Decision tools for selecting stem sealings according to the demands of TA Luft (edition 2002): Part 2: Continued from Valve World October 2006

摘要

Executing the test for verifying the equality of sealing systems Every commercial helium leakage detector may come to use. Test medium: helium; Molar masse: 0,004kg/mol; Dynamic: viscosity (0℃) 18,7 uPa s; Test temperature: < 250℃ and > 250℃;Application temperature: < 250℃ and > 250℃;With detectors for the helium leakage test, reading is taken in mbarl/s. In VDI 2440 [3], the maximum permissible value of leakage rate is presented in mbarl/(s{sup}*m). For this reason, the leakage rate that can be tolerated must be determined in advance. The leakage rate refers to the diameter of the stem.