Pressure reduction valve

A pressure reduction valve comprising an outer member and an inner member disposed inside the outer member, wherein

• the outer member comprises a valve seat portion having an opening which allows a fluid to flow therethrough, and an outer tubular portion extending tubularly from the valve seat portion,
• the inner member comprises a valve body portion which opens and closes the opening, and an inner tubular portion extending tubularly from the valve body portion and disposed inside the outer tubular portion,
• the inner tubular portion comprises a first end portion located at a valve body-side end, a second end portion located at an end opposite to the valve body portion, and a middle portion located between the first end portion and the second end portion,
• an outer surface of the inner tubular portion in the middle portion is recessed inward in a radial direction of the inner tubular portion over an entire periphery of the inner tubular portion, and
• a distance between the outer surface of the inner tubular portion in the middle portion and an inner surface of the outer tubular portion is greater than a distance between the outer surface of the inner tubular portion in the first end portion and the inner surface of the outer tubular portion and greater than a distance between the outer surface of the inner tubular portion in the second end portion and the inner surface of the outer tubular portion.