Hydraulics Glossary: S

Home » Technical Knowledge Hub » The Ultimate Hydraulics Glossary of Terms » Hydraulics Glossary Jargon Terminology S

A glossary of the key terms you may encounter when working with hydraulic systems. Introducing the letter 'S'…

SAE PORT:
A threaded hole and stud system used to attach fittings to a hydraulic component or manifold. Sealed with an ‘o’-ring or gasket.
SAFETY FACTOR:
The measure or ratio of burst pressure to rated pressure under specified static pressure and temperature conditions. See also under BURST PRESSURE.
SCRAPER RING:
A synthetic or metal ring fitted to the shaft of a cylinder to remove particles from the shaft thus preventing them from entering the cylinder seal chamber.
SEAL:
A device which prevents or controls the escape or passage of hydraulic fluid.
SEQUENCE:
The order of a series of operations or movements. To divert flow to achieve a subsequent operation or movement.
A hydraulic control valve that allows hydraulic fluid to flow into another area of the hydraulic system once a critical pressure has been achieved. A valve that is normally closed or normally open and changes to the opposite state when pilot pressure is applied to its spring chamber at a pre-set pressure level. Normally used to initiate a secondary set of operations in a system, based on application of the pilot signal.
A type of electronic system used for finite, analogue control of a function.
A hydraulic valve that modulates output as a function of an input command.
The portion of a fitting inserted into the bore of a hose.
The rate at which adjacent layers of fluid move with respect to each other, usually expressed as reciprocal seconds.

It’s all about YOU. Whether it’s a small one-off job, or an enduring relationship delivering complex hydraulic services, we want you to feel delighted that you have found us.

Testimonials
The frictional force overcome by sliding one layer of fluid along another, as in any fluid flow.
Other nomenclature “valve shield”. Protects valving from high velocity flow, preventing flow checking. Used primarily on agricultural interchange quick-action couplings.
Sudden extreme pressure increases within a hydraulic system.
A valve with three ports and a common ball or spool check valve. When flow is applied at either of the two inlet ports, the third or output port receives flow from the higher pressure inlet port.
A device for reducing gas flow noise. Noise is decreased by tuned resonant control of gas expansion.
Fine particles of debris. Usually found in vessels or chambers with limited, if any, circulation, e.g. the bottom of a reservoir or tank.
A hydraulic actuator that directs energy in one direction.
Other nomenclature “one-way sleeve”. Making a connection requires manually pushing the sleeve backward or pulling the body forward when mounted in a breakaway clamp, inserting the male tip, then allowing the sleeve to return to its original position. Allows pull-to-disconnect convenience when the coupling is mounted in a breakaway clamp. Sleeve Lock Prevents accidental disconnection. An arrangement which provides an additional lock which must be actuated prior to the retraction of the locking sleeve.
The external part of a hose fitting, often used to describe screw-together reusable fittings.
A coil of (usually copper) metallic wire, wound around a bobbin to magnetise the bobbin and produce linear motion of a companion spool when electricity is applied.

We are the first choice for customers in over 130 countries worldwide, supplying a vast selection of hydraulic brands and components.
You are guaranteed impartial, technical advice and optimal solutions. Every time.

contact us
Occurs upon disconnection of the quick-action coupling. This is the fluid trapped between the mating seal and the valve seal of the mating halves.
A term loosely applied to almost any moving cylindrically shaped part of a hydraulic component which moves to direct flow through the component.
A hydraulic valve that controls the direction of hydraulic fluid flow. A spool valve consists of cylindrical spools that alternately block and open channels in the hydraulic system.
A hydraulic component used to store hydraulic fluid. The spring-loaded hydraulic accumulator increases and relieves pressure through the use of a spring-loaded piston.
The ability of a system to maintain control when subjected to severe outside disturbances.
How a control system, or an individual component, operates under fixed conditions.
A measurement of pressure that exists when no fluid flow exists in a passage. The static head is normally expressed in feet of water.
A series of wire or fabric meshes bonded together by caps or perforated cylinders and fitted into hydraulic system passages to strain particles from fluid passed through the passage.
The length of travel of a piston or plunger. To change the displacement of a variable displacement pump or motor.
A metal base or auxiliary ported plate for mounting hydraulic components.

We’re in whatever market you’re in; great knowledge and service have no limits…

Our markets
A passage that leads from a reservoir or tank to the inlet port of a pump.
A reservoir.
To replenish a hydraulic system above atmospheric pressure.
Surface-active agent that reduces inter-facial tension of a liquid.
A transient, short-term rise of flow or pressure over the normal expected working pressure.
A flat, angled component of a hydraulic piston pump that moves the pistons when rotated.
A digital device which closes or opens a discrete set of contacts at a pre-set condition.
A connector or fitting with seals or o-rings that allow partial rotation while passing a fluid path through a sealed internal passage.
A hydraulic oil (fluid) made from a synthetic base and manufactured to specified characteristics. A synthetic fluid will not normally combust if heated to a specific temperature.
See also under OPERATING PRESSURE.

We’re a hydraulics ‘hub’, offering thousands of possibilities… how can we help?

contact us
Return to the ultimate hydraulics glossary