ASME
ASME B31.3
Process Piping
The design and construction code for process piping in refineries, chemical plants and pharmaceutical facilities. It sets out how pipe wall thickness is calculated, which materials may be used at which temperatures, what welding and examination each fluid service requires, and how systems are pressure tested. Fluid service category — normal, category D, category M, high pressure — is the decision that drives most of the rest.
This is an explanation, not the standard. PipingInspector is not affiliated with ASME and reproduces no part of the document. Always work to the current edition of the standard itself and to your project specification.
Where it is applied on this site
- Reading a P&ID — the drawing every discipline works fromInstrumentation & Control
- Instrument installation and loop checking — where most readings go wrongInstrumentation & Control
- Pipe materials — what the grade on the spec actually meansPiping
- Pipe sizes and schedules — why NPS 2 is not 2 inchesPiping
- Line sizing — why pipe diameter is an economic decisionPiping
- Fittings and branch connections — how a pipe changes directionPiping
- Flanges and pressure classes — why Class 150 is not 150 psiPiping
- Reading a line class — the document that has already decidedPiping
- Pipe supports and thermal expansion — why you cannot just bolt it downPiping
- Expansion loops and offsets — sizing the detour that absorbs the growthPiping
- Expansion joints and bellows — pressure thrust and why they are the last resortPiping
- Anchors, guides and restraint schemes — deciding where the pipe may movePiping
- Pipe support standards and details — reading SP-58, SP-69 and a project detail sheetPiping
- Spring hanger selection — variable, constant, and the pin nobody pulledPiping
- Nozzle loads and allowables — the constraint that really governs hot pipingPiping
- Pump piping layout — the suction side is where the decisions are madePiping
- Plot plan and equipment spacing — the drawing everything else inheritsPiping
- Access, operability and maintenance space — what the plant is judged on afterwardsPiping
- Relief valve and flare piping — the 3 per cent rule, backpressure and reaction forcePiping
- Welding processes, WPS and NDT — what happens before an arc is struckPiping
- Reading a WPS and a PQR — what is on the sheet and what the tests provedPiping
- Section IX essential variables — what invalidates a procedure qualificationPiping
- Welder qualification and continuity — the ranges a ticket covers, and the register nobody updatesPiping
- Joint preparation and fit-up — the hold point you only get oncePiping
- Preheat and post-weld heat treatment — hydrogen, hardness, and reading the chartPiping
- Non-destructive examination — choosing the method and reading the resultPiping
- Examination extent and progressive sampling — what five per cent actually obligesPiping
- Inspection and test plans — hold, witness, review, and who signsPiping
- Non-conformance and corrective action — the four dispositions, and why NCRs repeatPiping
- From isometric to installed line — fabrication, erection and testingPiping
- Pressure test packs and reinstatement — the gate, and what gets put back afterwardsPiping
- Tie-ins and shutdown windows — preparing for the hours that cannot be extendedPiping
- Supervising under a permit — the shift you signed forPiping
- What the plant actually does — the shape of a processProcess
- Reading a PFD and the material balance — where every number startsProcess