Grayloc® Connectors Survive High-Pressure Hydrogen Fire with Sealing Integrity Intact

A gas leak caused a small but intense fire in a large petrochemical facility where Grayloc connectors were used throughout the system. During the post-incident inspection, it was established that the connectors maintained their sealing integrity despite exposure to temperatures ranging from 2,000°F to 3,000°F (1090°C to 1650°C).

The gas leak, traced to an external packing gland, occurred in the hydrogen processing unit, which contained 80% hydrogen gas operating at 6,000 psi (414 bar) and 500°F (260°C). At this pressure and temperature, hydrogen gas will auto-ignite when exposed to atmospheric conditions.

Grayloc® connectors are commonly used in critical service applications. They meet the operating criteria of high-pressure and high-temperature applications and the requirements for leak-free functionality thanks to their metal sealing technology. Grayloc connectors were used throughout the entire hydrogen processing piping system, and the system’s valves incorporated Grayloc ends. The majority of the connectors had carbon steel hubs, clamps, and bolting, and included stainless steel seal rings (AISI 630).

Case Study Grayloc Connectors Survive High Pressure Hydrogen Fire With Sealing Integrity Intact 1

The photograph shows the level just above the leaking valve packing gland, within 15 ft (4.5 m) of the main reactor vessel.

The intense heat destroyed three control valves; their operator housings were melted and their control functions were completely lost. These valves, installed with Grayloc connectors, were within 2 ft (.6 m) of the melted operators. The Grayloc clamps provided the only structural support for the valves, and close inspection revealed that the connectors neither leaked nor loosened.

No pipe connector can be guaranteed to survive extreme temperature exposures, as detailed above, but this experience has demonstrated that Grayloc connectors provide extra margins of structural safety over bolted flange piping connectors. If a bolted flange was used, the excessive heat would have likely resulted in bolt relaxation and a subsequent leak. The nature of the Grayloc clamp configuration meant it was less likely that a preload on the joint would be lost. A conventional seal would have been more likely to leak when compared to the self-energized, pressure-enhanced Grayloc seal.

The customer expressed satisfaction with the integrity of the Grayloc connectors post-incident.

The customer was also able to reduce the downtime and expense required to replace and repair fire-damaged system components based on the Grayloc connectors’ ease of disassembly and reassembly. Most importantly, the customer avoided catastrophic results as the Grayloc connectors prevented a leak from occurring, thwarting any potential knock-on effects of the incident.

Ready to learn more?

Explore our Grayloc Products.

Contact Us

Contact Us | Grayloc® Connectors Survive High-Pressure Hydrogen Fire with Sealing Integrity Intact

Company page Since our founding in the early 1960s, Oceaneering has expanded and grown globally to service several industries such as the offshore energy industry, defense, entertainment, material handling, aerospace, science, and renewable energy industries. In 1964, Mike Hughes and Johnny Johnson formed a Gulf of Mexico diving company called World Wide Divers. The company grew in response to increasing demand for their services and in 1969 merged with two other diving companies to form Oceaneering International, Inc. To solve the toughest challenges, we do things differently, creatively, and smarter. As your trusted partner, our unmatched experience and truly innovative portfolio of technologies and solutions give us the flexibility to adapt and evolve, regardless of market conditions. Our mission is to solve the unsolvable. We thrive by creating industry-changing technically creative solutions for the most complex operational challenges under water, on land, and in space. Our five core values establish a common culture and demonstrate what is most important for us as a company. Since the beginning, the company has transformed from a small regional diving company into a global provider of engineered products and services. Today, we develop products and services for use throughout the lifecycle of an offshore oilfield, from drilling to decommissioning. We operate the world's premier fleet of work class ROVs. Additionally, we are a leader in offshore oilfield maintenance services, umbilicals, subsea hardware, and tooling. We also serve the aerospace, defense, and theme park industries. Underpinning everything we do, safety is not only the foundation of our core values, but it is vital to our unmatched performance record and company culture. The industries we serve are as diverse as they are complex. Whether we are engineering deepwater umbilicals or developing robotics for aerospace applications, the safety and health of our employees, vendors, and customers is an integral part of our day-to-day business. If we are working, then our responsibility is to be working safely. Since our inception in 1964, we have placed a high value on employee safety—from diving services and subsea inspection to vessel-based installation operations. We have and will continue to evolve not only our health, safety, and environmental (HSE) processes, but those of the industries in which we work. Although we have been fatality-free since 1999, our HSE journey goes beyond statistics. As our portfolio of services has grown, we have continued to prioritize and advance our approach to HSE.