Expansion valve

An expansion valve comprising:

• a valve main body comprising a valve chamber and a valve seat;
• a valve body configured to limit passage of a fluid by being seated on the valve seat and allow passage of the fluid by separating from the valve seat;
• a coil spring configured to urge the valve body toward the valve seat;
• and
• an actuation rod configured to press the valve body toward a direction separating from the valve seat against an urging force applied from the coil spring,
• wherein the valve chamber comprises a cylindrical inner wall being connected to the valve seat,
• the valve body comprises a contact portion configured to be seated on the valve seat and a body portion having a tubular shape facing the inner wall,
• in a cross section taken in a direction orthogonal to an axis of the valve body, a shape of an inner circumference of the inner wall differs from a shape of an outer circumference of the body portion, so that a space through which the fluid passes is formed between the inner wall and the body portion, and the inner circumference of the inner wall and the outer circumference of the body portion are partially slidably in contact with each other,
• bubbles in the fluid are collapsed when the fluid passes through the space formed between the inner wall and the body portion, and
• the fluid passes the valve seat after passing through the space formed between the inner wall and the body portion.