DIN 7079-1 Bb.2:1996 Pressure resistant circular glass-to-metal fused sight glasses - Part 1: For holders with recess; design steel; operating temperatures -30 °C and -60 °C
2015DIN 7079-1:2015-10 Pressure resistant circular glass-to-metal fused sight glasses - Part 1: For holders with recess
2015DIN 7079-1:2015 Pressure resistant circular glass-to-metal fused sight glasses - Part 1: For holders with recess
1999DIN 7079-1:1999 Pressure resistant circular glass-to-metal fused sight glasses - Part 1: For holders with recess
1996DIN 7079-1 Bb.2:1996 Pressure resistant circular glass-to-metal fused sight glasses - Part 1: For holders with recess; design steel; operating temperatures -30 °C and -60 °C