French Schematic and Machinery Terms: A Working Glossary
Machinery built in France, Belgium, Switzerland, and Quebec often arrives with documentation that stays in French long after the machine crosses a border. The good news for a technician: the symbols on a French hydraulic schematic follow ISO 1219, so they read exactly like their English-language equivalents. What you need is the vocabulary printed around them: component names, pressures, ports, and the maintenance instructions that tell you what to actually do.
This glossary collects the French terms technicians meet most often on schematics, nameplates, and maintenance pages, with plain English equivalents. Accents matter for lookup: vérin and réducteur de pression will not look up correctly without them.
New to the symbols themselves? How to Read a Hydraulic Schematic walks through the ISO 1219 symbols, port labels, and a step-by-step method for tracing any circuit.
Components: valves
| French | English | Notes |
|---|---|---|
| la vanne | valve | the general word, especially for larger valves |
| limiteur de pression / soupape de sécurité | pressure relief valve / safety valve | limits maximum system pressure |
| réducteur de pression | pressure reducing valve | limits pressure downstream |
| clapet anti-retour | check valve | one-direction flow |
| vanne d'arrêt | shut-off valve | isolation, not control |
| distributeur | directional control valve | often seen with a count, e.g. distributeur 4/3 |
| valve proportionnelle | proportional valve | continuously variable |
| étrangleur / restricteur | throttle / flow restrictor | flow control; with a built-in check for free return: étranglement à clapet |
Components: pumps, cylinders, and accessories
| French | English | Notes |
|---|---|---|
| la pompe | pump | |
| le moteur | motor | electric or hydraulic |
| le vérin | cylinder | hydraulic or pneumatic actuator |
| le piston / la tige | piston / rod | |
| le réservoir / la bâche | reservoir / oil tank | bâche à huile is common for hydraulic tanks |
| l'accumulateur | accumulator | |
| le filtre | filter | |
| le refroidisseur d'huile | oil cooler | heat exchanger |
| l'orifice / les orifices | port / ports |
Pressures, flow, and readings
| French | English |
|---|---|
| la pression | pressure |
| pression de service | operating pressure |
| pression maximale | maximum pressure |
| pression d'épreuve | test pressure |
| pression d'entrée / contre-pression | inlet pressure / back pressure |
| le débit | flow rate |
| vitesse de rotation | rotational speed (rpm) |
| le couple | torque |
| la force / la course | force / stroke |
| le retour de fuites / la fuite | case drain / leakage |
| température / échauffement | temperature / heating (temperature rise) |
Port labels on French directional valves
French hydraulic drawings use the same international port letters as ISO drawings: P (pression), T (réservoir / tank return), A and B (orifices de travail, the working ports), X, Y, Z (conduites de pilotage, pilot ports), and L (retour de fuites, the case drain). The letters transfer directly; the words beside them are what need translating.
Lines and connections
| French | English |
|---|---|
| la conduite / le tuyau | line, pipe / hose |
| conduite de pression | pressure line |
| conduite de retour | return line |
| conduite d'aspiration | suction line |
| conduite de pilotage | pilot line |
| le raccord | fitting |
Maintenance and documentation words
| French | English |
|---|---|
| l'entretien / la maintenance | maintenance |
| la réparation | repair |
| la vidange | oil change (also: draining) |
| le changement de filtre | filter change |
| le plan de graissage | lubrication schedule |
| la notice d'utilisation / le manuel | operating manual |
| le schéma (hydraulique) | schematic (hydraulic diagram) |
| la panne / le dépannage | fault / troubleshooting |
| consignes de sécurité | safety instructions |
| le réglage / régler | setting / to set, adjust |
| le contrôle / contrôler | inspection, check / to check |
| marche / arrêt | run (on) / stop (off) |
Two sentence patterns cover a surprising amount of French maintenance text: "toutes les X heures de service" (every X operating hours) and "voir la notice d'utilisation" (see the operating manual).
Standards behind French drawings
French hydraulic schematics are drawn to NF EN ISO 1219, the French adoption of the ISO 1219 fluid power standard, so the symbols read like any ISO drawing. Process and instrumentation documents in French industry often keep ISA-5.1-style tag letters while the surrounding words stay French. The symbols are universal; it is the text around them that needs translating.
Translating the drawing itself
You can hold this glossary next to a drawing and work out most component names. But set pressures, alarm notes, and step-by-step procedures deserve better than word-by-word decoding. Schematic Translator photographs a French schematic and overlays verified English on every text block, keeping every number and symbol exactly as printed, so nothing critical gets guessed.
Have a French schematic on your bench? Photograph it and get verified English overlaid on the original drawing. Every pressure, part number, and symbol stays exactly as the manufacturer printed it.
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