Pressure Rating Basics: Working, Burst and Safety Factor

A hose data sheet's working pressure is the service rating for the identified product, size and stated conditions. Read the row for the actual hose, rather than taking the largest number printed anywhere on a catalogue page. Record the units and all relevant qualifications.

The complete assembly can be limited by the hose, connectors or their permitted combination. SAE J517 states that an assembly's maximum working pressure must not exceed the lower applicable working-pressure value of its hose and connectors. A high-rated hose does not raise the rating of a lower-rated connection.

Minimum burst pressure refers to a destructive-test requirement under specified conditions. A test specimen is taken to a pressure used to evaluate that requirement. It does not represent an acceptable operating point for an installed assembly.

Do not decide that a pressure surge is acceptable merely because it sits below the burst figure. The system must remain within the permitted working limits of the selected assembly. Repeated loading, temperature and other service conditions also matter; a burst result cannot be converted into a prediction of remaining life.

Where a specification defines it this way, the pressure design factor is the ratio of minimum burst pressure to rated working pressure. Read the actual product and standard requirements rather than assuming the same ratio applies to every hose or application.

That relationship explains a test margin. It does not authorise the operator to spend the margin by increasing machine pressure. Nor should it be used to calculate a new working rating for an unidentified hose with only a burst figure available.

When comparing offers, ask whether the stated factor comes from the relevant product specification and applies to the proposed size. Avoid replacing missing working-pressure data with arithmetic based on a marketing statement.

A proof test applies a specified non-destructive test condition to check an assembly under the applicable procedure. Its pressure and duration must come from the agreed requirement. Do not improvise a test pressure by copying another hose family or multiplying the system setting.

Impulse testing evaluates repeated pressure loading under defined laboratory conditions. A successful proof test is not evidence of a particular impulse life, and an impulse qualification does not guarantee a fixed service life on a machine. Keep test records and application selection as separate parts of the engineering review.

1. Confirm product identity, size and document revision.
2. Locate the working-pressure value and its units.
3. Read temperature, fluid and application limitations alongside that value.
4. Identify the permitted connection and assembly system.
5. Check bend radius and installation requirements.
6. Record the required inspection and testing scope separately.

For fleet procurement, attach this information to the circuit requirement. If a quoted replacement changes the hose or fitting family, request confirmation of the resulting assembly limits. A supplier's familiar part description is not a substitute for that review.

Have qualified personnel establish the relevant circuit pressure, including transients, using appropriate equipment and procedures. A slow gauge or nominal machine setting may not describe every pressure event. Never increase a relief setting to compensate for an unexplained performance problem.

Give the supplier the operating information and any abnormal pressure history, then retain the accepted selection with the maintenance record. If pressure, fluid or temperature changes, review the assembly again. The useful question is whether its documented service limits suit the circuit, not how close operation can approach a destructive-test number.