Buyer takeaway
A valid report identifies the casing, test boundary, pressure basis, medium, instruments, hold record, observations, acceptance criteria, and disposition of any repair. Do not approve a report that gives only a pressure number without the conditions that make the number meaningful.
What a hydrostatic test proves
The test applies liquid pressure to a defined pressure-containing boundary for a defined procedure and period. The result supports an acceptance decision for that boundary under the stated conditions. It is one part of a quality package, not a substitute for every other inspection.
- It may demonstrate: pressure-boundary integrity under the specified test setup and acceptance criteria.
- It does not demonstrate: pump curve, efficiency, NPSH, motor load, vibration, material compatibility, corrosion rate, fatigue life, seal performance, bearing life, or field commissioning.
- It cannot repair: an unidentified casing, incomplete venting, wrong boundary, missing calibration, or an undocumented deviation.
For a replacement casing or pump, connect the hydrostatic record to the drawing revision, casting or serial identification, material record, and inspection plan. This makes it possible to tell whether the test applies to the component being purchased.
Define the test boundary
Before the test, identify the pressure-containing parts and the openings that are included, isolated, blanked, vented, or excluded. The boundary may include a casing, cover, stuffing-box or seal chamber, nozzle, drain, or temporary connection depending on the approved procedure.
- Component ID, drawing and revision, material and casting/heat reference.
- Pressure boundary and all ports, plugs, blinds, valves, gaskets, and temporary fittings.
- Test medium, cleanliness, temperature, vent and drain arrangement.
- Test pressure basis, hold-time basis, instrument locations, and acceptance criteria.
- Personnel responsible for setup, inspection, witnessing, and report approval.
Do not assume that a casing test covers the complete pump assembly. If the purchased scope includes multiple pressure-containing parts, the test plan should state whether each part is tested separately or within an assembly and how the results are linked.
Where test pressure and hold time should come from
Do not copy a universal number from another pump. Test pressure and hold time should be defined by the current applicable standard, project specification, approved manufacturer procedure, and the component’s MAWP or design basis. The controlling document for the order must identify the scope and acceptance rule.
API 610 / ISO 13709 requirements are associated with petroleum and petrochemical process-pump projects; they should not automatically be applied to every ANSI B73.1 chemical-process pump. Likewise, a project invoking EN 12162 may have a different procedure basis. Confirm the purchased standard edition and project datasheet before approving a numeric requirement.
| Reference | Relevant context | Buyer action |
|---|---|---|
| ASME B73.1-2026 | Horizontal end-suction chemical process pump specification | Verify hydrotest requirements against the current purchased standard and project datasheet |
| API 610 / ISO 13709 | Petroleum and petrochemical process pumps | Do not automatically apply API requirements to a B73.1 project |
| EN 12162 | Hydrostatic testing procedure for liquid-pump pressure-containing parts | Use when the project or specification invokes it |
| Manufacturer/project procedure | Actual boundary, pressure, hold, medium, and acceptance | Treat the approved order procedure as the controlling execution document |
Review the current ASME B73.1 information for scope context, but obtain the purchased standard and project requirements that govern the actual order.
Instrumentation and calibration
The report should allow a reviewer to understand what the gauge showed and whether the instrument was suitable for the test. Record:
- Gauge or transducer ID, range, resolution, location, and calibration status.
- Calibration certificate reference and validity at the test date.
- Pressure-time record, including pressure rise, stabilization, hold interval, and release.
- Test-medium identity and temperature, plus any relevant ambient or component temperature.
- Witness names, inspection times, visible leakage observations, and photographs where required.
A pressure reading without the boundary, instrument identity, and time record is difficult to audit. If the project requires a recorder, preserve the native record or a traceable export with the report.
What invalidates a test
- Incomplete venting leaves trapped air or an unverified high point.
- The wrong boundary is tested, or an opening is unintentionally isolated.
- A temporary connection, plug, blind, gasket, or valve leaks.
- The gauge is out of calibration, unidentified, damaged, or poorly located.
- The casing or casting cannot be tied to the report by a unique ID.
- A weld, repair, machining change, or casting disposition is undocumented.
- No pressure-time or hold record exists where one is required.
- The medium, temperature, pressure basis, or acceptance criteria are missing.
These conditions do not necessarily mean the component is unusable; they mean the result is not sufficient evidence until the responsible engineer or quality authority determines the disposition under the approved procedure.
Repaired casting or weld: when engineering disposition is needed
Repair acceptance depends on the material, repair method, location, geometry, service, design basis, and project procedure. Do not publish a universal rule for repaired castings or assume that a successful pressure test closes every concern. A repair may require additional examination, heat treatment, dimensional review, material traceability, or engineering approval before retest and release.
For a new or repaired casing, request the repair map, approved disposition, applicable NDE or inspection records, material and heat information, dimensional status, hydrotest report, and any deviation approval required by the project. The ANSI B73.1 compatibility guide is useful when a pressure-containing replacement also needs dimensional and fitment verification.
Buyer hydrotest report checklist
- Purchase order, project, pump model and component scope.
- Casing/part ID, casting or serial reference, drawing number and revision.
- Material grade and traceability reference.
- Defined pressure boundary, ports, blanks, plugs and exclusions.
- Test medium and relevant temperature.
- Pressure basis and approved procedure revision.
- Gauge/transducer IDs, ranges, calibration references and locations.
- Pressure-time record, stabilization and hold information.
- Acceptance criteria and visible inspection result.
- Repair, deviation, witness, photograph, or NDE references where applicable.
- Inspector, witness and approval signatures or traceable electronic approvals.
- Final disposition: accepted, retest required, repaired and re-approved, or rejected.
Hydrotest versus performance test
| Test | Primary question | Typical evidence |
|---|---|---|
| Hydrostatic test | Does the defined pressure boundary withstand the specified liquid-pressure condition? | Boundary, pressure basis, medium, instruments, hold record and acceptance |
| Performance test | Does the pump produce the specified hydraulic result under the defined test condition? | Flow, head, power/efficiency, speed, fluid basis, instruments and curve comparison |
| Field commissioning | Does the installed pump operate correctly in the actual system? | Installed duty, suction, discharge, controls, vibration, temperature, leakage and process state |
A hydrostatic test does not replace performance testing or commissioning. For an RFQ that includes all three, keep their acceptance criteria and records separate. The ANSI pump RFQ and commissioning checklist shows how to define those scopes before the PO.
For additional industry context, see the Hydraulic Institute article on optimizing hydrostatic testing procedures for pump casings. It should supplement, not replace, the current project and manufacturer procedure.
Need to review a pump casing hydrotest report?
Send the component ID, drawing revision, material record, approved procedure, pressure-time record, gauge calibration references, repair/deviation documents, and acceptance criteria. ANSI Pumps Pro can help identify missing evidence before a casing or replacement-parts package is released.
FAQ
What does a pump casing hydrostatic test prove?
It provides evidence about the integrity of the defined pressure-containing boundary under the stated liquid-pressure condition and acceptance criteria.
Does a hydrostatic test prove pump performance?
No. Hydraulic performance, NPSH, efficiency, power, vibration, seal life, material suitability, and field operation require separate evidence.
How is hydrostatic test pressure selected?
Use the current applicable standard, project specification, approved manufacturer procedure, and the component’s MAWP or design basis. Do not copy a universal number from another pump.
What should be on a hydrotest report?
Include component identity, boundary, material traceability, medium, pressure basis, instruments and calibration, pressure-time or hold record, acceptance criteria, observations, deviations, and final disposition.
Can a repaired casing be accepted after a successful hydrotest?
Not automatically. Repair acceptance depends on the material, repair method, location, service, project procedure, additional inspection, and engineering disposition required for that component.
