JP7717554B2 - Check valve device with foreign object intrusion prevention function - Google Patents

Description

The present invention relates to a check valve device that prevents foreign matter from entering a check valve and prevents backflow due to foreign matter getting caught in the valve seat surface.

If a check valve leaks, fluid will flow back to the primary side of the check valve, where it should not, which can cause malfunctions in processes and various equipment.
The most common cause of check leaks is foreign matter getting caught in the valve seat surface. It is known that rust that has developed inside the piping over time or foreign matter that has entered from outside the system adheres to the valve seat surface of the check valve, causing poor closing performance and resulting in check leaks.

A strainer is sometimes installed on the upstream side of a check valve to prevent foreign matter from entering the valve, but strainers require regular maintenance. If maintenance is neglected, the strainer can become clogged, leading to increased pressure loss in the piping and preventing the planned flow rate, which can have a negative impact on the process.
In horizontal piping, foreign matter such as dirt tends to accumulate at the bottom of the piping due to gravity, and this dirt can travel down the bottom of the piping and be carried into the check valve.

Furthermore, the following Patent Document 1 discloses a check valve device installed in a weephole of an underground structure having a waterway, which includes a valve body installed in the weephole and having a flow path, a main valve seat formed in the valve body facing the waterway, and a main valve body that moves toward and away from the main valve seat, forming a main check valve that allows flow toward the waterway and prohibits flow in the reverse direction, and protective means that is located closer to the opening of the weephole than the operating area of the main valve body and that allows flow toward the waterway while preventing foreign matter from entering the operating area of the main valve body from the waterway.

JP 2019-11810 A

In horizontal piping, foreign matter tends to flow along the bottom of the pipe, and in steam piping in particular, steam drain flow occurs at the bottom of the pipe, forming a two-layer flow. Compared to the steam flow inside the pipe, steam drain is more likely to collect foreign matter such as dirt, and it is expected that foreign matter will be brought into the check valve via the steam drain flow.

To solve the above problems, the present invention provides a check valve device that prevents steam drain flowing down the bottom of the piping from entering the check valve by providing a mesh, plate-shaped, or net-shaped weir only at the bottom of the check valve. This also stops foreign matter, such as dust, contained in the steam drain at the weir, preventing the intrusion of foreign matter into the check valve and preventing check leakage due to foreign matter getting caught in the valve seat surface.

The check valve device with foreign matter intrusion prevention function of the present invention is a check valve device installed in a pipe with a flow path, and is characterized by having a valve body with a flow path installed between an inlet pipe and an outlet pipe, a valve seat formed on the valve body facing the flow path, a valve element that moves toward and away from the valve seat, and a check valve that allows flow toward the flow path and prohibits flow in the reverse direction, with a weir structure provided on the bottom surface of the inlet/outlet joint of the valve body.

In the device of the present invention, the weir structure can be a plate-like structure, a mesh-like structure, a net-like structure, or the like. In short, any structure is acceptable as long as it prevents the intrusion of foreign matter flowing at the bottom of the pipe while minimizing the obstruction of fluid flow to the valve body.

When the check valve device of the present invention is used on steam piping, steam condensate containing foreign matter that is prevented from entering the check valve by the weir structure can be discharged together with the steam condensate from steam traps installed before and after the check valve.

This invention prevents steam drain flowing down the bottom of the piping from entering the check valve by providing a mesh or plate-shaped weir only at the bottom of the check valve. Foreign matter such as dust contained in the steam drain is also stopped at the weir, preventing it from entering the check valve and preventing check leakage due to foreign matter getting caught in the valve seat surface. Furthermore, by providing a weir only at a portion of the bottom of the check valve, there are no obstacles in the majority of the piping flow path that would increase pressure loss. Therefore, unlike strainers, there is no increase in piping pressure loss even without regular maintenance, and operation can be achieved over long periods without maintenance.

When a check valve device is used on steam piping, steam condensate containing foreign matter that is prevented from entering the check valve by the weir structure (weir structure part) is discharged together with the steam condensate from steam traps installed before and after the check valve, eliminating the need to disassemble and clean the weir structure (weir structure part), achieving a maintenance-free system.

FIG. 1 is a side view illustrating an example of the general configuration of a check valve device having a foreign matter intrusion prevention function according to the present invention. FIG. 2 is a front view illustrating an example of the general configuration of a check valve device having a foreign matter intrusion prevention function according to the present invention. FIG. 3 is an explanatory diagram showing an example of the schematic configuration of a check valve device having a foreign matter intrusion prevention function according to the present invention when used in a steam pipe.

The following describes an embodiment of the present invention based on the drawings, but the present invention is not limited to the embodiment described below and can be modified as appropriate.

In this embodiment, a weir structure is provided on the bottom surface of the inlet/outlet joint of the check valve body to prevent foreign matter such as dirt that has accumulated at the bottom of the piping from being brought into the valve body.
The weir structure may be in the form of a plate, mesh, net, etc., and any structure may be used as long as it prevents the intrusion of foreign matter flowing to the bottom of the pipe while minimizing the obstruction of fluid flow to the valve body.

1 and 2 show an example of the schematic configuration of a check valve device of the present invention. In the check valve device 1, a valve body 4 is installed between an inlet pipe 2 and an outlet pipe 3. Although not shown in detail, the check valve device 1 is equipped with a valve seat formed on the valve body 4 and facing the flow path, a valve body that moves toward and away from the valve seat, and a check valve that allows flow toward the flow path and prohibits flow in the reverse direction.
A weir structure 5 is provided on the bottom surface of the inlet/outlet joint of the valve body 4.

By providing the weir structure 5 only at the bottom of the check valve, steam condensate flowing down the bottom of the pipe is prevented from entering the check valve, and foreign matter such as dirt contained in the steam condensate is stopped at the weir section, preventing it from entering the check valve and preventing check leakage due to foreign matter getting caught in the valve seat surface. Furthermore, by providing the weir structure 5 only at a portion of the bottom of the check valve, there are no obstacles in the majority of the piping flow path that would increase pressure loss. Therefore, there is no increase in piping pressure loss like with strainers, even without regular maintenance, and operation can be achieved over long periods without maintenance.

FIG. 3 shows an example of a configuration in which, when a check valve device is used in a steam pipe, steam traps are installed before and after the check valve to achieve an automatic cleaning effect (maintenance-free) by steam drain.
Steam drain containing foreign matter prevented from entering the check valve device 1 by the weir structure 5 is discharged together with the steam drain from steam traps 6 and 7 installed before and after the check valve, eliminating the need to disassemble and clean the weir structure 5 (weir structure). The steam trap 6 is specifically provided in a steam drain discharge pipe 8 branching off from the inlet pipe 2. Similarly, the steam trap 7 is specifically provided in a steam drain discharge pipe 9 branching off from the outlet pipe 3.

1 Check valve device 2 Inlet piping 3 Outlet piping 4 Valve body 5 Weir structure 6, 7 Steam trap 8, 9 Steam drain discharge piping

Claims (3)

A check valve device with a foreign matter intrusion prevention function is a check valve device that is installed in a pipe having a flow path, and that comprises: a valve body that is installed between an inlet pipe and an outlet pipe and has a flow path; a valve seat formed on the valve body and facing the flow path; a valve element that moves toward and away from the valve seat; and a check valve that allows flow toward the flow path and prohibits flow in the reverse direction, and is characterized in that a weir structure is provided on the bottom surface of the inlet and outlet joint of the valve body to prevent the intrusion of foreign matter contained in steam drain . The check valve device with a foreign object intrusion prevention function described in claim 1, wherein the weir structure is one of a plate-like structure, a mesh-like structure, and a net-like structure. A check valve device with a foreign matter intrusion prevention function as described in claim 1 or 2, in which, when the check valve device is used in steam piping, steam condensate containing foreign matter prevented from entering the check valve by a weir structure is discharged together with the steam condensate from steam traps installed before and after the check valve.