Technical Reference

Fluid Control Glossary

Definitions for common manifold, hydraulic, pneumatic, valve, pressure, flow, sealing, machining, and industrial fluid-control terms.

Fluid-control terminology crosses several engineering disciplines. A manifold designer may work with hydraulic pressure, pneumatic flow, valve cavities, seals, CNC machining, instrumentation, filtration, and external piping within the same system.

This glossary provides concise definitions and links to deeper ManifoldJS guides where additional context is available.

Core Terms

Manifold Terminology

Manifold

A component or assembly that distributes, combines, isolates, or redirects fluid between multiple ports or circuit branches.

Manifold Block

A solid machined body containing internal passages, ports, cavities, threads, and mounting features.

Valve Manifold

A manifold containing or supporting valves that control direction, isolation, pressure, or flow.

Cross Drilling

A machining method in which holes drilled from different exterior surfaces intersect to form internal flow paths.

Port

An external connection providing access between an internal manifold passage and another system component.

Valve Cavity

A precision-machined internal feature that accepts a cartridge or other integrated valve component.

Hydraulic & Pneumatic

Fluid-Power Terminology

Hydraulics

The use of pressurized liquid to transmit energy and control mechanical equipment.

Pneumatics

The use of compressed air or another gas to transmit energy and operate machinery.

Pump

A device that moves liquid through a system and provides hydraulic or process flow.

Compressor

Equipment that increases gas pressure to supply compressed-air systems.

Cylinder

A linear actuator that uses fluid pressure against a piston to create mechanical movement.

Hydraulic Motor

A rotary actuator that converts hydraulic flow and pressure into shaft torque and rotation.

Valve Functions

Valve Terminology

Directional Control Valve

A valve that selects which passages are connected so fluid can be routed toward different parts of a circuit.

Check Valve

A valve that permits flow primarily in one direction while restricting reverse flow.

Solenoid Valve

A valve operated by an electromagnetic coil receiving an electrical control signal.

Pressure-Control Valve

A valve used to limit, reduce, sequence, unload, or otherwise manage fluid pressure.

Ball Valve

A rotary valve using a bored ball to open or close a fluid pathway.

Butterfly Valve

A rotary valve using a disc positioned inside the flow path.

Valve Manifold Selection Guide

Pressure & Flow

Fluid Engineering Terms

Pressure

Force acting over a defined area within a fluid system.

Flow Rate

The quantity of fluid moving through a system during a defined period of time.

Pressure Drop

The reduction in pressure between two points caused by resistance to fluid flow.

Fluid Velocity

The speed at which fluid travels through a passage of a particular cross-sectional area.

Backpressure

Pressure opposing the discharge or return flow from a component or circuit.

Pressure Differential

The difference in pressure measured between two points in a fluid system.

Sealing

Seal and Connection Terms

O-Ring

A circular elastomeric seal compressed within a groove between mating surfaces.

Gasket

A sealing element positioned between larger mating surfaces to control leakage.

Static Seal

A seal used between surfaces that do not intentionally move relative to each other.

Dynamic Seal

A seal operating at an interface where components move relative to one another.

Fitting

A component used to connect hoses, tubes, pipes, sensors, or other equipment to a manifold port.

Quick Disconnect

A coupling intended to permit rapid connection and separation of a fluid line.

Manufacturing

Machining and Production Terms

CNC Machining

Computer-controlled machining used to produce manifold geometry, holes, ports, cavities, and mounting features.

Deburring

Removal of unwanted sharp edges and machining remnants from a manufactured component.

Surface Finish

The physical condition or applied treatment of a manufactured surface.

Anodizing

An electrochemical process used to modify the oxide layer on aluminum surfaces.

Prototype

An early physical version used to evaluate design, manufacturing, fit, or performance.

Pressure Testing

Testing performed to evaluate pressure containment, leakage, or circuit integrity.

Measurement

Instrumentation Terms

Pressure Sensor

A device that detects fluid pressure and provides information for monitoring or control.

Pressure Transducer

A device that converts pressure into an electrical output signal.

Pressure Switch

A device that changes electrical state when pressure reaches a defined condition.

Flow Meter

An instrument used to measure movement of liquid or gas through a system.

Test Port

A connection provided specifically for temporary or permanent measurement.

Data Acquisition

Collection and recording of measurements from sensors and test equipment.

Continue Learning

Detailed Technical Guides