API 570 Piping Inspector Exam: Free Practice Questions (2026)

The API 570 Piping Inspector Certification is one of the most valuable credentials in the oil and gas inspection industry. Issued by the American Petroleum Institute, it validates your ability to inspect, repair, and rerate in-service metallic piping systems — and it's a prerequisite for most senior piping inspector roles on major energy projects worldwide.

This guide covers everything you need to know to pass the API 570 exam on your first attempt: eligibility, exam format, the key topics that appear most frequently, and a proven study strategy.

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What Is the API 570 Certification?

API 570 is the API's standard for Inspection, Repair, Alteration, and Rerating of In-Service Piping Systems. The certification program tests your knowledge of this document along with several referenced codes. It's designed for inspectors who are responsible for maintaining the mechanical integrity of piping systems after they've been placed in service.

The certification is valid for 3 years, after which you must recertify — either by earning continuing education points or by retaking the exam.

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Eligibility Requirements

Before you can sit for the API 570 exam, you must meet API's education and experience requirements:

Education Level	Required Experience
High school diploma	5 years of relevant industrial experience
2-year technical degree	3 years of relevant experience
4-year engineering degree	1 year of relevant experience

"Relevant experience" means work involving inspection, engineering, construction, or maintenance of piping systems. You'll need to document this experience on your application with employer verification.

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Exam Format

• Number of questions: 100 multiple-choice (some pre-test, unscored)
• Time limit: 3.5 hours (210 minutes)
• Format: Open-book — approved code documents allowed
• Passing score: Determined by a cut score (typically ~70%)
• Delivery: Computer-based testing at API-approved exam centers

The open-book format is a double-edged sword. You have the codes in front of you, but the exam is designed so that candidates who don't know the material well will run out of time looking things up. You need to know where information lives in each document and be able to navigate to it quickly.

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Key Topics and Weight Distribution

The API 570 exam draws from multiple documents. Understanding the weight distribution helps you allocate study time efficiently:

1. API 570 — Piping Inspection Code (~30%)

This is the core document. You must know:

• Inspection intervals and risk-based inspection (RBI) concepts
• Corrosion monitoring and CMLs (Condition Monitoring Locations)
• Thickness measurement programs
• Repair methods (temporary and permanent)
• Rerating and alteration procedures
• Records and documentation requirements

2. API 574 — Inspection Practices for Piping (~15%)

Covers practical inspection techniques:

• Visual inspection of external piping
• CML selection and thickness measurement
• CUI (Corrosion Under Insulation) inspection
• Small-bore and deadleg inspection
• Injection point inspection

3. ASME B31.3 — Process Piping (~20%)

Focus areas:

• Table 341.3.2 acceptance criteria for welds
• Pressure testing requirements (hydrotest, pneumatic)
• Heat treatment requirements
• Welding requirements (WPS/PQR/WPQ)
• Pre-heat and post-weld heat treatment (PWHT)

4. API 510 — Pressure Vessel Inspection (~10%)

Shared content on:

• Inspection intervals
• Corrosion rate determination
• Remaining life calculations
• NDE methods overview

5. NACE SP0174 — Cathodic Protection (~5%)

• External corrosion control for buried piping
• CP system basics and monitoring

6. ASME B16.5 — Flanges (~5%)

• Flange ratings and pressure-temperature ratings
• Gasket and bolting requirements

7. General Inspection Knowledge (~15%)

• NDE methods (RT, UT, MT, PT, VT)
• Welding fundamentals
• Materials and corrosion basics
• Documentation and record-keeping

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Study Strategy: A 12-Week Plan

Weeks 1–4: Build the Foundation

Read API 570 cover to cover. Don't try to memorize — understand the structure. Tab the document with sticky notes so you can flip to key sections quickly during the exam. Focus on inspection intervals, repair categories, and rerating procedures.

In parallel, read API 574. This document is shorter and more practical — it describes how to inspect piping in the field. Understanding the connection between API 570 (the requirements) and API 574 (the execution) makes both documents easier to retain.

Weeks 5–8: Deepen with ASME B31.3

ASME B31.3 is the second most heavily weighted document. Spend these weeks studying:

• Chapter V — Examination and Inspection (especially Table 341.3.2)
• Chapter VI — Pressure Testing (hydrotest procedures, test pressures)
• Chapter VII — Welding (WPS, PQR, essential variables)

Practice looking up acceptance criteria in Table 341.3.2 — this is one of the most frequently tested areas. You should be able to find the applicable row for a given weld condition in under 30 seconds.

Weeks 9–10: Practice Questions

This is where most candidates make or break their preparation. Reading the codes is necessary but not sufficient — you need to practice applying them to exam-style questions. Use the SkillJet.co QC simulator to drill piping-specific questions with realistic scenarios. Focus on:

• Calculating remaining life and corrosion rates
• Determining inspection intervals
• Identifying acceptable vs. unacceptable weld defects per Table 341.3.2
• Selecting appropriate repair methods

Weeks 11–12: Full Mock Exams

Take full-length mock exams under timed conditions. The SkillJet.co final certification exam mirrors the real exam format: 50 questions, 60 minutes, no instant feedback, auto-submit. Aim for 80%+ consistently before sitting for the real exam.

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Common Pitfalls That Cause Failed Attempts

1. Over-relying on the open-book format

Many candidates assume they can look up every answer. With 100 questions in 210 minutes, you have just over 2 minutes per question. If you need to look up more than 30% of answers, you will not finish. Know the material well enough to answer 70% from memory.

2. Not tabbing your code books

During the exam, every second counts. Tab your API 570, API 574, and ASME B31.3 with clearly labeled sticky tabs for major sections. Practice navigating to specific tables and paragraphs during your mock exams.

3. Ignoring the math questions

The exam includes calculations for remaining life, corrosion rates, and inspection intervals. These are straightforward but require practice. Don't skip them — they're easy points if you've practiced the formulas.

4. Not understanding CUI

Corrosion Under Insulation is heavily tested because it's one of the most common failure mechanisms in piping. Make sure you understand CUI inspection strategies, susceptible temperature ranges, and mitigation methods.

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What to Bring on Exam Day

• Your government-issued photo ID
• Your API exam authorization letter
• Tabbed copies of all approved code documents (API 570, API 574, ASME B31.3, API 510, ASME B16.5, NACE SP0174)
• A basic non-programmable calculator (if allowed by your testing center)

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Start Your Preparation Today

The API 570 exam is challenging but absolutely passable with the right preparation. The key is consistent study over 3–6 months, combined with realistic practice under exam conditions.

Start with a free diagnostic on SkillJet.co to identify your weak areas across piping inspection, welding codes, and NDE methods. Then drill those areas specifically before attempting the final certification mock exam. When you can consistently score 80%+ on the simulator, you're ready for the real thing.