These vent stacks are manufactured from durable galvanized mild steel to a height of 2 metres, specifying a discharge exit velocity of 30m/sec at 2 metres above deck and with use with either the VP1350W or VP1500WS Gas Freeing Fan. They comply with SOLAS chapter 59 paragraph 2 which specifies an exit velocity of 30m/s at 2m above the deck.