Standard Hydraulic Symbols

TM 5-5420-279-23

Standard Hydraulic Symbols

The hydraulic component symbols used in this manual are in accordance with International

Standard ISO 1219-1 (Fluid power systems and components - Graphic symbols and circuit

diagrams) to which reference may be made. (An extract from that standard, showing some of

those symbols used on DSB schematics is displayed in Table 5).

Table 5 Standard Hydraulic Symbols

Designation

Description

Symbol

Lines, general

Working and return lines

Control line

Leak-off line

Arrow indicates direction of flow

Compressed air line

Electrical cable

Flexible line

Unconnected line junctions

Rigid connections:

e.g. screwed, soldered

Drainage into vessel

Quick release

Coupled, with check valve

coupling

Flow rate and drop in pressure

Diaphragm valve

are largely independent of

viscosity

Appendix J Page 6