Fuel cut off valve

A cut off valve that is to be attached to an upper portion of a fuel tank and opens and closes a connection conduit for connecting an inside of the tank to outside of the tank according to a fuel level in the fuel tank, the cut off valve comprising:

• a casing including
• (i) a first valve chamber that is connected to the inside of the fuel tank,
• (ii) a second valve chamber that is connected to the first valve chamber,
• (iii) a first connection conduit that connects the first valve chamber and the second valve chamber,
• (iv) a first seal part that is formed on an opening peripheral part of the first connection conduit,
• (v) a second connection conduit that connects the second valve chamber and the outside, and
• (vi) a second seal part that is formed on an opening peripheral part of the second connection conduit;
• a first valve mechanism, housed in the first valve chamber, that seats on the first seal part to close the first connection conduit when the fuel level reaches a first liquid level;
• a second valve mechanism, housed within the second valve chamber and seats on the second seal part to close the second connection conduit when the fuel level reaches a second liquid level, the second liquid level being higher than the first liquid level;
• and
• a restriction path, formed between the first valve chamber and the second valve chamber, that forms a path area that is smaller than the conduit area of the first connection conduit, so as to cause the pressure within the fuel tank to rise when the first valve mechanism seats on the first seal part.