Dutch Schematic and Machinery Terms: A Working Glossary

Technical guide · Schematic Translator · September 2026

Machinery from the Netherlands and Flanders often comes with documentation in Dutch, and on older machines the schematics, nameplates, and maintenance pages stay Dutch for the machine's whole life. The good news for a technician: the symbols on a Dutch hydraulic schematic follow ISO 1219 and read exactly like their English-language equivalents. What you need is the vocabulary printed around them.

This glossary collects the Dutch terms technicians meet most often on schematics, nameplates, and maintenance pages, with plain English equivalents. Modern Dutch industrial documentation is often bilingual, so even partial Dutch decoding goes a long way.

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

Dutch	English	Notes
de klep	valve	the general word; older texts may say ventiel
overdrukventiel / veiligheidsventiel	pressure relief valve / safety valve	limits maximum system pressure
drukreduceerklep / reduceerventiel	pressure reducing valve	limits pressure downstream
terugslagklep	check valve	one-direction flow
afsluiter / afsluitklep	shut-off valve	isolation, not control
richtingsklep / stuurklep	directional control valve	often seen with a count, e.g. 4/3 richtingsklep
proportionele klep / regelklep	proportional / control valve	continuously variable
smoorklep / drosselklep	throttle valve	flow control; with a built-in check for free return: smoorklep met terugslag

Components: pumps, cylinders, and accessories

Dutch	English	Notes
de pomp	pump
de motor	motor	electric or hydraulic
de (hydraulische) cilinder	cylinder	hydraulic or pneumatic actuator
de zuiger / de zuigerstang	piston / piston rod
het reservoir / de olietank	reservoir / oil tank
de accumulator	accumulator
de filter / het filterelement	filter / filter element
de oliekoeler	oil cooler	heat exchanger
de aansluiting	port, connection

Pressures, flow, and readings

Dutch	English
de druk	pressure
werkdruk	operating pressure
maximale druk / toelaatbare druk	maximum pressure / allowable pressure
proefdruk	test pressure
inlaatdruk / tegendruk	inlet pressure / back pressure
het debiet	flow rate
het toerental	rotational speed (rpm)
het koppel	torque
de kracht / de slag	force / stroke
de lekkage / het lekolie	leakage / case oil (case drain)
de temperatuur / de opwarming	temperature / heating (temperature rise)

Port labels on Dutch directional valves

Dutch hydraulic drawings use the same international port letters as ISO drawings: P (druk, pressure), T (tank), A and B (arbeidsaansluitingen, the working ports), X, Y, Z (stuur- or pilot connections), and L (lekaansluiting, the case drain). The letters transfer directly; the words beside them are what need translating.

Lines and connections

Dutch	English
de leiding	line, pipe
drukleiding	pressure line
retourleiding	return line
zuigleiding	suction line
stuurleiding	pilot / control line
de koppeling / de fitting	coupling / fitting

Maintenance and documentation words

Dutch	English
het onderhoud	maintenance
de reparatie	repair
de oliewissel	oil change
het filterwissel / de filterwissel	filter change
het smeerschema	lubrication schedule
de handleiding / het bedieningsvoorschrift	operating manual
het (hydraulisch) schema	schematic (hydraulic diagram)
de storing / storingszoeken	fault, malfunction / troubleshooting
veiligheidsvoorschriften	safety instructions
het instellen / afstellen	setting, adjustment / to set, adjust
controleren / de controle	to check / inspection, check
in bedrijf / uit bedrijf	running (in operation) / stopped (out of service)

Two sentence patterns cover a surprising amount of Dutch maintenance text: "elke X bedrijfsuren" (every X operating hours) and "zie de handleiding" (see the manual).

Field habit: Dutch forms long technical compounds just like German. Once you know druk (pressure) and klep (valve), you can decode drukreduceerklep (pressure reducing valve) reliably. But setpoints and interlock notes only make sense as complete sentences, so translate whole blocks, not single words.

Standards behind Dutch drawings

Dutch hydraulic schematics are drawn to NEN-EN-ISO 1219, the Dutch adoption of the ISO 1219 fluid power standard, so the symbols read like any ISO drawing. Dutch process and instrumentation documents often keep international tag letters while the surrounding words stay Dutch. 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 Dutch schematic and overlays verified English on every text block, keeping every number and symbol exactly as printed, so nothing critical gets guessed.

Have a Dutch 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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