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Plant Integrity & Engineering Reference

API Standards & Plant Integrity Guide

One complete engineering picture. Discover how key API standards interlock to build safe, reliable, and efficient process plants — and how NDT inspection methods and platform designers enforce compliance.

Pillar 01
Safety
Pillar 02
Reliability
Pillar 03
Availability
Pillar 04
Eco-Protection
System Map Scope
API CODES
Rotating Equipment:API 610, 617, 618, 619
Auxiliary Systems & Seals:API 614, 682, 692
Machinery Protection:API 670
Pressure & Piping Code:API 510, 570
Risk-Based Inspection:API 580, 581
Relief & Safety Systems:API 520, 521
Audience:Level II/III & Plant Engineers
Showing 11 standards
API 610Rotating Equipment
Reliability

Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas Industries

Design and performance requirements for centrifugal pumps used in critical refinery and process applications.

Core Technical Focus

Minimum mechanical reliability, casing pressure containment, dynamic balancing, and vibration performance.

Mandatory Requirements:
30-year design life & minimum 3-year continuous operation
Heavy-duty radially split casing for high pressure/temperature
Shaft deflection limits at seal face (< 0.05 mm)
Dynamic balancing of impellers to ISO 1940 Grade G2.5
Target Equipment:Centrifugal Pumps
Inspection Frequency:36 Months Continuous
API 617Rotating Equipment
Availability

Axial and Centrifugal Compressors and Expander-compressors

Defines minimum requirements for axial and centrifugal compressors used in severe gas service.

Core Technical Focus

Aero-thermodynamic efficiency, rotor stability analysis, dry gas sealing integration, and casing integrity.

Mandatory Requirements:
Rotor lateral and torsional vibration analyses
Hydrostatic pressure testing of casing to 1.5× max allowable working pressure
Impeller NDT inspection for sub-surface indications
Impeller spin testing at 115% trip speed
Target Equipment:Centrifugal & Axial Compressors
Inspection Frequency:48 Months Major Turnaround
API 618Rotating Equipment
Reliability

Reciprocating Compressors for Petroleum, Chemical, and Gas Industry Services

Standard for design, operation, and maintenance of heavy-duty reciprocating compressor systems.

Core Technical Focus

Pulsation control, cylinder thermal stress, rod load limits, and valve assembly reliability.

Mandatory Requirements:
Acoustic pulsation simulation & vibration mitigation analysis
Non-destructive examination of crankcase & forged shafts
Rod drop monitoring & thermal displacement verification
Cylinder liner ultrasonic thickness mapping
Target Equipment:Reciprocating Compressors
Inspection Frequency:12 - 24 Months Maintenance
API 619Rotating Equipment
Availability

Rotary-Type Positive-Displacement Compressors

Requirements for dry and oil-flooded rotary positive displacement (screw) compressor systems.

Core Technical Focus

Rotor profile mesh verification, thermal growth clearance, and continuous gas delivery stability.

Mandatory Requirements:
Precision clearance measurement across rotor lobes
Nondestructive evaluation of rotor shaft forgings
High-pressure casing leak testing with nitrogen/helium tracer
Bearing housing vibration spectral screening
Target Equipment:Screw Compressors
Inspection Frequency:36 Months Service Interval
API 614Auxiliary & Seals
Reliability

Lubrication, Shaft-Sealing and Control-Oil Systems

Ensures reliable lubrication, shaft-sealing, and control oil supply for critical rotating equipment.

Core Technical Focus

Dual redundant pump systems, oil reservoir filtration, thermal regulation, and emergency lube accumulator pressure.

Mandatory Requirements:
100% standby oil pump auto-transfer within milliseconds
ISO 4406 fluid cleanliness class 15/13/10 monitoring
Stainless steel piping for seal oil delivery loops
Accumulator emergency run-down capability for coast-down
Target Equipment:Lube & Seal Oil Skids
Inspection Frequency:Continuous Fluid / Annual NDT
API 682 / 692Auxiliary & Seals
Eco-Protection

Pumps & Gas Compressors Mechanical Shaft Seals

Standards for mechanical seals and dry gas seal support systems in hazardous hydrocarbon service.

Core Technical Focus

Zero-emission containment, dry gas face separation clearance, seal flush piping plans (Plan 52/53/74).

Mandatory Requirements:
API 682: Standardized seal cartridges & qualification test protocols
API 692: Dry gas seal separation gas pressure control & leakage detection
Secondary seal containment barrier for volatile organic compounds (VOCs)
Face flatness inspection to < 2 helium light bands
Target Equipment:Mechanical Seals & Dry Gas Seals
Inspection Frequency:Continuous VOC Monitoring
API 670Machinery Protection
Safety

Machinery Protection Systems

Covers continuous monitoring of shaft vibration, axial position, speed, phase reference, and bearing temperatures.

Core Technical Focus

Hardware trip logic fault-tolerance, proximity probe calibration, and automatic trip protection against catastrophic failure.

Mandatory Requirements:
2-out-of-3 (2oo3) voting logic for critical shutdown trips
Continuous radial shaft vibration (orbit analysis) monitoring
Thrust bearing displacement monitoring with dual proximity probes
Overspeed protection response time < 40 milliseconds
Target Equipment:Vibration & Trip Systems
Inspection Frequency:Continuous Online Monitoring
API 510Pressure & Piping
Safety

Pressure Vessel Inspection Code: In-service Inspection, Rating, Repair, and Alteration

Covers inspection, repair, alteration, and re-rating of pressure vessels operating in process industries.

Core Technical Focus

Remaining life assessment, minimum required thickness calculation, internal corrosion mapping, and weld integrity.

Mandatory Requirements:
Ultrasonic thickness wall mapping (UT Grid)
Phased Array UT (PAUT) & TOFD weld examination
Maximum Allowable Working Pressure (MAWP) recalculation
Stress corrosion cracking (SCC) magnetic particle/penetrant testing
Target Equipment:Pressure Vessels & Reactors
Inspection Frequency:Max 10 Years or 1/2 Remaining Life
API 570Pressure & Piping
Safety

Piping Inspection Code: In-service Inspection, Rating, Repair, and Alteration of Piping Systems

In-service inspection code for process piping circuits, elbows, injection points, and deadlegs.

Core Technical Focus

Corrosion Under Insulation (CUI), localized erosion at elbows/tees, injection point decay, and fatigue cracking.

Mandatory Requirements:
Pulsed Eddy Current (PEC) or Guided Wave UT for CUI screening
Radiographic profile testing for small-bore piping wall loss
Injection point ultrasonic baseline grid monitoring
Deadleg thickness verification and drainability auditing
Target Equipment:Process Piping Circuits
Inspection Frequency:Class 1 Piping: 5 Years max
API 580 / 581Inspection & RBI
Reliability

Risk-Based Inspection (RBI) Framework & Quantitative Methodology

Methodology to calculate risk profiles (PoF × CoF) to optimize inspection intervals and target critical damage mechanisms.

Core Technical Focus

Probability of Failure (PoF), Consequence of Failure (CoF), damage mechanism modeling (thinning, SCC, HTHA, fatigue).

Mandatory Requirements:
Quantitative risk ranking across all plant fixed assets
Inspection effectiveness credit assignment for NDT techniques (PAUT vs RT vs Spot UT)
High-Temperature Hydrogen Attack (HTHA) susceptibility mapping
Dynamic inspection interval adjustment based on real corrosion rates
Target Equipment:Entire Plant Asset Fleet
Inspection Frequency:Dynamic Risk-Based Matrix
API 520 / 521Relief & Safety
Safety

Sizing, Selection, Installation & Pressure-Relieving Systems in Refineries

Governs pressure relief valves (PRVs), rupture disks, flare headers, and emergency depressurization systems.

Core Technical Focus

Overpressure scenario relief rates, acoustic fatigue in flare piping, valve seat tightness, and flare radiation.

Mandatory Requirements:
Overpressure relief sizing for fire, runaway reaction, & power loss
PRV bench pop testing and seat leak testing to API 527
Flare header ultrasonic wall thickness monitoring for internal corrosion
Acoustic induced fatigue (AIF) risk assessment on relief branch lines
Target Equipment:Pressure Relief Valves & Flares
Inspection Frequency:PRV Bench Test: 3-5 Years
Interactive Field Tools

Platform Designers & Governing Standards

NDT Exchange includes built-in digital modeling and inspection mapping tools engineered around international codes and API standards.

View Designers Documentation
API 650 / 653

Storage Tank Designer

Maps shell course thickness, annular stress rings, and MFL floor plate grids compliant with API 650 & API 653 tank inspection codes.

/tank-designerOpen Tool
TEMA R/C/B • API 660

TEMA Tube Designer

Generates heat exchanger tubesheet geometry, pitch patterns (30°, 45°, 60°, 90°), and maps ECT/IRIS/APR tube plugging & wall loss.

/temadesignerOpen Tool
ASME Sec V • ISO 13588

PAUT Scan Plan Designer

Calculates ray tracing, sound path skip distances (0.5, 1.0, 1.5 legs), and beam coverage over weld profiles for ASME Sec V Art. 4 compliance.

/ndt-scan-planOpen Tool
ASME Sec V • ISO 18563

NDT Setup Builder

Models ultrasonic probe array parameters, focal law law sweeps, wedge velocity refraction angles (Snell's Law), and near-field beam limits.

/ndt-setup-builderOpen Tool

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