ASME B31.9 covers building services piping within its scope. Confirm the governing code and edition for the actual system, then compare design conditions, material specifications, connection details, supports and documented testing requirements.
Establish the piping code boundary
Identify the service, equipment connections, property boundary and governing references. A building can contain piping systems subject to different code scopes. Ask the responsible engineer to confirm applicability rather than choosing a code from the building type alone.
ASME’s current B31.9 page lists the 2025 edition. Record the edition required by the project and any referenced requirements before comparing the documents.
Keep the operating basis with the selection
Read fluid, temperature and pressure criteria with the pipe and component designations. A material name without the associated service conditions may not provide enough evidence for the designer to assess the selection.
Compare the general notes, system schedules and specification. Where units or conditions differ, preserve them in the finding so the engineer can interpret the relationship.
A hypothetical joint-detail discrepancy
Suppose a system specification identifies one joining method while a repeated detail identifies another at the same reviewed location. Record the system, pipe size, service and both references. Ask the designer to confirm whether the detail is applicable or superseded.
Backcheck related material notes, component requirements and test instructions after the decision. Do not change the connection method from a generic typical detail without the required engineering review.
Piping consistency worksheet
| Check | Sources | Review question |
|---|---|---|
| System scope | Design basis, service description and code reference | Is the selected piping code appropriate for this documented system? |
| Edition | General notes and issued specification | Do the sources name the same governing edition? |
| Service conditions | Design criteria, equipment data and schedule | Are stated fluid, temperature and pressure conditions compatible? |
| Material | Pipe schedule, specification and detail notes | Do the documented material and component designations agree? |
| Joints | Connection details, notes and specification | Are the stated joining methods consistent for the reviewed locations? |
| Support and movement | Support details, structure and design basis | Are the receiving support and stated movement assumptions documented? |
| Examination and tests | Issued test requirements and system boundaries | Can the reviewer identify the specified process and its scope? |
| Revision backcheck | Engineer decision and revised package | Did the correction reach plans, schedules, notes and details? |
Primary source and coordinated review
ASME’s B31.9 Building Services Piping page defines the standard’s scope and lists published editions. Source checked October 13, 2026.
Include your licensed applicable standard, mechanical drawings and project specification in the document comparison. The engineer verifies sizing, analysis, material suitability and the actual code requirements.
The hydronic plant case provides published mechanical coordination findings. It is not evidence that a B31.9 compliance determination was completed.