API 521 : Pressure Relieving and De-Pressuring Systems

An Intensive 5-Day Online Training Course

API 521 : Pressure Relieving and De-Pressuring Systems

We currently have no scheduled session for this Course. If you are interested in running this course, please contact our Training Department at info@petroknowledge.com

Why Choose this Training Course?

Why Choose this Online Training Course?

In order to have an effective depressurization & vapor relief system; you need to know how you can select, size & operate it. This PetroKnowledge online training course is applicable to pressure-relieving and vapor de-pressuring systems. The online training course is applicable to petrochemical facilities, gas plants, liquefied natural gas (LNG) facilities, and oil and gas production facilities. Pressure vessels and other equipment require relief devices to provide overpressure protection to prevent conditions that may cause serious injuries to personnel, costly mechanical damage, and environmental releases. The online training course gives you specific detailed guidelines for evaluating a relief system, including determining the applicability of overpressure scenarios, required relief rates, and relief device capacity. Flare system calculations such as flare thermal radiation zone & purge gas rates is also included.

This PetroKnowledge online training course will highlight:

  • Fundamentals of Pressure Relief Valve Design & Operation
  • Overpressure Scenarios
  • Selecting and designing disposal systems, including such component parts as piping, vessels
  • Selection & design of the flares, and vent stacks

What are the Goals?

What are the Goals?

For many decades of the last century. Process vents and pressure relief flows were directed, individually or collectively, to the atmosphere unburned. Gases separated from produced oil were also vented to the atmosphere unburned. The custom of unburned venting began to change later when increased environmental awareness and safety concerns created the desire to convert vents to continuously burning flares.

By the end of this PetroKnowledge online training course, participants will learn to:

  • Understand the importance of pressure relief systems and their key principles
  • Select and size appropriate relief devices (e.g. Pressure safety valves)
  • Calculate flare header thermal radiation zones & purge rates
  • Understand the flare system equipment operations & maintenance
  • Understand the zero flare principles

Who is this Training Course for?

Who is this Online Training Course for? 

This PetroKnowledge online training course addresses the needs of a diverse audience with an interest in pressure relieving & flare systems. This online training course is suitable to a wide range of professionals but will greatly benefit:

  • Process Engineers involved in relief & flare selection and sizing
  • Operation Engineers who have oversight responsibility for flare design & operation
  • Technical personnel & supervisors involved in supporting relief flare operation

How will this Training Course be Presented?

How will this Online Training Course be Presented?

This PetroKnowledge online training course will utilize a variety of proven online learning techniques to ensure maximum understanding, comprehension, retention of the information presented. The training course is conducted Online via an Advanced Virtual Learning Platform in the comfort of any location of your choice.

Organisational Impact

All companies are trying to set up a safe, reliable & compliant operations; hence their employees such as process & operation engineers shall have a full understanding of vapor relief & flare systems:

  • Improve organization integrity
  • Enhance organization KPI
  • Reduce operation losses
  • Achieve the class excellence in operations management

Personal Impact

Poor handing of Pressure-relieving and De-pressuring Systems has the potential to asset damage & personnel incidents which will be the worst scenario ever. This PetroKnowledge online training course will have impact on the personal as follows:

  • Understand the hierarchy of protective measures
  • Aware of the pressure relief causes & actions required
  • Best practices in relief system & flare operations
  • Special consideration when selecting & sizing these systems
  • Health & safety aspects associated with operation & maintenance of the relieving systems

Daily Agenda

Day One: Introduction to Pressure Relief Valve Design & Operation

  • Codes & standard
  • Overpressure Scenarios
  • Causes of over pressure and their relieving rates
  • What is pressure safety valve?
  • Major components of the pressure safety valve
  • Types of pressure safety valve
  • Conventional pressure safety valve
  • Balanced bellows pressure safety valve

Day Two: Relief System Protection Philosophy

  • Role of instruments in relief & flare systems
  • Overpressure prevention during maintenance
  • Pilot Operated Pressure Safety valve
  • PSV selection criteria
  • PSV operation problems
  • Rupture disks types & operations
  • Vent stacks considerations

Day Three: Flare Systems Sizing & Operations

  • Function of the flare system
  • Flare system configuration & description
  • Cold flare Operations
  • Exercise - Flare System P&ID read & plan
  • Flare system design & selection criteria (Flow, composition, temperature … etc)
  • Safety & Environmental regulations for the flare operations
  • Flare types classification (Elevated – Ground)
  • Steam & Air Assisted Flares
  • Sonic flare definition
  • Single & Multi Point Flares
  • Burn Pits Operation, Selection & Environmental regulations

Day Four: Relief System Process Engineering Calculations

  • Line sizing
  • PSV Sizing & Calculations
  • Thermal radiation & safe zone calculation
  • Flare Purge Gas Calculations
  • Knock Out drum diameter sizing

Day Five: Relief & Flare Safety Considerations

  • Vapor relief & flare system safe operations
  • Guidance on vacuum effect
  • Flare & HSE regulations
  • Venting to atmosphere considerations
  • Air Pollution
  • Relief & flare systems commissioning & start up hazardous


  • On successful completion of this online training course, a PetroKnowledge E-Certificate will be awarded to the delegates

Frequently Asked Questions

How can I register for a training course?

  • To register online through our website, please click “Enroll Now” on the course page, complete and submit the form. A confirmation e-mail and instructions will be sent to the participant’s e-mail.
  • You may also get in touch with our Registration Team on
    +971 50 981 7386 | +971 2 557 7389 or send an email to reg@petroknowledge.com

When and how do I arrange payments?

  • Payments can be made in USD or UAE local currency AED (Arab Emirates Dirhams) either by Bank Transfer or by Credit Card. Our Bank Account details will be provided on the invoice.
  • Course fees are payable upon booking unless a valid, authorized Purchase Order is provided and accepted.
  • Invoices will be sent via email/courier to the ID/name and address provided.
  • The course fee shall be settled prior to course start date. Corporate payments with existing payment policy shall be relayed to us in advance.

When should I expect to receive confirmation of registration?

Upon successful registration online, enrolment on the respective training course will be confirmed by Registration Team by e-mail along with the invoice and joining instruction.

Is there a discount for more than one registrant/course?

For corporate fees and group registration, please send your query to info@petroknowledge.com.

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All rights reserved. Any unauthorized copying, distribution, use, dissemination, downloading, storing (in any medium), transmission, reproduction or reliance in whole or any part of this course outline is prohibited and will constitute an infringement of copyright.

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