Thermal Shock Test Rig for CNG Shut-off Valve

In Automobile, Gasoline Engines are being used along with electrically operated shut-off valve installed at the roof of bus in case of higher capacity of CNG systems. In order to start/ stop CNG supply from cylinder for running of engine/ safety/ servicing an electrical operated ignition switch/ key controlled CNG Shut-Off Valve is placed just after the cylinders. There have been few failures of these CNG shut-off valves in field application. On investigation, it was observed that the CNG shut-off valve gets failed due to water ingress in coils from the cracks on surface generated due to spray of water (due to daily washing of bus and rain) on heated shut-off valves. In order to validate this field failure and subsequent validation of modified design, a need was felt to use a test rig which can exactly simulate the water spray based thermal shocks. However, there was no low cost facility available to simulate the field service condition for validation. Therefore, a low cost test set-up was designed and developed to simulate the failure in test lab to analyze the failure and root cause analysis and further durability validation of improved design. The designed and developed test rig was very useful to investigate the root cause of failures and validation of improved samples. The test rig has been in operation for 2 years without any failures and has validated more than 30 samples of existing and improved samples. The test rig was designed and developed completely in-house and is a low cost in price as well as low running cost.