- for gas test standpipe - safe device to prevent flame breakthrough into gas pipeline or gas tank, appoved for any explosive gases, including hydrogen - brass-made adapter with 2 1/2 internal thread/ext. thread (with sealings) for direct connection to the gas test standpipe - IBExU 09 ATEX 2019 X, - explosion group IIA1, IIA, IIB1, IIB2, IIB3, IIB, IIC - according to DIN EN ISO 16852 - ATEX- Nr. / Typ : IBExU 20 ATEX 2115 X / DEF