This publication provides introductory technical guidance for mechanical engineers and other professional engineers, construction managers and boiler plant operators interested in learning about inspection of boilers and unfired pressure vessels. Here is what is discussed: 1. INSPECTION AND TEST FREQUENCIES, 2. UNFIRED PRESSURE VESSELS, 3. BOILER INSPECTIONS, 4. UNFIRED PRESSURE VESSEL INSPECTIONS, 5. PRESSURE TESTS, 6. OPERATIONAL TESTS , 7. REPAIRS AND ALTERATIONS , 8. INSPECTION CERTIFICATES AND REPORTS, 9. MAXIMUM ALLOWABLE WORKING PRESSURE.