A Quick Guide to Pressure Relief Valves (PRVs)

Where to Start - A Ten-minute Guide to PRVs.

Some Useful Websites and References.

Chapter 1. Protective Devices - An Introduction.

1.1 Terminology.

1.2 Overpressure - causes and effects.

1.3 Pressure relief.

1.4 External accreditations.

1.5 Technical standards.

1.6 Operation and maintenance.

Chapter 2. Design Fundamentals.

2.1 The "relieving system".

2.2 Fluid categorization.

2.3 Pressure classes.

2.4 PRV sizing.

2.5 The high-lift principle.

2.6 Nozzle design.

2.7 Balanced high-lift PRVs.

2.8 Seat types.

2.9 Pilot-operated PRVs.

2.10 Pressure-vacuum valves.

2.11 Thermal relief valves.

2.12 Rupture discs.

2.13 Materials of construction.

Chapter 3. Design Codes.

3.1 ANSI B16.34.

3.2 BS 6759: 1984 - safety valves.

3.3 API RP 576: 2000 Inspection of pressure-relieving devices.

3.4 Other API standards.

3.5 The PED and EN 1268.

3.6 PRV isolation.

Chapter 4. ASME VIII Requirements for PRVs.

4.1 Clauses UG-125 to UG-136.

Chapter 5. Damage Mechanism.

5.1 Chloride attack.

5.2 Stress corrosion cracking (SCC).

5.3 Sour service corrosion.

5.4 High-temperature damage mechanisms.

5.5. Fatigue.

5.6 Fire damage.

5.7 Mechanical damage.

5.8 Damaged seating surfaces.

Chapter 6. PRV Inspection Periodicity and RBI.

6.1 Inspection periodicity and life cycle.

6.2 RBI schemes.

Chapter 7. PRV Inspection and Testing.

7.1 Shop tests.

7.2 In-service PRV testing.

7.3 Stripdown examinations.

7.4 Workshop reassembly and testing.

7.5 Setting of PRV lift pressure.

7.6 Storage and handling of PRVs before reinstallation.

7.7 On-line lift testing.

Final Cut - That RBI thing. . .

Appendix 1. PRV Terminology.

Appendix 2. Technical Data.

Index.