Pressure vessels present significant hazards in industrial environments due to the high pressures and potentially hazardous contents they contain. OSHA 29 CFR 1910.169 establishes requirements for air receivers, while the ASME Boiler and Pressure Vessel Code (BPVC) Section VIII provides comprehensive design, fabrication, and inspection standards for vessels operating above 15 psig. API 510 (Pressure Vessel Inspection Code) governs in-service inspection, repair, alteration, and rerating for vessels in the refining and petrochemical industries, with broader applicability at owner discretion. State jurisdictions often impose additional inspection requirements and inspector licensing. This guide covers all inspection requirements with a free downloadable checklist.
Free Pressure Vessel Inspection Checklist
Download our Word document checklist covering external visual inspection, internal inspection, safety devices, and documentation per ASME/API 510.
Download Checklist (.docx)Regulatory Framework
OSHA — 29 CFR 1910.169 (Air Receivers)
- 1910.169(a): All new air receivers must be constructed per ASME BPVC Section VIII (1968 edition referenced). Every air receiver must be equipped with an indicating pressure gauge and one or more spring-loaded safety valves.
- 1910.169(b)(1): Air receivers installed so all drains, handholes, and manholes are easily accessible. Under no circumstances shall an air receiver be buried underground or located in an inaccessible place.
- 1910.169(b)(2): A drain pipe and valve installed at the lowest point of every air receiver for removal of accumulated oil and water.
- 1910.169(b)(3): Safety valves constructed, installed, and maintained per ASME BPVC Section VIII. No valve of any type shall be placed between the air receiver and its safety valve(s).
ASME BPVC & API 510
- ASME BPVC Section VIII: Provides requirements for design, fabrication, inspection, testing, and certification of pressure vessels operating at internal or external pressures exceeding 15 psig. Division 1 covers up to 3,000 psi, Division 2 up to 10,000 psi, Division 3 above 10,000 psi.
- API 510: Covers in-service inspection, repair, alteration, and rerating. External inspections at intervals not exceeding 5 years. Internal inspections not exceeding half the remaining life or 10 years, whichever is less. Risk-based inspection (RBI) per API 580 may adjust intervals.
- API RP 572: Provides inspection practices and techniques for pressure vessels, supplementing API 510 with guidance on how to conduct inspections.
- National Board Inspection Code (NB-23): Covers in-service inspection, repair, and alteration of boilers and pressure vessels for jurisdictions adopting the National Board code.
Catastrophic failure risk: Pressure vessel failures can result in explosions, shrapnel, toxic releases, and fatalities. Vessels operating beyond their maximum allowable working pressure (MAWP), with degraded wall thickness below minimum required, or with non-functioning safety relief devices pose immediate danger. Remove any vessel from service if conditions indicate potential for catastrophic failure.
Part 1: External Visual Inspection
| Inspection Item | What to Check |
|---|---|
| Shell and heads | External surface free from corrosion, pitting, erosion, blistering, bulging, or cracks. No distortion or deformation of shell or heads. Insulation intact where present (remove insulation at representative areas per inspection plan). Painting or coating condition adequate for corrosion protection. |
| Nozzles and connections | All nozzle connections tight and free from leaks. Flanged connections properly bolted with no visible seepage. Welded connections free from cracks or corrosion. Blanked or capped connections secure. No unauthorized modifications or attachments. |
| Supports and foundations | Vessel supports (saddles, legs, skirts, lugs) intact and structurally sound. Foundation free from cracking, settling, or deterioration. Anchor bolts tight and not corroded. No evidence of vessel movement or shifting. Support structure fire-proofing (if required) intact. |
| Nameplate and markings | ASME nameplate present and legible with U stamp (or applicable code stamp). Nameplate data includes MAWP, minimum design metal temperature, manufacturer, and serial number. National Board registration number visible. No unauthorized re-stamping or alterations to nameplate data. |
| Piping and connections | Connected piping adequately supported with no excessive stress on vessel nozzles. Expansion joints and flexible connections in good condition. Valves accessible and operable. Insulation not trapping moisture against vessel shell. No vibration-induced fatigue at piping connections. |
Part 2: Safety Devices & Instrumentation
| Inspection Item | What to Check |
|---|---|
| Pressure relief valves | Relief valves present and properly sized for vessel MAWP. Set pressure verified within tolerance (test per API 576 schedule). Discharge piping clear and directed safely. No block valves between vessel and relief valve per 1910.169(b)(3) (unless jurisdictionally authorized with full-area stop valve). Seals intact on adjustment mechanism. Relief valve within test/replacement interval. |
| Pressure gauges | Indicating pressure gauge present and readable per 1910.169(a)(2)(i). Gauge dial range appropriate (MAWP in middle third of range is best practice). Gauge connection not plugged or blocked. Reading consistent with known operating pressure. Gauge calibration current (annual calibration recommended). |
| Temperature instruments | Temperature gauges or sensors functioning where required. Thermowells intact and not corroded or plugged. Readings consistent with normal operating conditions. High-temperature alarms and shutdowns functional where installed. |
| Drain valves | Drain valve at lowest point of vessel per 1910.169(b)(2). Valve operable and not corroded or seized. Drain line clear and directed to safe collection. Automatic drain traps (if installed) functioning properly. Regular draining schedule maintained to remove accumulated condensate, oil, and water. |
| Level indicators | Level indicators (sight glasses, level gauges) present where required and functioning. Glass not discolored, cracked, or obstructed. Isolation valves operable. High and low level alarms functional where installed. Level readings consistent with operational expectations. |
Part 3: Internal Inspection & Documentation
| Inspection Item | What to Check |
|---|---|
| Internal surface condition | Internal surfaces free from corrosion, pitting, erosion, cracking, or deposits. Wall thickness measurements taken at condition monitoring locations (CMLs) using ultrasonic testing (UT). Remaining wall thickness above minimum required. Corrosion rate calculated and remaining life estimated. Weld seams inspected for cracking or deterioration. |
| Internal components | Internals (trays, baffles, distributors, demister pads) secure and in good condition. No loose parts that could obstruct flow or damage the vessel. Linings or coatings (if present) intact with no delamination, cracking, or holidays. Cathodic protection anodes (if installed) not depleted beyond replacement threshold. |
| Manways and access | Manway covers and gaskets in good condition. Gasket seating surfaces not damaged or corroded. Bolting adequate with no stretched or corroded fasteners. Hinge mechanisms (if present) functional. Confined space entry procedures followed per OSHA 1910.146 for all internal inspections. |
| Thickness records | Ultrasonic thickness measurements documented at all CMLs. Measurements compared to previous readings for corrosion rate trending. Minimum required thickness calculated per ASME formulas. Next inspection interval established based on remaining life. Records maintained for the life of the vessel. |
| Inspection documentation | ASME data report (U-1 form) on file. All previous inspection reports available and organized. Repair and alteration records documented per API 510 and National Board requirements. Pressure relief device test records current. Fitness-for-service evaluations documented where applicable. Jurisdictional registration and certificates current. |
Inspection interval summary (API 510, time-based): External visual inspection — not to exceed 5 years or the internal/on-stream inspection interval, whichever is less. Internal inspection — not to exceed half the estimated remaining life or 10 years, whichever is less. On-stream inspection may substitute for internal inspection when certain conditions are met. Pressure relief devices — inspected and tested per API 576 at intervals not exceeding 5 years (10 years in clean, non-corrosive service). State and local jurisdictions may impose more frequent inspection requirements.
Download the Free Checklist
Get our pressure vessel inspection checklist in Word format. Covers external, internal, safety device, and documentation inspections per ASME and API 510.
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Inspections
External and internal pressure vessel checklists with CML tracking and thickness measurement logging.
Preventive Maintenance
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Compliance Calendar
Track jurisdictional inspection due dates, registration renewals, and API 510 interval deadlines.
Task Management
Assign corrective actions for inspection findings, repair recommendations, and NDE follow-up.
Process Safety
Integrate pressure vessel integrity into PSM mechanical integrity programs and MOC workflows.
Training
Track inspector certifications, API 510 credentials, NDE qualifications, and confined space entry training.
