In severe service environments, such as the transfer of catalyst from an ebullated bed reactor, isolation valves are often subjected to frequent and extreme temperature and pressure cycles. This causes premature thermal fatigue stress cracking in valves, which are also be subject to erosion from the abrasive nature of the catalyst.
MOGAS' newly patented tubular member with thermal sleeve liner is effective to inhibit thermal fatigue stress cracking in the end connector near the seat—the area of most concern. Comparative finite element analysis studies revealed that a valve without MOGAS' patented sleeve in such severe environments reached a peak stress intensity at the end connector at 841 MPa. According to ASME's fatigue design curve, this valve's design life would be 50 to 200 cycles. Under the same conditions, and employing MOGAS' patented sleeve, the peak stress intensity was reduced to 321 MPa (46.6 ksi), which would result in a valve design life of at least 30,000 cycles.
Download our data sheet for more information: Thermal Sleeves in C-Series Valves