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By making engineering insights easy to access and apply, Sustech helps create lasting value for the whole industry.

When Reliability Fails – Even in a New Plant

Heat exchanger leaks are typically associated with aging plants. But this tale is different. It happened in a brand-new facility. t shows why having reliable engineering support is key to avoiding costly surprises.

In the beginning …

At a newly commissioned gas plant, a recurring issue with the Amine Plate Heat Exchanger began to surface. Initially, the unit started leaking, leading to plate corrosion and a full plant shutdown. Maintenance teams cleaned the plates and replaced the gaskets, and operations resumed temporarily.

Within months, the same problem reappeared. Once again, the plant was forced to shut down, incurring substantial downtime costs. The cycle of cleaning, gasket replacement, and restarting was repeated only for the heat exchanger to fail yet again.

Each shutdown cost the operator millions in lost production and maintenance. Frustrated, the operator reached out to the equipment vendor for a resolution. However, the vendor denied responsibility, stating that the model in question had been in widespread use across the industry without similar issues reported elsewhere.

We Received the Call
When the operators faced repeated shutdowns, they made a smart decision and they brought in independent third-party engineers. Our role was to thoroughly investigate the defects in the plate heat exchanger and, if necessary, perform Finite Element Analysis (FEA) to validate the findings.
With the plant already in its fourth shutdown, time was critical. A fast, effective solution was essential to prevent further leaks and minimize revenue loss.
On-Site Investigation
We visited the site to closely inspect the heat exchanger, focusing on the condition of the plates and gaskets. Alongside gathering first-hand information, we reviewed the overall plant operation to understand the context.
Upon dismantling, we observed corroded plates and torn gaskets within the Plate Heat Exchanger. However, the Mechanical Data Report (MDR) confirmed that installation was carried out correctly, and the maintenance logs showed proper torqueing of the heat exchanger bolts.
The exchanger plates were stainless steel, and the gaskets were rubber, matching the MDR specifications. Operational logs revealed no significant pressure or temperature spikes, nor excessive flow conditions.
Interviews with operators indicated that leaks would begin within days of startup and progressively worsen over time. The gaskets and some plates had been replaced according to the OEM specifications.
While reviewing the piping layout on site, we discovered that the first pipe support upstream of the heat exchanger was fully restrained on all sides, a detail that raised suspicion.
Our Analysis
After careful consideration of our findings, we concluded:
- The heat exchanger, selected and installed according to API 662, was suitable from a process perspective.
- Materials used were certified to EN10204 standards.
- Process data showed no flow-induced forces affecting the unit.
Given this, we identified the piping as the root cause. Pipe stress analysis, performed per ASME B31.3 for the existing configuration, revealed that induced forces and moments were being fully transmitted to the heat exchanger nozzles. This excessive loading distorted the heat exchanger body, compromising its structural integrity.
The liquid found capillary paths through the gaskets, corroding surfaces not designed to be exposed, and ultimately leaking through the plates.
The key issue was the axial restraint of pipes at the first support, which imposed loads exceeding the allowable limits of the heat exchanger nozzles. This problem went unnoticed initially because the original stress analysis lacked load confirmation from the heat exchanger vendor.
Our Solution
To restore reliable operation and eliminate recurring leaks, we recommended:
- Removing axial restraints (guides) on pipe supports at all first supports upstream of the heat exchanger nozzles.
- Installing Teflon pads beneath pipe supports, secured with countersunk screws to the baseplate, to allow controlled pipe movement.
- Marking the pad position to monitor movement and conducting regular inspections to assess pad condition.
- Modifying certain support locations and types at both the heat exchanger and air cooler ends to comply with allowable nozzle load requirements per API 662 standards.
A Successful Outcome
Thanks to our thorough investigation and engineering recommendations, unplanned shutdowns were significantly reduced, improving plant availability. The owner avoided millions in potential losses — a testament to the value of expert, independent engineering support.
We’re proud to have contributed to this successful resolution.

Solution to Blown-out Steam Header

Several years ago, a significant incident occurred at a steel plant powerhouse involving the lead steam header of a low-pressure back pressure steam turbine, which detached at one end, releasing steam under pressure. Unfortunately, two plant operators lost their lives, and several others sustained injuries. Our team was engaged to conduct a thorough investigation.

The initial assessment by the owner’s engineering team identified a shear failure at the weld joint between the header and the endplate, attributed to 30 years of operation. However, this finding did not fully satisfy our technical review. We therefore undertook a more detailed analysis to determine the root cause of the failure.

Gathering Evidence
Our investigation began with collecting available documentation, including piping and building drawings. Unfortunately, the Material Data Reports (MDR), operational, and maintenance records were not available. However, valuable insight came from plant operators who reported hearing hammering noises emanating from the turbine lead steam header.
Our first-hand observations included:
- The curved endplate was fabricated from the same material as the pipe (DN250 ASTM A106 Gr.B).
- The failure was a shear along the weld line.
- Insulation was damaged in several areas, causing heat loss to the atmosphere.
- No steam trap or drain line was installed to remove condensate from the main line.
- The piping was supported by springs throughout, but one spring near the safety valves was locked, likely to prevent vibration.
Analysing the Evidence
The weld failure was evident, but given that the weld and endplate had performed reliably for 30 years, the root cause extended beyond the immediate failure. Key findings included:
- The endplate was cut from pipe material similar to the header, which is a non-compliant use of material. Its thickness was insufficient for an endplate designed under ASME B31.1 standards for 2000 kPa at 215°C.
- The reported hammering noise suggested the presence of saturated steam mixed with condensate, potentially causing steam hammer. The tattered insulation facilitated heat loss, encouraging condensate formation.
- Pipe stress analysis revealed thermal expansion caused the piping to sag, with the lowest point near a spring that had bottomed out. The locked spring near the safety valves acted as a rigid support, forcing downward piping growth and bending an elbow sufficiently to allow condensate to pool.
- This condensate accumulation restricted steam flow, producing the hammering noise. Eventually, excessive condensate caused the steam to forcefully escape through the weakest point — the endplate weld — resulting in failure.
Providing Solutions
Our technical recommendations included:
- Replace the end spool of the turbine lead header with a new pipe section and a butt-welded (BW) cap.
- Repair and properly insulate the piping to prevent heat loss.
- Install steam traps and condensate drains at identified low points, determined through pipe stress analysis.
- Relocate safety valves to optimize support and flow conditions.
- Reinstate spring support at the roof-top location and adjust spring support positions as necessary.
- Conduct non-destructive testing (NDT) on both new and existing weld joints.
Beyond design and installation improvements, we emphasized operational measures to prevent recurrence:
- Maintain comprehensive operational process data and a detailed maintenance log.
- Implement early reporting protocols for any deviations or anomalies observed by operators.
- Engage owner’s engineering specialists for modifications and organize regular third-party reviews for system health checks.
Averting Future Failures: Lessons Learned
This incident highlighted critical lessons at every project stage:
Project Management
- Ensure conservative and rigorous material management.
Design Phase
- Conduct thorough design and failure mode analysis.
- Incorporate foresight in design decisions.
- Utilize standard components and avoid design deviations under pressure.
Execution Phase
- Contractors must adhere strictly to design specifications.
- Quality inspectors should perform detailed and thorough reviews.
Commissioning
- Review design and safety reports comprehensively.
- Complete all punch list items satisfactorily.
- Verify Material Data Reports (MDR) carefully.
Operations Phase
- Provide operators with detailed knowledge of the process fluid.
- Retain and analyze operational and maintenance data consistently.
- Maintain a rigorous maintenance schedule.
- Prohibit modifications without designer approval.
The methodology for successful project delivery is well-established and must be followed meticulously. Any shortcuts or unauthorized deviations risk catastrophic failure immediately or in the future.

100 years of the BPVC code

“A Century of Safety” – The title of the ASME article celebrating the centenary of the BPVC (Boiler and Pressure Vessel Code). The BPVC is the mother of all American codes. The existence of this code and its derivatives mean that the engineering industry is a much safer place. Perhaps we should take some time to thank the people who made and contributed to the codes. These are people, famous as well as ordinary, who have charted the territory which we as engineers of today can confidently navigate. We are greatly indebted to these forefathers of our profession and hats off to people behind BPVC and all other engineering codes around the world, like our own AS2885 or the international ISO14692, ASME B31.1, B31.3, B31.8 and many others.

Here are a few lines from the article published by ASME that will give you a bit of taste of history:
“When ASME’s founders—including Henry R. Worthington, Alexander Lyman Holley and John Edson Sweet, along with other prominent industrialists and technical innovators of the nineteenth century— gathered in New York City for the first time in 1880, the main topic of discussion centred on the need for standardized tools and machine parts as well as uniform work practices in the dawning industrial age. Engineering standards, the founders agreed, would ensure safety, reliability and operational efficiency in machine design and mechanical production.
ASME issued its first standard, Code for the Conduct of Trials of Steam Boilers, in 1884. This paper evolved into Rules for the Construction of Stationary Boilers and for Allowable Working Pressure—the first edition of ASME’s now-legendary Boiler and Pressure Vessel Code (BPVC)—issued in 1914 and published in 1915.”
It has been a long way since. By far the BPVC has done its job right in standardising designs, building safety into design, preventing the loss of lives and harm to environment and property.
But what exactly is a code? Put simply, it is a book where all the collective engineering experience and knowledge is compiled to “ensure safety, reliability and operational efficiency.” But a book is useful only as long as it is read. So the legislation has instilled regulation and our profession implements those through internal review, peer review, safety in design review, HAZOP, independent third party review, design verification, MDR validation and code compliance. When these processes are followed diligently with the assistance of the right people, the result is a much safer and productive installation, low on maintenance and high on availability, therefore high on profitability.
There was a popular phrase till a few decades ago: There is no royal road to education. Similarly there is no short cut to safety. Given the scale of industrialisation that has happened throughout the world, and the new heights that technology has scaled we know that we have achieved greater safety standards than hundred years before. But the goal of zero harm is yet to be reached.
We have heard of Chernobyl, 3 mile Island, Deep water horizon, Fukushima Daichi, Varanus Island and Pike River. The memories of these incidents make us think and rethink our role as engineers. Every time an industrial incident happens anywhere in the world, as engineers we ask, why did this happen? Could this have been averted? What can we do to prevent accidents like this in the future? Then when we get the opportunity to do a root cause analysis, we use the same process of questioning to find the cause to prevent future recurrence. That’s our duty of care. From my experience of two decades of engineering, the lesson I learnt is to abide by the code to make a safe and efficient installation. I learnt to enhance and bring clarification to the code and to raise awareness about codes such as the BPVC and their purpose to make societies and communities safer.