BS ISO 8625-1:2018 pdf download – Aerospace — Fluid systems — Vocabulary Part 1: General terms and definitions related to pressure
This document defines general terms relating to pressure in fluid systems used in aerospace construction.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
NOTE A graphical representation of an arbitrary pressure curve is shown in Annex A.
pressure using absolute vacuum as a reference, equal to gauge pressure plus atmospheric pressure
pressure at a specific location, temperature and time within a system or component
pressure on an object caused by its surrounding medium
absolute pressure of the atmosphere at a specific location and time
pressure acting against the specified direction of operation
minimum pressure required to overcome static friction in a component under defined conditions
burst pressure, actual
pressure at which a component bursts or shows excessive leakage due to structural failure
burst pressure, minimum
ultimate pressure, minimum
pressure up to which no burst or rupture of components is allowed
authorized pressure for official acceptance tests by authorities
pressure to which a component is charged or inflated
pressure required to control or move a component, respectively to move the component to a predefined position
pressure at which a cut‑out sequence of a component or system begins
difference in value between two pressures occurring simultaneously at different points
kinetic energy per unit volume of a fluid particle, the dynamic pressure is the total pressure minus thestatic pressure
pressure required to flush a system under defined conditions
EXAMPLE At defined flow.
measured absolute pressure minus atmospheric pressure
pressure required to maintain a system or component, or flow and/or load, at idle speed
Note 1 to entry: Also the resulting pressure when a system or component (e.g. a pump) is operated at idle speed.
pressure exerted inside a system or component
highest transient pressure which can occur in any operational condition of a system or component
minimum operating pressure
lowest pressure at which a component or system will operate with a specified performance
pressure required to maintain a system at the operating speed in the no‑load condition
theoretical average pressure at which a system or component operates
Note 1 to entry: This is usually used to classify a system or component and to derive limit pressures, such as
proof and burst pressure.
pressure at which a system or component is operated under normal operating conditions
pressure at the outlet port of a component
maximum pressure value measured during operation of a system or component within a given timeframe
pressure up to which a system is permitted to operate for safety reasons
Note 1 to entry: Only important for maintenance reasons.
pressure in portions of a component or system which results from an intended application of (external)pressure of the same or another medium, or which results from an external load
force per unit area
pressure variation, expressed graphically in relation to another value
EXAMPLE Time or flow.
difference in pressure between two points in a fluid path
variation of pressure with time, occurring arbitrarily
ratio of output pressure to input pressure
rate of change of pressure with distance in a steady‑state flow.BS ISO 8625-1 pdf download.