In hydraulic systems, a fuse is a component which prevents the sudden loss of hydraulic fluid pressure. It is a safety feature, designed to allow systems to continue operating, or at least to not fail catastrophically, in the event of a system breach. Table of Hydraulics and Hydrostatics, from the 1728 Cyclopaedia. ... Hydraulic fluids are a large group of liquids made of many kinds of chemicals. ... Fluid pressure is the pressure on an object submerged in a fluid, such as water. ...

The term "fuse" is used here in analogy with electrical fuses which perform a similar function. 200 A Industrial fuse. ...

Hydraulic systems rely on high pressures (usually over 7000 kPa) to work properly. If a hydraulic system loses fluid pressure, it will become inoperative and components such as actuators may collapse. Some believe that this is an undesirable condition in life-critical systems such as aircraft or heavy machinery. Hydraulic fuses help guard against catastrophic failure of a hydraulic system (for instance, by line breakage or component failure) by automatically isolating the defective branch. Wikipedia does not yet have an article with this exact name. ... A three-dimensional actuator modelled using elastica theory. ... A life-critical system or safety-critical system is a system whose failure or malfunction may result in: death or serious injury to people, or loss or severe damage to equipment or environmental harm. ...

When a hydraulic system is damaged, there is generally a rapid flow of hydraulic fluid towards the breach. Most hydraulic fuses detect this flow and seal themselves if the flow exceeds a predetermined limit. There are many different fuse designs but most involve a passive spring-controlled mechanism which closes when the pressure differential across the fuse becomes excessive.

There are two types of hydraulic fuses. The first one acts like a pressure relief valve, venting in case of a pressure surge. The second is more or less like a check valve. The only difference is a check valve is in place to prevent upstream fluid from coming back and venting out. A fuse is in place before the venting area and stops fluid from venting forward of it. Relief Valve A relief valve opens to release excess pressure when the pressure is too high to protect the vessel or other equipment from overpressurization. ... this siamese clappered inlet allows one or two inputs into a deluge gun A check valve is a mechanical device, a valve, that normally allows fluid or gas to flow through it in only one direction. ...

Hydraulic fuses are not a perfect solution to fluid loss. They will probably be ineffective against slow, seeping loss of hydraulic fluid, and they may be unable to prevent fluid loss in the event of a catastrophic system failure involving multiple breaches to hydraulic lines. Also, when a fuse activates it is likely that the system will no longer function as designed.

Depending on the system, hydraulic fuses may reset automatically after a delay, or may require manual re-opening.

In the design of a spillway for a dam, a fuse plug is a water retaining structure designed to wash out in a controlled fashion if the main dam is in danger of overtopping due to flood, and if the normal spillway channel is insufficient to control the over topping. Spillway of Llyn Brianne dam in Wales A Spillway is a structure used to provide for the controlled release of flood flows from a dam or levee into a downstream area, typically being the river that has been dammed. ... This article or section does not adequately cite its references or sources. ...

See also

• Relief valve
• Safety valve
• Fuse for the other meanings of the word.