Shut-off valve for pneumatic fender

1. A shut-off valve installed in an accommodation chamber regulating entry/exit of air, the shut-off valve comprising:

a body removably disposed in the accommodation chamber and having multiple air passage holes;

a valve stem adapted to be vertically moved along a valve stem insertion hole formed in the body;

a disc mounted on a disc engagement portion formed at a lower end of the valve stem to open/close at least one of the multiple air passage holes;

a rotor disposed on an upper side of the body to vertically move the valve stem, the rotor comprising an opening/closing indicator to check opening/closing of the shut-off valve outside the accommodation chamber,

wherein the accommodation chamber has an upper wall, a lower wall, and a side wall; the body is disposed to pass through the upper wall and the lower wall of the accommodation chamber; and the disc is located outside the accommodation chamber.

2. The shut-off valve according to claim 1 , further comprising:

a protrusion plate extending from the lower wall,

wherein an extension length of the protrusion plate from the lower wall is greater than or equal to a distance from a lowermost portion of the shut-off valve to the lower wall upon opening of the shut-off valve.

3. The shut-off valve according to claim 1 , wherein the body comprises:

a body protrusion formed at a lower portion of the body to secure the body to the lower wall of the accommodation chamber;

a body protrusion O-ring insertion portion recessed in the body protrusion to receive a body protrusion O-ring, the body protrusion O-ring being adapted to improve air tightness between the accommodation chamber and the body; and

a seat contacting the disc, the disc having an inclined section on an outer surface thereof and comprising a disc pressing member disposed in the inclined section to contact a lower side of the seat such that the disc does not directly contact the accommodation chamber upon opening/closing of the shut-off valve.

4. The shut-off valve according to claim 3 , wherein the multiple air passage holes comprise a longitudinal air passage hole and a transverse air passage hole, and the disc opens/closes the longitudinal air passage hole.

5. The shut-off valve according to claim 1 , further comprising:

a hollow bushing disposed on the body and having a bushing flange protruding outward;

a hollow cover disposed on the bushing and having a cover flange protruding outward;

a first bolt tightly securing the body, the bushing, and the cover to one another; and

a second bolt tightly securing the bushing to the body,

wherein a bolt head of the first bolt is seated on the cover flange to apply fastening force and a bolt head of the second bolt is seated on a second bolt head-seating portion to apply fastening force, the second bolt head-seating portion being recessed in the bushing flange.

6. The shut-off valve according to claim 5 , wherein the rotor comprises:

a rotational portion imparting torque to the rotor;

a support portion extending downward from the rotational portion to improve durability of the rotor, the support portion having a larger thickness than the rotational portion; and

a rotor flange extending downward from the support portion to be seated on the body, the rotor flange having a larger thickness than the support portion, and

wherein the cover flange presses at least a portion of the support portion in a direction in which the first bolt applies pressing force.

7. The shut-off valve according to claim 6 , wherein the bushing comprises a bushing protrusion protruding downward from the bushing flange and pressing at least a portion of the rotor flange in a direction in which the second bolt applies pressing force.

8. The shut-off valve according to claim 7 , wherein the body further comprises:

a body flange laterally protruding from the body and disposed on the upper wall of the accommodation chamber; and

a rotor seating groove recessed in the body flange and allowing the rotor flange to be seated thereon,

wherein a depth of the rotor seating groove is greater by 0.05 mm to 1 mm than the sum of heights of the rotor flange and the bushing protrusion, the heights being defined with respect to a longitudinal direction of the body.

9. The shut-off valve according to claim 1 , wherein the valve stem comprises:

an axial portion extending in a longitudinal direction of the body; and

a male screw formed on an upper side of the axial portion,

wherein the rotor comprises a female screw having a predetermined radius with respect to a central axis thereof to be engaged with the male screw, the female screw extending to a predetermined height of the rotational portion through the rotor flange such that the valve stem is vertically moved by rotation of the rotor.

10. The shut-off valve according to claim 9 , wherein, upon rotation of the rotor, the disc coupled to the disc engagement portion under the axial portion is vertically moved to open/close at least some of the multiple air passage holes.

11. The shut-off valve according to claim 9 , wherein the valve stem further comprises a key protruding from the axial portion, and the body further comprises a key groove formed under the rotor seating groove to guide insertion of the key such that the valve stem is prevented from rotating upon rotation of the rotor.

12. A method for checking opening/closing of the shut-off valve according to claim 9 , wherein opening/closing of the shut-off valve is checked outside the accommodation chamber based on information on position of the male screw, the information being obtained through the opening/closing indicator.