A louver type blast valve making use of an aerodynamically configured blade, independently activated by air flow to block a blast shock wave and a subsequent return suction wave. The blast valve (FIG. 6) including a frame and at least one aerodynamically configured blade, independently activated by air flow to block a blast shock and a potentially following return wave. The aerodynamically configured blade having an elongated shape, including at least a steep convex surface and a flat or shallow concave surface, forming a leading edge and a trailing edge at the intersection of the surfaces. The blade being hinged to the frame about a longitudinal axis passing between the steep convex surface and the flat or shallow concave surface.

A non-return device, for example, for a crude gas line, comprises a housing, a seat, arranged in the housing, and a flap that is pivotably attached in the housing and rests on the seat in a closed state of the non-return device and is lifted off of the seat in an open state of the non-return device. The flap comprises at least one flexible connecting element on the housing, with a first end region of the connecting element being attached to the housing and with a second end region of the connecting element being attached to the flap.

A louver type blast valve making use of an aerodynamically configured blade, independently activated by air flow to block a blast shock wave and a subsequent return suction wave. The blast valve (FIG. 6) including a frame and at least one aerodynamically configured blade, independently activated by air flow to block a blast shock and a potentially following return wave. The aerodynamically configured blade having an elongated shape, including at least a steep convex surface and a flat or shallow concave surface, forming a leading edge and a trailing edge at the intersection of the surfaces. The blade being hinged to the frame about a longitudinal axis passing between the steep convex surface and the flat or shallow concave surface.

A pressure/vacuum relief system having one or more pressure relief/vacuum valve assemblies disposed within the controlled atmosphere room and a vent pipe to provide two-way fluid communication between the relief valve assembly and the outside environment. The relief valve assembly may be a split valve arrangement that includes a pressure valve that opens in response to positive pressure in the controlled atmosphere room and a vacuum valve that opens response to negative pressure in the controlled atmosphere room. The pressure and vacuum valves may be incorporated into a single valve body on opposite sides of a shared chamber that is coupled to the vent pipe. In one embodiment, the vent pipe is fitted through an external wall of the controlled atmosphere room.

An antiknock valve with both sides resisting a shock wave, and a valve body thereof. The antiknock valve includes a valve core (200) and two valve bodies (A3, A4). The valve body (A3/A4) includes a frame body (101/102), wherein two intersected supporters(2a, 2b/3a) are provided in the frame body (101/102) in a symmetrical manner, the supporters (2a, 2b/3a, 3b) intersect on a ridge-shaped column (2d/3d) and openings(2c1/3c2) are provided at intervals along the direction of the ridge-shaped column (2d/3d). The valve cores (200) are located above the openings (2c1/3c2) and the two valve bodies (A3, A4) are engaged and fixed; and one end of the valve core (200) is rotatably connected on the ridge-shaped column (2d/3d). Since the antiknock valve reduces the weight of the valve core (200), the antiknock capacity is improved, a closing speed is increases, and the antiknock valve is safer.