Did you know that liquid trim valves can be certified for vapor? 

There is often confusion around the required trim and certification when selecting a new safety-relief valve. For example, when there are both vapor relief scenarios and liquid relief scenarios, is a dual-certified PRV required? What about when the service is liquid but the controlling scenario is vapor? In the past, we have recommended “dual-certified” PRVs when there are both liquid and vapor relief scenarios, but these valves can be difficult to obtain or could have long lead times.  When might there be alternatives? In this discussion we will look at what liquid trim means and when different trims may be suitable for different relief possibilities.

About the Author
Mr. Smith has over a decade of experience, with a specialization in relief systems design and documentation, PSM compliance audit reviews, heat and material balance generation, PHA concern resolution, and flare system integration and optimization. Dustin is a chemical engineering graduate of Texas A&M University, a licensed Professional Engineer in Texas and LOPA certified.

The COVID-19 Challenge

As the COVID-19 disease became a pandemic in the span of mere weeks in USA (months for the world), most of us who work in the process safety/engineering field has probably asked, or been asked:

• What kind of precautions have you taken to minimize the COVID-19 spread through:
  • Human contact
  • Computer equipment
  • Shared office spaces
  • Common areas
• How do you determine “non-essential” personnel that should not have access to your facility?
• What is your contingency plan if/when travel or access is restricted?
• How can you keep normal work efficiency for these “non-essential” personnel working offsite?
• What kind of resources do you need to work offsite?

Did you know, OSHA does not allow block valves on the inlet of relief valves installed on air receivers in compressed air systems?

OSHA CFR 1910.169(b)(3)(ii) states, “No valve of any type shall be placed between the air receiver and its safety valve or valves.”

Did you know, relief devices that protect process pipe may be set to open above the piping design pressure?

Per ASME B31.3-2016, Sections 322.6.3. (see Figure 1) and 302.2.4 (f) (see Figure 2), a thermal relief valve may be set up to 120% of the design pressure of the protected system with the owner’s approval, as long as, the allowable accumulation criteria in 302.2.4.(f) are met. Set pressures lower than 120% of the design pressure may be required depending on the allowable accumulation pressures in 302.2.4 (f).

"Great teamwork is the only way we create the breakthroughs that define our careers."

As we enter 2020, most of us have already taken a moment to reflect on last year's successes and failures. (At least on a personal level.) A somewhat painful and unavoidable exercise to help guide your decisions in the upcoming year.

However, how many have taken stock of our past decade's personal successes and failures?

If you haven't, quickly give it a shot right now.

We are excited to announce Mr. John Burgess will be presenting "The Unintended Consequences of Relief Device Pipe Modification" at tomorrow's REMBE's Safety Conference.

REMBE^® Process Safety Days is a two-day networking event with highly topical presentations, live demonstration and an extraordinary evening event. It is dedicated to engineers, planners, operators, technicians, maintainer, safety inspectors, technical experts and inspection personnel in supervising organisations.

Establishing and maintaining an effective safety culture is a symphony of challenges and moving pieces.

Too often, those responsible engineers are stretched thin with competing priorities. Smith & Burgess is here to help. Our culmination of Process Safety knowledge enables us to quickly provide our clients with practical solutions that lead to compliance, significant cost-savings, and of course, peak facility safety.

Pressure relief systems and devices are used to prevent equipment and pipework from over-pressurization which can lead to mechanical failure and associated release of containment.

In order to function correctly, relief systems need to be properly designed to recognized standards, correctly installed and properly maintained. Changes to associated plant and pipework also need to be appropriately managed; often, seemingly unrelated changes can have an impact on the relief case of the system and render it incapable of protecting the system as designed. This is seen particularly on older plants with poor change management history.

The following list provides some details on the areas you should focus on when improving the quality of your Relief Validation Study.

Ms. Amanda Mueller  |  Process Safety Consultant

Ms. Mueller is a graduate from the University of Missouri with a degree in Chemical Engineering. She has extensive experience with Relief Systems and Flare Design projects. Over the past three years, Amanda has been an invaluable addition to Smith & Burgess' engineering staff and consistently exhibits the firm's dedication to quality process safety management.

The Opportunity:

A major United States Refinery hired Smith & Burgess to perform a site-wide revalidation.

The Opportunity:

A major US refinery used a competing engineering contractor to perform a flare and relief systems analysis. Upon completion of the project, the refinery was left with a list of facility upgrades that management deemed excessive. Smith & Burgess was hired to review the relief and flare systems documentation and provide engineering solutions that met corporate and industry requirements.

The Opportunity:

A recent audit of a “rebuild” design package for a major Asian gas plant identified that the EPC may have failed to follow company or industry standards. The owner needed an engineering review of the entire facilities’ relief systems designs prior to their start up in two months. Any deficiencies in company or industry standards needed to be addressed prior to the facilities’ start up.