The measurement of water pressure when the water is at rest in a closed system.

An indication of the amount of force available to operate the irrigation system. Measured with no flow in the line.

The pressure of a fluid exerted in all directions equal and opposite to the pressure tending to compress the fluid. In ventilation applications, static pressure is usually the difference between the absolute pressure in an exhaust system and atmospheric pressure, such that static pressure less than atmospheric pressure is termed "negative static pressure" and static pressure above atmospheric pressure is termed "positive static pressure." (The tendency to either burst or collapse the pipe.)

The normal force per unit area at a small hole in the wall of a duct through which a fluid is flowing.

The pressure at the valve inlet that is exerted under a "no flow" condition.

pressure measurement that is not effected by a dynamic change in the fluid flow and often used as a reference in determining differential pressure.

The pressure in pounds per square inch in a dormant or non-flowing branch line.

Refers to the pressure level (bar/kPa) when there is no flow.

The pressure which tends to burst a pipe. It is used to overcome the frictional resistance to flow through the pipe. In the case of forced-air heating systems, static pressure forces air through ducting and enclosed areas. It is usually expressed in inches of water column.

Water pressure head available at a specific location when no water is being used so that no friction loss is being encountered. Static pressure is that pressure observed on the engine inlet gauge before any water is taken from the hydrant.

The force per unit area caused by the bursting force of the air against the walls of a duct as air is moved through the duct. Frequently expressed in feet of water column.

air pressure exerted perpendicular to the direction of the flow, usually expressed in units of inches of water gauge (in WG).

The potential pressure exerted in all directions by a fluid. For a fluid in motion it is measured in the direction normal to the direction of flow.

The pressure that is independent of the kinetic energy of the fluid. Measurements are made along the surface of a pipe or the throat of a venturi. See Pressure Taps.

Pressure classified as having a small or undetectable change with time. (source: ASHRAE F97)

Pressure produced by an unmoving column of water. (also: static head) There are no friction/head losses when water is not moving, so static pressure is determined only by the vertical height of the water column. The static pressure on a 10ft. tall vertical pipe full of water would be the same as a 1000ft. long pipeline with 10ft. of head over its entire distance. See also: Dynamic pressure, Head, Head Loss, Potential Energy

A measure of potential energy per unit of volume of air. Static pressure describes the partial vacuum created in a house by exhaust fans, and goes up as the total air inlet area is decreased. It also describes the “resistance” against which the fan must work. Static pressure is usually measured in inches of water. Poultry house ventilation systems are normally designed to operate at static pressures in the 0.04 – 0.10 inch range.

Condition that exists when an equal amount of air is supplied to and exhausted from a space. At static pressure, equilibrium has been reached.

Pressure of a fluid whether in motion or at rest. It can be sensed in a small hole drilled perpendicular to and flush with the flow boundaries so as not to disturb the fluid in any way.

The pressure of water when it is not moving.

The force exerted in all directions within an air handling system. Think of it as the pressure attempting to burst the duct.

Static pressure is the normal force per unit area at a small hole in the wall of a duct or other boundary surface. The wall and boundary surfaces must be parallel to the gas stream and so located that velocity will have no effect on the measurement. It exists by virtue of the gas density and degree of compression alone.

The pressure exerted by a still liquid or gas, especially water or air.

the zero-velocity pressure at any arbitrary point within a system.

The pressure of a stationary fluid.

The static pressure in psi is the static head in feet times 0.433 psi/ft.

The force per unit area acting on the surface of a solid boundary parallel to the flow.

The measure of potential energy of a fluid.

The stable pressure in an HVAC air duct that occurs when the system is on, the fan blower is running and the pressure reaches an equilibrium point with the air flow and pressure remaining constant. Static pressure is measured by use of a manometer, in inches of water, which indicate how many inches of water the pressure can sustain at a stead state.

Water pressure head available when no flow is being permitted; does not include pressure losses.

The pressure in a water system when the water is not flowing.

The pressure exerted in all directions by a fluid. For a fluid in motion, it is measured perpendicular to the direction of flow, expressed in inches of water.

Static pressure is a term used in ventilation engineering, airspeed indication, fluid statics, hydraulics and flow measurement. It is defined as the potential pressure exerted in all directions by a fluid at rest. For a fluid in motion, static pressure is measured in a direction at right angles to the direction of flow.