Large gas duct flap valve has double expanding seal forming gas lock

摘要

The passage through a large gas duct is closed off by a flap surrounded by two surrounding metal batten seals (8a,8b) with transverse expanding seals. When the flap (13) is closed, the two sets of seals form a gas lock (15) between them. The metal batten seals within the gas lock have tension-relaxing slots (26-29) in the join zone to the flap cover, operating together with the transverse expanding seals (21,22) in the metal batten seals longitudinal axis.