Process Engineering | Overpressure Problems?  – Reduce Your Liability with Preventative Safety Measures

In today’s society, we strive vehemently to achieve the maximum profitability in our chemical production facilities; in most cases, company profits are directly connected to the throughput of its material processing equipment. During the engineering design phase of a production facility, the throughput of equipment is usually established. When uncertain, because true engineering is managing or eliminating uncertainty, engineers have an inclination to leave a bit of “headroom” in the design capacity of equipment when financially feasible; this typically leaves space in the operation of the unit to work out any unforeseen errors. After the equipment is up and running with stability, occasionally, this “headroom” can be tapped for increases in production, consequentially profits.

Increases in plant production rates without the extensive examination of the relief systems can subsequently lead to a lack of compliance with industry recommended practices, furthermore, and more seriously, a reportable safety incident. Actions as small as an increase in pump size or minor increases in plant air pressure and capacity can lead to reportable incidents and the rupture of pressure vessels. Frequent reports show that actions that increased production capacity did not always accompany noticeable increases operating pressure when measurements were taken at steady state; moreover, a few of the systems ran for years without any overpressure problems at all.

For example, one particular facility, after years of operation, experienced a major process upset, as a result, the system failed in a completely closed outlet situation. The system was properly designed to fail in this state to prevent other catastrophic consequences downstream; however, the increase in production rate exceeded the relief valve maximum capacity, forcing the vessel to rupture at the bottom seam, relieving the excess material to a personnel occupied control room. No employees were hurt as a result of the incident; on the other hand, the facility suffered a lengthy shutdown, the vessel required replacement, and the control room had to be refitted with new equipment. In addition to the damage created by the relief incident, a thorough examination of the relief system still had to be conducted, as well as, a new relief valve specified and purchased with a larger capacity.

Establish a sustainable and safe operating work place with the addition of an annual or biannual evaluation on each of your relief systems. When examinations of your relief systems are conducted, more than safety concerns are addressed; during these examinations, debottlenecking ideas frequently come about along with other potentially profitable ideas. The benefits are endless, and in the worst case, you have protected your investments and your employees. Throughout the chemical process industry, questions arise on whether or not to invest in an extensive relief device maintenance and evaluation program; the more imperative question is, “can we afford not to invest money into our safety systems protecting our assets and our people”. Setting a new standard is not easy; in spite of the intricacies, benefits will arise, profit loses will be minimized, and safety will be at the forefront of your company.

Key Engineering, Inc. (KEY) has the expertise to analyze and modify your existing relief systems.  We take pride in our twenty-two point relief analysis that provides safety and reassurance to our customers.  KEY’s engineers are available on demand with the practical experience to discuss and explain the problems potentially affecting your relief systems.  Have your relief system accurately analyzed with flow modeling software and precise chemical properties using a pragmatic design approach that is tried and true.  Our process engineering division takes considerable care in the evaluation of relief systems.  Your project will have a dedicated Alabama licensed professional engineer performing the rigorous calculations required to ensure employee and asset protection.  KEY has access to the most contemporary codes and regulations recommended by the chemical process industries.  Contact us and our experienced team will be happy to discuss any of your process safety concerns. – Jeremy K. Jarmon, P.E.