JPH05248549A - Check valve - Google Patents

Abstract

PURPOSE:To prevent the occurrence of an abnormal sound at the time of valve closing operation, and a stress corrosion cracking by fitting a rubber sheet to the surface of a metal valve disc where in contact with a valve seat in such a way as freely detachable, regarding a check valve used in a high temperature gas exhaust system. CONSTITUTION:The bonnet 1 of a check valve has an exhaust gas inlet 2 and an exhaust gas outlet 3, and a valve seat 8 made of SUS 304 stainless steel or the like is provided at the inner edge section of the inlet 2. The base section of an arm 4 is pivotally supported on a bracket 5 in the bonnet 1, and a valve disc 7 made of SUS 304 stainless steel or the like is supported on the end of the arm 4. Also, the maximum opening of the disc 7 is restricted by a stopper 4a. In this check valve, a rubber sheet 9 is fitted to the surface of the disc 7 where in contact with the seat 8, in such a way as freely detachable via a check bolt and a retaining washer. In this case, fluoro-rubber having a rubber hardness value between 40 and 60 is preferably used for the rubber sheet 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a check valve used in a hot gas discharge system or the like.

[0002]

2. Description of the Related Art For example, in a radioactive waste treatment plant as shown in FIG. 3, a pipe 24 for sending hot exhaust gas from an exhaust gas filter 21 to a chimney 23 by a blower 22 is branched at a discharge side of the blower 22. Another pipe 26 connected to the incinerator cooling box 25 or the like may be connected via a check valve 30.

When such a discharge system is in steady operation, the inside of the pipe 24 is maintained at a high pressure by the discharge pressure of the blower 22, but when the blower 22 is started, the pressure in the pipe 24 is The pulsation may cause the check valve 30 to operate.
By the way, generally, the check valve 30 used in such a place is
In order to secure reliability, it is common knowledge that both the valve disc and the valve seat are made of metal such as SUS 304 and the contact surfaces of both are metal-touch. Check valve for this
When the thirty actuated, the metals could hit violently together, producing a loud noise, like a church bell.

[0004]

The present invention has been completed to solve the above-mentioned conventional problems and provide a check valve capable of preventing noise during operation while maintaining high reliability. It is a thing.

[0005]

The present invention, which has been made to solve the above-mentioned problems, is characterized in that a rubber sheet is detachably attached to a contact surface of a metal valve disc with a valve seat. The check valve is the main point.

[0006]

The present invention will be described in more detail with reference to the embodiments shown in the drawings. In FIG. 1, 1 is a check valve bonnet, 2 and 3 are exhaust gas inlet / outlet ports, 4 is an arm swingably supported by a pin 6 at the tip of a bracket 5, and 7 is supported by the tip of this arm 4. It is a valve disc made of SUS 304. This valve disk 7 contacts the SUS 304 valve seat 8 formed outside the exhaust gas inlet / outlet 2, and closes the valve while the internal pressure of the check valve bonnet 1 is higher than the pressure outside the inlet / outlet 2. Is what you do. Reference numeral 4a is a stopper attached to the arm 4 in order to regulate the maximum opening amount of the valve disc 7.

FIG. 2 is an enlarged view of the valve disc 7 according to the present invention, showing a state in which a rubber sheet 9 is detachably attached to a contact surface in contact with the valve seat 8 by a retaining bolt 10 and a pressing washer 11. Shows. In this embodiment, fluororubber having a rubber hardness of 40 to 60 is used as the rubber sheet 9. The reason is as follows.

Properties required of the rubber sheet 9 include corrosion resistance, heat resistance, impact resistance, abrasion resistance, sound deadening property, and sealing property. Therefore, when these characteristics are evaluated for various rubber sheets, the results are shown in Table 1. As a result, it is understood that it is preferable to use fluororubber. Further, when the rubber hardness is less than 40, plastic deformation occurs during use to impair the sealing property, and when it exceeds 60, the sound deadening effect decreases, so the rubber hardness is 40 to 60.
Most preferred are fluororubbers.

[0009]

[Table 1]

[0010]

In the check valve of the present invention thus constructed, the check valve is actuated because the rubber sheet 9 made of fluororubber or the like is attached to the contact surface of the valve disc 7 with the valve seat 8. Even when doing so, it is possible to prevent the metal from coming into contact with each other and to prevent a loud noise from being generated.
Moreover, the rubber sheet 9 can prevent stress corrosion cracking due to direct contact between metals, and can be easily replaced when the rubber sheet 9 is worn due to long-term use. Therefore, the check valve of the present invention is
It is suitable for use in a high temperature gas discharge system as shown in FIG.

[0011]

As described above, the common sense that the check valve of the present invention should have a metal touch on the contact surface between the valve disc and the valve seat, and a rubber sheet is attached to the valve disc. This makes it possible to prevent noise during operation while maintaining high reliability. Therefore, the present invention contributes significantly to the industry as a check valve that solves the conventional problems.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a valve disc according to an embodiment of the present invention.

FIG. 3 is a piping system diagram showing an example of a usage state of the check valve of the present invention.

[Explanation of symbols]

 7 valve disc 8 valve seat 9 rubber sheet

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[Procedure amendment]

[Submission date] March 16, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art For example, in a radioactive waste treatment plant as shown in FIG. 3, a pipe 24 for sending hot exhaust gas from an exhaust gas filter 21 to a chimney 23 by a blower 22 is branched at a discharge side of the blower 22. Another pipe 26 connected from the miscellaneous solid incinerator safety valve 25 or the like may be connected via the check valve 30.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

When such an exhaust system is in steady operation, the inside of the pipe 24 is maintained at a positive pressure by the discharge pressure of the blower 22. However, when the blower 22 is started, the pressure in the pipe 24 is The pulsation may cause the check valve 30 to operate. By the way, generally, the check valve 30 used in such a place has a valve disk and a valve seat both made of SUS in order to ensure reliability.
It is common knowledge that the contact surfaces of both are made of metal such as 304 and have a metal touch. As a result, when the check valve 30 was activated, the metals could be hit violently and produce a loud noise such as a church bell bell.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010]

In the check valve of the present invention thus constructed, the check valve is actuated because the rubber sheet 9 made of fluororubber or the like is attached to the contact surface of the valve disc 7 with the valve seat 8. Even when doing so, it is possible to prevent the metal from coming into contact with each other and to prevent a loud noise from being generated.
Moreover it is also possible to prevent the stress corrosion cracking due to the metal each other is in direct contact with the rubber sheet 9, high
A good sealing property can be maintained. Further, when the rubber sheet 9 is worn due to long-term use, it can be easily replaced. Therefore, the check valve of the present invention is suitable for use in a high-temperature gas discharge system as shown in FIG.

Claims (1)

[Claims] 1. A check valve, wherein a rubber sheet is detachably attached to a contact surface of a metal valve disc with a valve seat.