Procedure and purpose of stretch test for electric butterfly valve tester
Place the electric butterfly valve on the multi-channel coordination testing machine or the train special electric butterfly valve testing machine, keep it at the design standard height, and fill it with compressed air to make it reach the standard load or internal pressure. Then, disconnect the air source and let it stand for more than 15min to allow full deformation, and start face testing after confirming that there is no obvious pressure drop. Slowly stretch or move laterally for 5 times within the maximum stroke, and check the maximum outer diameter during the Liutong test to see if there is abnormal deformation and air leakage during the test.
The purpose of the extension test is to ensure that the electric butterfly valve is stable in vertical tension and compression and lateral offset, and there will be no negative stiffness. Therefore, in order to ensure the stability of temperature during the test and reduce the impact of temperature changes on the test results, it is recommended to use a test speed of 10mm per minute.