PN16 Is Not 16 Bar at Every Temperature: Publishing Valve Ratings Buyers Can Check

A valve page says “PN16” in one field and gives a high maximum temperature in another. A buyer combines the two and assumes the valve can operate at that pressure throughout the temperature range.

The page has not established that conclusion.

PN is a nominal designation. The permitted operating pressure at a particular temperature must come from the applicable rating information for the actual valve configuration. Body material, seat and seal materials, connections and other construction details can affect the usable envelope. A pressure maximum and a temperature maximum printed separately should not be read as an approved simultaneous duty point.

An English export page should help a buyer find that envelope. A nominal-class label alone leaves too much of the selection decision unstated.

What the PN number tells you

KSB's technical lexicon describes PN as an alphanumeric reference designation associated with mechanical and dimensional characteristics. The number following PN is dimensionless; it is not itself a directly measurable value or a general calculation input. The relevant component standard provides the applicable meaning and relationships. KSB: PN designation.

This explains why a universal “PN equals allowable bar” conversion is a poor way to write a valve specification. Buyers need the applicable standard, material and rating conditions. A familiar class name can help locate the right component family without completing the application assessment.

The same caution applies when a catalogue mixes different nominal-class systems. A marketing editor should not invent a conversion between PN and another rating class from a single familiar example. The correct comparison depends on the relevant standards and selected configuration.

The rating belongs to a configured item

Think of the product as a defined assembly, rather than a generic picture of a valve.

This is a proposed identification checklist, not a universal design rule or a substitute for the manufacturer's selection instructions. Its purpose is to prevent a rating from one catalogue column being attached to a different order code.

If a product page covers several seat options, it should either show their separate conditions or direct the buyer to the precise option-specific table. One broad temperature range at the top of the page can otherwise hide the limiting component.

What a real manufacturer's table demonstrates

The Swagelok 60 Series catalogue provides a useful example of how much configuration information sits behind a pressure-temperature number. Its rating section separates flow arrangements, series and materials. The accompanying notes specify construction assumptions and warn that alternative materials can have different ratings. Swagelok 60 Series catalogue, pressure-temperature section.

On page 6 of the reviewed catalogue, the specified stainless-steel two-way 62, 63, 65, W63 and W65 configuration with reinforced PTFE seats has a working-pressure entry of 2,200 psig at the listed low-temperature range through 100°F, and 330 psig at 400°F. Those entries belong to that column and its construction notes. They are not PN16 ratings, and they do not describe every 60 Series valve.

The example is useful because it makes the reading method visible: find the exact configuration, follow the temperature row, then read the notes. Extracting the largest pressure and largest temperature from separate parts of a catalogue would discard the relationship that the table was built to express.

This article does not reproduce the full table or approve an application. Buyers should consult the current manufacturer information for the actual order code, including any restrictions that are not captured by those two entries.

Four questions that an isolated rating cannot answer

Does the body meet the duty while the seat does not? A body rating does not establish the full assembled valve's suitability. The selected seating and sealing arrangement needs its own applicable limits.

Does the pressure mean line pressure or differential pressure? A buyer may be discussing the pressure within the system, the difference across the valve or an actuator's ability to operate under a given condition. The page should name the quantity rather than placing one unexplained “maximum pressure” beside the product image.

Is the quoted value an operating rating or a test condition? A pressure test has a defined method, medium, duration and acceptance basis. Passing that test does not, by itself, state the continuous operating envelope or suitability for a different fluid and temperature.

Does the actuator complete the selection? Choosing a pressure-containing assembly and choosing an actuator are related but separate tasks. Required torque, supply, controls and application conditions need an appropriate selection review. An actuator photograph is not evidence that every offered combination is approved for the buyer's duty.

These questions should lead to specific engineering answers. A content team should not resolve missing design information by repeating “heavy duty” or “industrial grade.”

A fictional enquiry: what can be answered and what cannot

Imagine an enquiry for a valve at 12 bar and 180°C. The buyer has found a page labelled PN16, but the page gives neither the seat option nor the applicable pressure-temperature table.

The correct editorial response is not to approve the valve because 12 is below 16. It is to identify the missing configuration and ask for the relevant manufacturer's rating and application confirmation. This fictional example provides no basis to accept or reject an actual valve.

A useful enquiry record would capture:

• The required series or function, size and end connections.
• The normal and specified design conditions, with pressure basis and temperature units.
• The fluid, relevant concentration and other service conditions supplied by the buyer.
• The proposed materials and options.
• The rating document and revision being used.
• The responsible technical approval and any conditions still open.

The order-specific review may require more information. The point is that the missing facts are visible and routed to the person who can resolve them.

Write one application boundary rather than two impressive maxima

A good product page connects its summary to a readable rating table or controlled technical document. If the data are too detailed for the page, provide a clear path to the exact document and explain which configuration it covers.

A fictional summary might read:

Pressure-temperature limits depend on the selected body, seat, seal and connection configuration. Use the rating table for the complete order code. Application conditions and material compatibility require confirmation before selection.

This is proposed copy, not a technical approval. The manufacturer should replace general language with its approved specifics where available.

Avoid a headline such as “16 bar to 200°C” unless the responsible technical owner has confirmed that the sentence describes a simultaneous operating condition for the covered configuration. A footnote lower down the page should not be expected to undo an unqualified headline.

Likewise, an English translation must preserve distinctions between working pressure, test pressure and differential pressure. Translating all three as “pressure resistance” removes information that the buyer needs.

A practical page acceptance test

Give a reviewer the page and one selected order code. Ask the reviewer to locate the following without relying on a salesperson's unstated knowledge:

1. The applicable rating document and revision.
2. The exact configuration and material column.
3. The pressure-temperature relationship and relevant notes.
4. Any separate connection, seat or seal restriction that applies.
5. The conditions the buyer must provide for the application review.
6. The contact route for unresolved technical questions.

The page passes this editorial test when the facts are traceable and the unresolved conditions remain explicit. It has not thereby passed a pressure test, a design review or a conformity assessment.

Test the same information on a phone. If the first column is visible but the material heading or a limiting footnote is cut off, the table can mislead even though the page technically contains the correct text. Keep units attached to values and repeat the table's scope where a downloadable excerpt could otherwise lose it.

Why this matters for AI answers

AI search can extract a nominal class, a maximum temperature and a product name from different passages. Publishers cannot control every summary, but they can avoid creating an easy false combination.

Place the rating condition near the claim. Use a clear configuration name. Do not add an unsupported maximum to structured descriptions or comparison tables. An accessible source table is more useful than an image containing tiny numbers with no selectable explanation.

For manufacturers preparing English buyer material, Xindar's manufacturing service can help structure approved product facts, evidence links and the enquiry path. The manufacturer's technical owner must approve the engineering claims. Marketing implementation does not certify a valve or replace the application review.

Frequently asked questions

Can I convert PN16 directly into a working-pressure limit?

Use the applicable standard and configuration-specific rating information. The PN designation alone does not establish the permitted pressure at every temperature.

Is a maximum temperature the temperature at maximum pressure?

The page must explicitly establish the simultaneous condition. Separate maxima may describe different points in the operating envelope.

Does a higher test pressure permit continuous operation at that pressure?

A test condition and a continuous operating rating answer different questions. Use the approved operating information and the applicable application review rather than inferring one from the other.

Can a marketing agency approve the rating table?

It can improve presentation, source traceability and buyer navigation. Technical approval belongs to the qualified party responsible for the product and application.

Written by Daoyu Guan. KSB's definition and the identified Swagelok catalogue section were reviewed on November 9, 2026, including the page 6 table and notes. The enquiry example is fictional. No valve was tested, selected, certified or approved for service.