic valve stem in use—mostly on inner tubes of bicycles—in many countries, including Japan, Korea, India, Pakistan, Sri Lanka, most European countries, and a number of developing countries. The Dunlop valve has a wider base than a Presta valve, similar enough in size to a Schrader valve to use identically drilled valve holes in rims, but it can be inflated with a Presta valve adapter. The inner mechanism of the valve can be replaced easily, without the need for special tools.

<span class="mw-page-title-main">Bicycle tire</span> Tire that fits on the wheel of a bicycle

A bicycle tire is a tire that fits on the wheel of a bicycle or similar vehicle. These tires may also be used on tricycles, wheelchairs, and handcycles, frequently for racing. Bicycle tires provide an important source of suspension, generate the lateral forces necessary for balancing and turning, and generate the longitudinal forces necessary for propulsion and braking. Although the use of a pneumatic tire greatly reduces rolling resistance compared to the use of a rigid wheel or solid tire, the tires are still typically the second largest source, after wind resistance, of power consumption on a level road. The modern detachable pneumatic bicycle tire contributed to the popularity and eventual dominance of the safety bicycle.

<span class="mw-page-title-main">Tire changer</span> Machine used to help tire technicians dismount and mount tires with automobile wheels

A tire changer is a machine used to help tire technicians dismount and mount tires with automobile wheels. After the wheel and tire assembly are removed from the automobile, the tire changer has all the components necessary to remove and replace the tire from the wheel. Different tire changers allow technicians to replace tires on automobiles, motorcycles and heavy-duty trucks. New tire and wheel technology has improved certain tire changers to be able to change a low profile tire or a run-flat tire.

<span class="mw-page-title-main">Outline of tires</span> Overview of and topical guide to tires

The following outline is provided as an overview of and topical guide to tires:

References

  1. ↑ García-Ramírez, Yasmany (2022). "Real Driving on Under-inflated Rear Tire on Horizontal Curves: A Road Experimental Study". Proceedings of the 8th International Conference on Vehicle Technology and Intelligent Transport Systems. SCITEPRESS - Science and Technology Publications. doi: 10.5220/0011056900003191 .
  2. ↑ "Pressure". Pressure. 2020. doi:10.5040/9781682661031.
  3. ↑ Tools for pressing. Spring plungers with helicoidal compression steel spring or gas spring, BSI British Standards, retrieved 2023-09-25
  4. ↑ Hydraulic fluid power. Pressure reducing valves, sequence valves, unloading valves, throttle valves and check valves. Mounting surfaces, BSI British Standards, retrieved 2023-09-25
  5. ↑ "Handmade Automobiles". Handmade Automobiles. 2009. doi:10.5040/9781350904057.
  6. ↑ Motorcycle Headlamps, SAE International, retrieved 2023-09-25
  7. ↑ "The Repair of Single Tube Bicycle Tires". Scientific American. 75 (5): 125–126. 1896-08-01. doi:10.1038/scientificamerican08011896-125. ISSN   0036-8733.
  8. ↑ Hydraulic fluid power. Pressure reducing valves, sequence valves, unloading valves, throttle valves and check valves. Mounting surfaces, BSI British Standards, retrieved 2023-09-25
  9. ↑ Eugene A. Sloane (1991). Sloane's Complete Book of All-terrain Bicycles. Simon and Schuster. pp. 313–. ISBN   978-0-671-67587-5.
  10. ↑ "poppet valve, n.", Oxford English Dictionary, Oxford University Press, 2023-03-02, retrieved 2023-09-25
  11. ↑ Karmakar, Sibdas; Karmakar (2022-02-16), "Diameters and Conjugate Diameters", Analytical Geometry: Two Dimensions, London: CRC Press, pp. 273–300, retrieved 2023-09-25
  12. ↑ "Air conditioning system cost", Air Conditioning, Routledge, pp. 367–373, 2014-05-09, ISBN   978-1-315-79406-8 , retrieved 2023-09-25
  13. ↑ Pressure regulators for use with medical gases, BSI British Standards, retrieved 2023-09-25
  14. ↑ "Unit 1 Welcome to Plumbing", Plumbing, Routledge, pp. 13–32, 2007-08-15, ISBN   978-0-08-055005-3 , retrieved 2023-09-25
  15. ↑ Marine Carburetors and Fuel Injection Throttle Bodies, SAE International, retrieved 2023-09-25
  16. ↑ Bauer, Wolfgang (2021-10-01), "Suspension Systems Basics", Hydropneumatic Suspension Systems, Berlin, Heidelberg: Springer Berlin Heidelberg, pp. 1–22, ISBN   978-3-662-63771-5 , retrieved 2023-09-25
  17. ↑ Christopher Wiggins (5 June 2014). Bike Repair and Maintenance. DK Publishing. pp. 16–. ISBN   978-1-61564-511-4.
  18. ↑ Hydraulic fluid power. Pressure-reducing valves, sequence valves, unloading valves, throttle valves and check valves. Mounting surfaces, BSI British Standards, retrieved 2023-09-25
  19. ↑ Hydraulic fluid power. Pressure-reducing valves, sequence valves, unloading valves, throttle valves and check valves. Mounting surfaces, BSI British Standards, retrieved 2023-09-25
  20. ↑ Sheldon Brown's Bicycle Glossary
  21. ↑ "Fahrradventil". Wikipedia DE. Retrieved 27 March 2023.
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