TA-Luft TA-Luft only deals with stem sealing area. Also, no third party witness is needed. The TA-Luft test qualifies only a “high-quality sealing system”. TA-Luft is considered to be complied with if metal bellows with a safety energised packing or similar sealing systems are used; as per VDI 2440. TA-Luft does not specify the number […]