2011DIN 21632:2011-03 Air regulating systems for mining - Wing air doors for haulage tracks - One-wing type air doors without pressure reduction / Note: DIN 21632 (1993-01) remains valid alongside this standard until 2011-08-31.
2011DIN 21632:2011 Air regulating systems for mining - Wing air doors for haulage tracks - One-wing type air doors without pressure reduction
1993DIN 21632:1993 Air regulating systems in mining; wing air doors for haulage tracks; one-wing type doors without pressure reduction