Thermal stress can wreak havoc on a valve, causing cracks and potentially failure. MOGAS, with one of its business partners, has developed a thermal sleeve that eliminates this potential catastrophe.

The development of the thermal sleeve came as a result of one of MOGAS’ customers experiencing cracking in a catalyst handling valve. The thermal stress had been noticed a few years ago, but it was not until the customer pulled the valve out of service and opened it that it was determined that a better solution to address the problem.

The valve had been going through extreme thermal cycles – 122 F/ 50 C to over 752 F / 400 C – MOGAS engineers determined it would be beneficial to design a sleeve that would be placed inside the valve that could then keep the extreme thermal changes from affecting the valve itself.

The ceramic sleeve, which is patent pending, is created by spraying a ceramic material onto a metal sleeve. The sleeve is then placed within a valve that has been heated up to 1000 F / 537 C. Once the sleeve is inserted, the valve is allowed to cool and as it does it compresses the ceramic sleeve within the valve. The compressive strength keeps the ceramic intact.

Ceramic is used because it is not very conductive, unlike metal.

“The ceramic thermal sleeve protects the valve by distributing the heat evenly along the body to avoid high stress points that could cause cracking,” says Wes Barrett, global hydrocarbons manager for MOGAS Industries.

The sleeves run from the nozzle of the reactor to the catalyst cooling drums. Right now, the sleeves are ideal for catalyst handling systems in H-Oil and LC FINING units. H-Oil is an ebullated bed process for upgrading atmospheric and vacuum residues, and is a process license from Axens NA. LC FINING is a process under the licensor Chevron Lummus Global (CLG) that also is involved in the ebullated bed process that handles petroleum bottoms and other heavy hydrocarbons for purification or conversion to distillate.

“The ceramic coating doesn’t conduct heat across the valve member. It absorbs heat and is not conductive so the adjacent material is kept from the full heat source,” says Vinh Nguyen, director of technology/research and development for MOGAS.

Tags: MOGAS Industries