Learn how to size, select, and position PSVs using industry-approved methods—hands-on, scenario-based, and standard-compliant.

Course Description

This intensive workshop takes engineers through the complete PSV sizing workflow, from defining overpressure scenarios to selecting appropriate valves and orifice sizes. Based on API 520/521 standards, the course emphasizes practical scenario manipulation, orifice sizing, code compliance, and field realities.
Participants will go beyond theory to apply sizing logic to real cases including fire scenarios, thermal expansion, control valve failure, blocked flow, gas blow-by, and heat exchanger tube rupture. Through structured examples, attendees will calculate set pressures, evaluate orifice designations, and choose flange sizes. The workshop also clarifies the roles of process and I&C disciplines in relief device sizing.
Ideal for engineers responsible for mechanical design, process safety, flare systems, and regulatory compliance, this course combines clear explanations with engineering depth.

Who Should Attend

Process Engineers | Mechanical Engineers | I&C Engineers | Safety Engineers | EPC Designers | Reliability Engineers | Regulatory Compliance Officers | Plant Operators | Project Engineers

Training Methodology

✔ API 520/521-based methods

✔ Hands-on examples: multiple PSV sizing cases

✔ Flowcharts and logic diagrams to simplify selection

✔ Flange & orifice tables decoded

✔ Real-world layout guidance: piping drops, back pressure, bypasses

✔ Instructor-led interactive problem solving

Organizational Benefits

Avoid under- or over-sizing PSVs across the facility
Comply with international codes and best practices
Understand cross-discipline boundaries (Process vs. I&C)
Size PRVs accurately across fire, thermal, and gas blow-by cases
Ensure long-term reliability and safe plant operation

What You Will Learn

✔ Six steps to building a protective layer

✔ PRD location, positioning, set pressure, and orifice sizing

✔ Differences between design pressure, MAWP, and set pressure

✔ Inlet/outlet pressure drop limits (3% rule)

✔ PSV selection by fluid type, set point accuracy, and service conditions

✔ Common overpressure scenarios and how to manipulate/discredit them

✔ API orifice sizing methodology for gas, steam, and liquid

✔ Pilot-operated vs. conventional vs. bellows valves

✔ Series vs. parallel PRD arrangements (spares, rupture discs, headers)

✔ Relief valve datasheet interpretation and vendor communication

Seminar Outline (Highlights)

Fundamentals and Scenario Building • Six key steps in protective system design • Identifying and evaluating overpressure scenarios • Control valve failure, gas blow-by, blocked flow • Shell & tube exchanger tube rupture • Fire and thermal expansion scenarios • Valid vs. non-credible cases • Scenario discrediting & derating tools • Positioning PRDs: piping limits, vibration, access • Selecting PRD types and arrangements (spare, parallel, rupture disc)
Orifice Sizing & Practical Application • Set pressure logic: MAWP, design pressure, operating pressure • Understanding overpressure and blowdown • API 520 sizing methods: subcritical and critical flow • Orifice letter designation (D through T) • Flange size and rating selection using API 526 • Back pressure limits for spring and pilot-operated valves • Case studies: fire pool, exchanger rupture, valve failure • Datasheet development & field installation checks • Process vs. I&C responsibility for final valve selection

Practical Takeaways

✔ PSV sizing templates and datasheets

✔ Scenario definition & checklist worksheet

✔ Flange & orifice quick reference tables

✔ Orifice sizing examples for gas, steam, and liquid

✔ Field layout guide: access, vibration, spacing

✔ Certificate of completion

Course FAQ

Q: Does the course cover fire and thermal cases?

 A: Yes. Detailed guidance is given on API 521 fire scenario calculation and thermal expansion from trapped liquid.
 

Q: Do I need to use software? 

A: No software is required. All sizing is done manually using API-based formulas and orifice tables.

Q: Is the workshop hands-on? 

A: Absolutely. You’ll complete several PSV sizing problems in class with instructor guidance.

Q: Will I learn how to handle rupture discs and pilot valves?

 A: Yes. The course covers both selection and arrangement options (e.g., rupture disc upstream of PRV).

Q: Is this course for process or I&C engineers?

 A: Both. The course bridges the gap between process calculation and instrumentation implementation.

What Past Participants Say

— “Helped me correctly size for fire pool cases without overdesign.” – Process Engineer
— “Finally understood the 3% rules and orifice designations.” – Mechanical Engineer
— “Great workshop with clear logic and solid examples.” – Safety Engineer
— “Brilliant explanation of parallel and series PRD arrangements.” – I&C Lead