JP2581941Y2 - Check valve for cold regions - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve installed in a water supply pipe in a cold region, and more particularly, to a check valve for a cold region provided with a strainer.

[0002]

2. Description of the Related Art A check valve provided on a water supply pipe in a cold region is
In order to prevent freezing in winter or the like, water is drawn from the water supply pipe.

FIG. 2 is a longitudinal sectional view showing a conventional check valve for a cold district. A branch pipe portion 2 extends laterally from a lower portion of the substantially cylindrical valve casing 1, and an inflow port 3 is provided at an end of the branch pipe portion 2. An outlet 4 is provided at an upper portion of the valve casing 1. A valve seat portion 5 is provided in an inward flange shape at an intermediate portion in the vertical direction in the valve casing 1. A valve element 6 is provided so as to be able to move up and down so as to be seated from above on a seat surface 5a on the inner peripheral edge of the valve seat portion 5.

[0004] An arm 7 extends in a radial direction at an upper portion in the valve casing 1. A coil spring 8 is interposed between the arm 7 and the valve 6, and the valve 6 is urged downward.

[0005] A water outlet 9 is provided at a lower portion of the valve casing 1.

A push rod 10 extending in the direction of the axis of the cylinder of the valve casing 1 is inserted through the water outlet 9. Note that a flange 11 is provided in the middle of the push rod 10. An O-ring 12 is mounted on the outer peripheral surface of the flange 11. The O-ring 12 is in contact with the inner peripheral surface of the water outlet 9 in a watertight and slidable manner.

In this check valve, since the valve element 6 is seated on the valve seat surface 5a from above, only a forward flow upward in FIG. 2 is permitted, and the upper side (downstream side) of the valve element 6 is provided. Water is prevented from flowing back below the valve body 6.

When the push rod 10 is pushed up, the upper end of the push rod 10 pushes up the valve 6. Also,
The flange 11 is detached upward from the drain port 9.

As a result, the valve body 6 separates from the valve seat surface 5a and the drain port 9 is opened, so that water downstream of the valve body 6 flows out of the drain port 9 to drain water.

[0010]

SUMMARY OF THE INVENTION In the above-mentioned conventional check valve for a cold region, the strainer cannot be installed inside. That is, when the strainer is installed, the water remains so as to completely cover the strainer due to the surface tension of the water immediately before the end of drainage. When this residual water freezes, the entire strainer is covered with ice, and water does not flow even when the water supply pressure is applied.

[0011]

SUMMARY OF THE INVENTION A check valve for a cold district according to the present invention has a tubular valve casing having an inlet at a lower portion and an outlet at an upper portion, and a vertical direction in the valve casing. A valve seat portion provided with a seat surface facing upward, a valve body provided to be vertically movable so as to be seated on the valve seat portion from above, and the valve body in a seating direction. A non-return valve for cold districts having a biasing spring and a push rod having an upper end located directly below the valve body and a lower end extending out through a drain port at a lower portion of the valve casing; A strainer attached to the push rod below the valve seat portion, and the strainer abuts when the push rod is moved downward to separate a primary side and a secondary side of the strainer. Set a stopper It is characterized in that the.

[0012]

When the push rod is pushed up to drain the water in the cold check valve of the present invention, the valve body is pushed up by the push rod to drain the water.

In the present invention, at this time, the strainer is also moved upward together with the push rod. When the strainer moves upward, the strainer separates from the strainer stopper, and a gap is formed between the two. Therefore, all water above (downstream of) the strainer flows down through this gap. As a result, there is no or almost no residual water in the cold district check valve. Even if a small amount of water is frozen, when the water supply pressure is applied, the water flows in the forward flow direction, and the small amount of ice is quickly melted.

[0014]

An embodiment will be described below with reference to FIG.

In this embodiment, a strainer stopper 13 is provided below the valve seat 5 in the valve casing 1. A strainer 14 is attached to the push rod 10 so as to contact the upper surface of the strainer stopper 13. The strainer 14 has a cylindrical shape and a cage shape in which a mesh is also provided on a canopy portion. The push rod 10 is provided with a stopper 16.

The rest of the configuration is the same as that of the conventional example, and the same portions are denoted by the same reference numerals and description thereof will be omitted.

When the push rod 10 is pushed up to drain the water in the check valve for a cold region having the above-described structure, the valve body 6 is pushed up by the push rod 10 to drain the water. At this time, the strainer 14 is also moved upward together with the push rod 10. In addition,
Since the stopper 16 is provided, the strainer 14 does not come into contact with the valve seat portion 5. That is, even when the stopper 16 contacts the valve casing 1, the strainer 14 is separated from the valve seat 5.

When the strainer 14 moves upward, the strainer 14 separates from the strainer stopper 13, and a gap is formed between the two. Therefore, all the water above (downstream of) the strainer 14 flows down through this gap. As a result, there is no or almost no residual water in the cold district check valve. Even if a small amount of water freezes, when the water supply pressure is applied, the water flows in the forward flow direction, and the small amount of ice melts quickly.

In the above embodiment, a basket-shaped strainer is used, but strainers of various shapes such as a board-shaped strainer can be used.

In the present invention, the push rod may be of a manual type, or may be driven by a solenoid or the like.

[0021]

As described above, the check valve for a cold region of the present invention prevents freezing of residual water despite the provision of the strainer.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a check valve for a cold district according to an embodiment.

FIG. 2 is a cross-sectional view of a check valve for a cold district according to a conventional example.

[Description of Signs] 1 Valve casing 6 Valve body 9 Drainage port 10 Push rod 13 Strainer stopper 14 Strainer

Claims (1)

(57) [Scope of request for utility model registration] 1. A cylindrical valve casing having an inflow port at a lower portion and an outflow port at an upper portion, and a valve provided with a seat surface facing upward at an intermediate portion in a vertical direction in the valve casing. A seat portion, a valve body provided to be vertically movable so as to be seated on the valve seat portion from above, a spring for urging the valve body in a seating direction, and an upper end directly below the valve body. A check rod for a cold district having a push rod whose lower end is extended through a drain port at the bottom of the valve casing to the outside, wherein a strainer is attached to the push rod below the valve seat portion. A non-return check for a cold region, wherein the strainer comes into contact with the push rod when the push rod is moved downward, and a strainer stopper is provided for partitioning a primary side and a secondary side of the strainer. valve.