JP7604259B2 - Packing integrated check valve and packing attachment member used therefor - Google Patents

Description

The present invention relates to a gasket-integrated check valve that is installed via an expandable pipe on the primary side of a water meter, and a gasket mounting member used therewith.

For the gasket-integrated check valve to be installed on the primary side of the water meter, Patent Document 1 proposes that a flange body attached to the rear end of the cartridge cage be sandwiched between the secondary end face of the fitting space provided at the secondary end of the telescopic pipe unit and the primary end face of the water meter, and the watertightness and tightness of the inner circumference of the telescopic pipe and the outer circumference of the cartridge cage are maintained by an O-ring.

In the description of Patent Document 2, a check valve is attached to the inside of a cylinder that is integral with the flange portion, and like Patent Document 1, the cylindrical inner circumference and an O-ring are responsible for preventing backflow.

Patent No. 6228429 Design Registration No. 1092792

However, the packing flange body in Patent Documents 1 and 2 is attached to the rear end of the cartridge cage to strengthen the support force against the flow pressure from the primary side to the secondary side, and the cartridge cage is fitted into a fitting space provided at the secondary end of the telescopic tube unit so that the flange body is snap-fitted to the rear end of the cartridge cage, which creates a problem in that when replacing the check valve, the telescopic tube also needs to be replaced with a telescopic tube that is suitable for the check valve.

There are problems with continued use of existing telescopic pipes, such as discoloration of the inner diameter due to long-term flow of tap water, the adhesion of foreign matter and the appearance of corroded areas such as verdigris due to the chlorine contained in tap water, and furthermore, problems with continued use include cases where the inner diameter of the telescopic pipe units is different, the casting surface is exposed because the inner diameter is formed from casting, and it is difficult to prevent backflow with O-rings, etc. However, there are still demands for continued use, such as the cost of replacing the telescopic pipe and water-stopping measures using O-rings, etc. on the inner surface of the telescopic pipe.

In addition, by directly supporting the cartridge cage with the flange body, the length of the sliding support section of the check valve shaft must be long, and furthermore, since the watertightness and tightness between the inner circumference of the telescopic tube and the outer circumference of the cartridge cage are maintained by an O-ring, there is a problem that the O-ring becomes stuck to the telescopic tube after long-term crimping use, such as when replacing the water meter, and becomes difficult to remove.

The present invention is a cylindrical cartridge body with a check valve seat formed in a tapered section at the tip and a flange body with a packing attached at the rear end, and a check valve mechanism with a check valve body abutted against the check valve packing by a spring biased in the pulling direction with a check valve shaft inserted through the center, inserted through a packing attachment member, and does not limit the combination of the telescopic pipe unit and the packing-integrated check valve. It does not use an O-ring to prevent backflow on the inner circumference of the telescopic pipe, and makes the cartridge body of the check valve cylindrical, and sets a packing attachment member that supports the check valve mechanism on the flange body that covers the peripheral end surface with a support column, thereby forming a packing-integrated check valve for use upstream of a water meter with a structure in which water is stopped by the check valve body, spring, check valve packing, cartridge body and check valve seat inside the packing-integrated check valve.

This makes it easy to replace or install the check valve with integrated packing even in cases where the inside diameter of the telescopic pipe is corroded, there are differences in the inside diameter dimensions due to differences in manufacturers, the valve is made with a cast surface, etc. Furthermore, by eliminating the O-ring shown by reference number 17 in the invention described in Patent Document 1, which maintains watertightness and tightness between the inner circumference of the telescopic pipe and the outer circumference of the cartridge cage, the problem of the O-ring becoming stuck to the telescopic pipe and becoming difficult to remove due to long-term crimping use when replacing a water meter, etc., is also solved.

Making the cartridge body cylindrical has the advantage that the length of the column supporting the sliding support part of the check valve shaft can be made shorter than when the flange body and cartridge cage are integrated as in the invention described in Patent Document 1, making it easier to manufacture the parts. However, making the cartridge body cylindrical restricts the volume of the water passage (cross-sectional area for water flow), and increases the pressure loss due to water flow become a problem.

In the present invention, therefore, a configuration was considered that suppresses the increase in pressure loss while making the cartridge body cylindrical. If the increase in pressure loss can be suppressed, it will be possible to use it in places with low water supply pressure and to make water supply facilities more compact. The Japan Water Works Association standard JWWA B 129 water supply backflow check valve specifies the maximum pressure loss when used in a water supply system. The present invention is configured to comply with the above standard by forming the tip of the packing mounting member that receives the check valve body into a tapered section to suppress the increase in pressure loss.

1 is a corresponding diagram showing a cross-sectional view of a check valve in a water-stopped state according to an embodiment of the gasket-integrated check valve of the present invention and a right side view thereof. FIG. FIG. 2 is a cross-sectional view of the check valve of FIG. 1 in a water-passing state. FIG. 2 is an exploded view showing the components of the packing-integrated check valve according to the present invention, showing a cross-sectional view of a packing mounting member and an external view of its outer surface. FIG. 2 is an exploded view showing the components of the integral packing check valve according to the present invention, in which a front view, a right-side cross-sectional view, and an external view and a rear view of the packing mounting member are correspondingly shown. FIG. 2 is an exploded view showing the components of the integral packing check valve according to the present invention, in which a front view, a vertical sectional view, and a rear view of the cartridge body are corresponding to each other. FIG. 2 is an exploded side view showing a state in which the packing-integrated check valve according to the present invention is inserted into a stop valve via an expandable pipe. FIG. 2 is an overall side view showing the gasket-integrated check valve according to the present invention with the essential parts cut away, omitting other piping to which a stop valve, an expansion pipe, and a water meter are sequentially connected. FIG. 2 is a cross-sectional view of a gasket-integrated check valve showing a basic structure capable of ensuring the maximum value of pressure loss based on the regulations of the Japan Water Works Association standard, and a corresponding right side view of the same structure. 9 is a design value table showing main design values for each nominal diameter of an embodiment of the packing-integrated check valve having the cross-sectional structure of FIG. 8 .

Figure 8 shows the cross-sectional structure of a check valve with integrated packing that exhibits regulated structural values that ensure that pressure loss is equal to or less than the maximum value based on the Japan Water Works Association standard JWWA B 129. A column 41 is formed on the packing mounting member 4, and there are two columns with a nominal diameter of 13 to 40. The tip that receives the check valve body 2 is formed into a tapered section 46 to prevent an increase in pressure loss.

As a result, it was confirmed that, for a nominal diameter of 20, the standard flow rate of the Japan Water Works Association standard JWWA B 129 is 38 [L/min] and the standard pressure loss value under the same standard is 20 [kPa] or less, but when the structure of Patent Document 1 is used, the standard value is 12 [kPa], and when the cylindrical cartridge body of this case is used, the standard value is 14 [kPa].

The embodiment of the present invention will be described in detail below with reference to the drawings. 1 is a cartridge body that constitutes the outer shell of the check valve cartridge. A check valve seat 5 that receives a check valve element 2 with a tapered tip is attached to the primary side. A packing attachment member 4 is attached to support the check valve element 2, which opens and closes by contacting the check valve seat 5 and the check valve packing 6, by biasing it to the primary side with a spring 3.

The tip of the outer diameter side of the check valve seat 5 is formed into a tapered surface, but by providing a two-sided width portion, it is possible to easily assemble the cartridge body 1 and the packing mounting member 4 by screwing them together.

A flange portion is formed at the secondary end of the packing-integrated check valve, which is composed of a flange body 13 and a flange body 44 formed at the secondary end of the packing attachment member 4. A packing 7 made of an elastic material such as rubber is attached to the flange body. The flange portion may be formed only by the packing attachment member 4 or the flange body of the cartridge body 1.

The packing attachment member 4 is attached to the cartridge body 1, and the primary end of the packing attachment member 4 has a sliding support 42 formed in the center, and a valve shaft insertion hole 43 passes through the center of the sliding support 42, through which the valve shaft 21 of the check valve body is inserted and guided. Thus, the check valve shaft 21 is inserted into the valve shaft insertion hole 43, and the check valve body 2 can be opened and closed by the spring 3.

The number of support columns 41 of the packing attachment member 4 is preferably as small as possible, since it restricts the cross-section of the water passage inside the check valve cartridge; for nominal diameters of 13 to 40, it is about two, and at most about four. A male thread 45 is provided on the secondary side of the packing attachment member 4, which threads into the female thread 12 provided on the secondary side of the cartridge body 1 to form a packing-integrated check valve.

By setting the gap between the outer diameter of the column 41 of the packing mounting member 4 and the inner diameter of the cartridge body 1 to 0.01 to 0.3 mm, the check valve body is positioned at the center of the water flow diameter, improving backflow prevention performance and preventing wear on the check valve body.

The gap between the check valve shaft insertion hole 43 of the packing mounting member 4 and the check valve shaft 21 of the check valve body 2 is set to 0.01 to 0.3 mm, which positions the check valve body at the center of the water flow diameter, improving backflow prevention performance and preventing wear on the check valve body.

In the present invention, the structure of the gasket-integrated check valve is such that a check valve seat 5 is set at the primary end of the cartridge body 1 as shown in Figure 8. If the inner diameter of the telescopic pipe and ΦB are the dimensional values shown in Figure 9, the diameter ΦA of the inlet part is 1.05 to 1.5 times ΦB, and the inner diameter part near where the check valve element is fully open is expanded by an angle of 15 to 90 degrees around the central axis of the cartridge body 1, so that ΦC is 1.3 to 1.8 times ΦB and ΦD is 0.7 to 0.95 times ΦC, eliminating the problem of pressure loss.

The gasket-integrated check valve configured as described above is used to close the existing stop valve P connected to the water meter M, remove the water meter M, and attach it to the existing expandable pipe S. After installation, the cap nut N attached to the expandable pipe S is joined to the water meter M, and the stop valve P is opened.

The gasket-integrated check valve and the gasket mounting member used therewith according to the present invention can be used very effectively in the water equipment industry because, as described above, it is easy to replace or install the gasket-integrated check valve even in new installations or in the middle of piping, in cases where the inside diameter of the telescopic pipe is corroded, there are differences in the inside diameter dimensions due to differences in manufacturers, or the valve is made with a cast surface.

1 Cartridge body 11 Flange body of cartridge body 12 Female thread that screws into male thread of packing mounting member 13 Female thread that screws into male thread of check valve seat 14 Inner diameter portion near where check valve body is fully open 2 Check valve body 21 Check valve shaft 22 Tapered portion at tip of check valve body 3 Spring 4 Packing mounting member 41 Support column body of packing mounting member 42 Sliding support body that guides check valve shaft 43 Check valve shaft insertion hole 44 Flange body of packing mounting member 45 Male thread that screws into female thread of cartridge body 46 Tapered portion of packing mounting member 5 Check valve seat 6 Check valve packing 7 Packing M Water meter N Cap nut P Stop valve S Expansion pipe

Claims (2)

A check valve with an integrated packing is formed by inserting a check valve mechanism into a cylindrical cartridge body having a check valve seat formed in a tapered section that narrows in diameter in the water flow direction at the tip side and a flange body section at the rear end where a packing is attached, the check valve mechanism having a check valve body abutted against the check valve packing by a spring that is biased in the tensile direction and a check valve shaft inserted through the center, via a packing mounting member formed in a tapered section at the tip that widens in diameter in the water flow direction . A packing mounting member comprising a sliding support section having an insertion hole in the center for slidingly supporting the check valve shaft, and a flange body having a packing attached to its peripheral end surface, supported by a support column having a tapered tip that expands in diameter in the direction of water flow .