Hydraulic Spec Sheets: Pressure, Flow and ISO Terms Read Exactly

Fluid power sits at the intersection of mechanical engineering, materials science, and international standardization, and its documentation carries all three at once. Four things reliably break when that document is turned into data by hand.

Dual units are the norm, and a database column is not. Most hydraulic sheets present critical values twice: 250 bar (3,625 PSI), 60 L/min (15.9 GPM), operating temperature –30°C to +100°C. A person filling a catalog picks one, and which one they picked is rarely recorded. Later, somebody compares a pressure in bar against a pressure in MPa and reads a factor of ten as a product difference.

Three pressures, one column heading. Rated pressure, maximum pressure and burst pressure are three tested figures with three different meanings, and a sheet may print all three. Collapse them into a single “pressure” attribute and the catalog now states something the test report never did. The same trap sits under nominal and maximum flow, and under continuous and intermittent duty ratings.

Thread and port designations are identifiers, not descriptions. One fitting catalog can reference NPT, BSPP and BSPT, metric ISO 6149 and DIN standards, sometimes on the same page. These are not interchangeable and they are not translatable. They also belong to the dimension they qualify: a port size stored without its thread standard is a number an engineer cannot order against.

A system is assembled from sheets that do not agree with each other. A mobile power unit might combine a pump from Germany, valves from Denmark, cylinders from Italy, hoses from Turkey and a controller from the Netherlands. Every supplier names the same property differently, prints it in a different unit, and omits a different subset. Checking that the pump's maximum pressure clears the valve's rated pressure means normalizing all of it first, which is exactly the work nobody has time for.

SpecMake doesn't read a valve data sheet the way a generic PDF tool does. It reads it as a fluid power document and keeps the structure the sheet already has.

Automatic fluid power domain detection. Whether the document covers directional control valves, piston pumps, hydraulic cylinders, safety relief valves, or complete power unit assemblies, the system identifies the hydraulic domain and uses it for two things: which compliance rule sets can apply to the document, and which vocabulary a property is named in when the record is translated. “Displacement” becomes “Verdrängungsvolumen” for a pump, not “Verschiebung” from general physics.

Each parameter it finds, with its unit, its confidence and its source line where the text can be located. A rated pressure, flow rate, temperature range, port size or dimensional figure comes out as a structured field carrying the unit it was printed in, a confidence score, and, wherever the text can be located, a link to the exact line on the page. Click a linked value and the source PDF opens on that line, so a reviewer checks a figure in seconds rather than hunting through a catalog.

Standard codes are captured as identifiers, attached to their property. ISO, DIN, SAE, ANSI and ASTM references, thread and port designations, model numbers and certification marks are recognized as identifiers and kept exactly as printed, beside the value they qualify, in every export.

A dual-unit figure is read as one value, not a contradiction. A consistency pass runs over the document with no AI at all, looking for the same property stated twice with different values. It knows that “250 bar (3,625 PSI)” is one figure printed two ways rather than two conflicting claims, and that a range bound is not a second value. What it does flag is a genuine disagreement: a rated pressure on the cover that the specification table contradicts, in whichever units each of them used.

An audit checks what was captured against the source. A second pass compares the structured record with the original document and names what it finds: a pressure rating the sheet states that the extraction did not capture, a number in the record that does not match the number on the page, a section of the catalog that was skipped. Wherever the sentence that raised a finding can be quoted, the finding links straight to it.

Hydraulics is the domain where a careless compliance checker does the most damage. A standard directional control valve is not equipment for explosive atmospheres and not machinery in its own right, so scoring it against those rule sets returns a page of failures that mean nothing. The same catalog usually holds the Ex-rated version of that valve and the power unit whose sheet invokes the Machinery Regulation, and a checker working from the product class misses those. What decides is the document, not the category. Teams stop reading a report that is wrong in either direction, which is worse than not having one.

ATEX applies only when the document says so. The ATEX rule set is checked when the document indicates use in a potentially explosive atmosphere: an Ex marking, an equipment group and category, or a citation of 2014/34/EU or IECEx. A standard hydraulic valve with none of those is reported as not applicable rather than failed. Once it does apply, what gets checked is the marking itself, the equipment group and category, the gas or dust group, the temperature class and the equipment protection level. A zone is never checked as a requirement, because classifying the zone is the installer's job rather than something your data sheet declares.

The Machinery Regulation is checked when the sheet invokes it. A power unit whose documentation cites 2006/42/EC or Regulation (EU) 2023/1230, or EN ISO 12100, EN ISO 13849, EN 62061 or EN ISO 10218, is checked against that regime. A component sheet that makes no such claim is not.

What every document is checked for. Identification and traceability apply whatever the product is: does the document name its manufacturer, identify the product unambiguously, and say how to reach the manufacturer. REACH substance disclosure is checked on every document too, and CE marking documentation on every hydraulic and pneumatic sheet. These are the checks a distributor or a tender actually asks about.

The result is a compliance report you can act on rather than dismiss, and it is a documentation readiness check: it tells you what your sheet does not say, not whether the component itself is compliant.

For the OEM or system integrator, the documentation problem is a comparison problem. Does the pump's maximum pressure clear the valve's rated pressure? Does the cylinder's port match the manifold? Which of these eight suppliers left the temperature range out?

Put 3 to 10 data sheets in and SpecMake lays them out as one table, one row per specification, one column per supplier. Values are compared with their units normalized, so 350 bar, 35 MPa and 5,076 psi are read as the same pressure, and 60 L/min and 15.9 GPM as the same flow. Where the figures in a row are comparable, the highest and the lowest are marked; a specification one supplier reports and another omits is flagged as a gap; and the rows where suppliers differ are separated from the rows where they agree. A row the normalizer cannot compare, a range against a single figure or a unit it does not recognize, is left unmarked rather than ranked on the raw numbers.

The same view works on two revisions of one sheet, which is how you find what changed between last year's catalog and this one: a narrowed temperature range, a re-rated pressure, a port size that quietly moved. On that two-document view, a difference where either side was read with low confidence is marked as one to check rather than presented as fact.

The record is the deliverable. Everything below is a view of it.

Export to Excel, JSON or JSON-LD. Pressure ratings, flow rates, port sizes, temperature ranges and material grades come out as structured data ready for PIM or ERP import, with the unit and the standard reference still attached to each figure. Akeneo sync is built in and previews the field mapping against your own attributes before anything is written.

Standardize across decades and acquisitions. If your hydraulic line carries sheets from different eras and different companies, the pipeline reads them into one structure while keeping each sheet's own labels, so rated and maximum pressure stay apart instead of being guessed into one. The step where several labels land on one PIM attribute is the sync: a mapping you confirm once is remembered for later sheets in the same product family.

Keep the catalog current as the rules move. When a rule set is updated on our side, every stored record is re-scored against the new version and the products that changed status are named. Plans cover your full product catalog, with all 14 languages included.

Translation runs on the structured record rather than on the PDF. Numbers, units, thread designations and standard codes are carried across unchanged, and only the descriptive text is rendered in the target language.

Fluid power is unusual among industrial domains: it has a dedicated ISO vocabulary standard. ISO 5598 defines over 1,500 terms in English, French and German, the official terminology for hydraulic and pneumatic systems. It is why “directional control valve” is “Wegeventil” and not a literal rendering no engineer would recognize, and why a pump's displacement is “Verdrängungsvolumen”. Documentation that uses non-standard terms makes the reader translate twice, from the wrong term to the right one, which slows an evaluation and costs the document its authority. A small sample of what has to come out right: