Site Network: Main Site | Mail Access | Site Map


Hopper Engineering Associates has been active in the petrochemical industry since the early 1980's. Our clientele includes refineries, offshore platforms, pipeline and distribution facilities, chemical plants and equipment manufacturers. The company offers a diverse project history and team of experienced engineers.

Petrochemical Industry In Depth:

Hopper Engineering Associates provides multidisciplinary civil, structural and mechanical engineering support to the petrochemical industry. Our focus is in solving the specialty non-commodity engineering issues faced by facility operators and manufacturers. In addition to supporting facility upkeep, we provide immediate engineering support as required during turnarounds. We have extensive experience helping to extend the service life of aging equipment and structures. We also maintain an in-house QC program and make safety a priority. All of our staff are safety trained and current in the LARSO program.

The following project examples summarize our experience, however, are in no way comprehensive of our expertise. Please direct specific questions regarding project experience to Christine Jacobs, Principal.

Featured Projects:

Petrochemical ProjectsA 70-ton valve used to automatically open the bottom head of a coke drum had to be supported from the existing concrete pedestal. HEA designed a support system capable of accommodating vessel thermal motions, seismic loads and maintenance activities, while remaining within a small space and minimizing interference.

Petrochemical ProjectsA rig in the Cook Inlet fleet was to be requalified for service by analysis for a 1000 year return period quake. HEA developed a finite element model to represent the platform, which accounted for the complex interaction between the drill pipe setback and the drilling rig structure during a seismic event. Weak structural elements were identified and reinforced.

Petrochemical ProjectsNew coke drums, which are larger than the existing ones, were to be installed. The table top support structure was also experiencing spalling of concrete on the underside as illustrated in the picture. HEA performed a dynamic analysis of the structure and drums and designed a refurbishment.

Petrochemical ProjectsA J-tube previously used as a firewater source, located in a leg of an oil platform, was found to be plugged. A systems upgrade to the fire protection system requires a functional fire water pump at the leg. Flooding of the leg was under consideration as a solution. HEA generated a 3D model of the leg to visualize fluid flow in the hypothetically flooded leg.

Petrochemical ProjectsMultiple cracking and leak failures have occurred in tubing located within an oil refinery economizer. Metallurgical examination of the failed tubes indicates that corrosion fatigue is the most likely failure mechanism. HEA performed a finite element analysis and found that restrained thermal expansion stresses caused by tube binding were the most likely source of fatigue stresses. Tubing support modifications were suggested to reduce thermal expansion stresses.

Petrochemical ProjectsThe ultimate capacity of an existing outlet collector needed to be determined. HEA generated a finite element model of the outlet collector and a differential pressure load was applied. Our analysis considered material plasticity to find the ultimate collapse load. An improved design that incorporated a center support ring and thicker plates was recommended.

Petrochemical ProjectsIce severely damaged a horizontal brace of an oil platform jacket structure. HEA was tasked to determine the platform's fitness for service and remaining life. HEA analyzed the local and global stresses associated with the observed damage. Global elastic analysis of the platform jacket structure and local non-linear analysis of the horizontal brace were performed, taking into account ice and earthquake loading. Repairs were suggested to increase service life.

Petrochemical ProjectsThe stability of a drilling platform, currently in the feasibility phase of development, is in question. The platform is supported by three composite legs embedded in the sea floor. The platform supports significant load from a drilling rig, drill pipe setback, structures and equipment. HEA analyzed the platform for a severe earthquake lasting over 44 seconds and found it to be stable.

Petrochemical ProjectsThe cause of repeated cracking in the welded connection of a pipe stub from an 8" line to a bleeder valve was unknown. HEA attributed the failure to high fatigue stresses caused by resonant vibration of the valve. This vibration was traced to pressure pulsations in the 8" line. HEA recommended changing the size and location of the valve, which was implemented successfully.

Petrochemical ProjectsA pipeline on the north slope was found to be dented during an inspection. HEA evaluated the pipe using finite element analysis. The results of our analysis were used to determine the additional risk resulting from the dent and the pipe's remaining service life.

Petrochemical ProjectsA local refinery has requested an inspection of their secondary steel structures at their facility. The objective of this inspection program is to ensure that the safety of personnel who use these facilities is maintained. HEA developed inspection criteria and then generated data sheets for recording the observed issue, location of the issue and the suggested remediation.

Petrochemical ProjectsHEA developed a process by which an offshore oil platform operator could minimize the risks to human safety and the environment from possible equipment or structural failure. HEA performed topside surveys and devised a program to screen and rank structural and equipment items on the likelihood and probable consequences of failure. We based the rankings on visual inspections, failure history, crew interviews, analytical evaluations, and NDE.

Petrochemical ProjectsThis facility has a number of vessels, tanks, pipes and equipment containing Regulated Substances (RSes) as identified in the The California Accidental Release Program (Cal ARP). HEA helped to prepare and revalidate this facility's Risk Management Plan (RMP) with particular focus on the seismic assessment. A risk based approach was used to refine the inspection work scope. As is typical, a few minor deficiencies, such as missing nuts and cut braces, were found and corrected (by others). A report documenting the findings and corrective action was provided to the client. Note: At the request of industry, HEA helped draft the original "Guidance for Cal ARP Seismic Assessment" document in 1999.

Additional Spotlight Projects:

Below you will find additional Petrochemical related projects we have worked on.