JPS6052358B2 - Valve seat structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a valve seat structure in which a downward-opening bucket float disposed freely in a valve chamber directly contacts the valve seat and is moved to and from the seat while swinging.

FIG. 1 shows a free bucket float type steam trap equipped with the above valve seat structure. The trap housing is formed of a main body 1 and an upper lid 2 fixed to the main body 1 via a gasket. A valve chamber 3 is formed in the housing, and an inlet 4 communicates with the valve chamber 3 through an inlet passage 5, an introduction hole 7 of an introduction pipe 6, and a through hole 8, and an outlet 9 communicates with the valve chamber 3 through a valve hole 11 and an outlet passage 10. communicate. The valve hole 11 is provided with a gasket 1 on the ceiling wall of the valve chamber 3.
The valve seat member 13 is screwed through the valve hole 1 through the valve hole 1.
A cylindrical diaphragm member 14 is fitted on the outlet side of the tube 1 to provide a diaphragm portion. A downward-opening Burkett float 16 is disposed in the valve chamber 3 in a free state. The float 16 has a valve surface 17 on its outer periphery.
It is formed from a spherical shell 18 provided with a spherical shell 18 and an annular weight 19 fixed to the lower opening edge of the spherical shell 18. Further, a small hole 20 for venting air is provided in the upper part. In the above trap, when steam is introduced into the float 16 through the introduction pipe 6,
As shown in the figure, it floats up, seats on the valve seat member 13, and closes the valve hole 12. Further, when condensate is introduced into the float 16, the float 16 sinks and leaves the valve seat member 13 to open the valve hole 11. During the above-mentioned opening/closing operation, the float 16 comes into contact with one point B of the valve seat member 13 in the state shown by the two-dot chain line A, and this point B
swings around the fulcrum. The area near point B where the float 16 comes into contact has an extremely small area because the tip of the valve seat member 13 is tapered to a point to increase contact surface pressure and improve sealing performance. However, rolling and sliding of the float 16 occurs near this point B, and the float 16 formed over a wide area
Compared to the valve surface 17, the wear near this point B was extremely significant, and the seal surface eventually broke, causing fluid leakage. In view of the above-mentioned circumstances, the present invention has been developed so that the valve seat portion that abuts a valve body such as a float is rotatable, so that the abutting portion of the float is fixed and wear does not progress locally, and it is durable. The purpose of the present invention is to provide a valve seat structure that is flexible and resistant to fluid leakage.

Next, the present invention will be explained based on the embodiments shown in FIGS. 2-4.

However, the example is applied to the above-mentioned free bucket float type steam trap. In FIG. 2, the valve seat member 31 is formed by being divided into a main body portion 32 and an abutment portion 33.

The main body portion 32 has an inner peripheral portion 35 on the primary side of the valve hole 34 and a threaded portion (not shown) that is screwed onto the ceiling wall of the valve chamber. This main body portion 32 is made of corrosion-resistant metal material such as stainless steel. The contact portion 33 is rotatably fitted to the outside of the inner peripheral portion 35. During this fitting, the contact portion 33 and the main body portion 32
Glue the space between them with silver solder. 36 indicates a layer of silver solder.
The contact portion 33 is made of a wear-resistant metal material such as cemented carbide. The tip end 37 of the inner circumferential portion 35 is caulked outwardly to sandwich the abutting portion 33. After this caulking work, the valve seat member 31 is heated, the silver solder layer 36 is removed, and the contact portion 33 is heated.
to be able to rotate. According to this embodiment, the contact portion 3
3 can rotate independently, and the valve body such as a float is located at a certain point (
There is no possibility of local wear of the valve seat due to contact with the valve seat (near point B in FIG. 1).

Therefore, it is durable and fluid leakage is less likely to occur. The contact portion 33 rotates due to the force of the float when it comes into contact with the float, the action of fluid pressure, and the like. Since the contact portion 33 is made of a wear-resistant metal material, wear caused by the contact of the float is further reduced. The inner circumferential portion 35, which the float comes into contact with when the valve is closed, and which is prone to erosion, is made of an erosion-resistant metal material, so erosion is difficult to occur. The contact portion 33 is attached to the main body portion 32 by caulking, and the attachment is simple and easy to manufacture. If the silver solder layer 36 disappears naturally by electrochemical corrosion, the operation of heating to remove the silver solder can be omitted. If the hem 38 of the inner circumferential portion 35 is formed into an arc shape as shown, stress concentration in this portion will be reduced and the strength will be improved. Furthermore, if the abutting portion 33 is chamfered 39 as shown in the figure, this portion will not be damaged. The embodiment shown in FIG. 3 will be explained.

The valve seat member 41 is formed from a main body portion 42 and a contact portion 43,
It is made of the same metal material as the one in Figure 2. The main body portion 42 has a cylindrical inner peripheral portion 44 projecting into the valve chamber and an annular recess 45 . 46 indicates a valve hole.

The contact portion 43 is rotatably fitted into the recess 45 . A shoulder portion 47 is provided on the outer periphery of the recessed portion 45, and a stopper ring 48 is fitted into this shoulder portion 47. The contact portion 43 is provided with a flange 49 so as to be engaged between the bottom wall of the recess 45 and the stopper ring 48. In this embodiment, a stopper ring 48 is fitted onto the main body part 42, so that the contact part 43 can be rotated.

By simply fitting the stopper ring 48, there is no need to caulk the inner peripheral portion 44 or remove silver solder.
The embodiment shown in FIG. 4 will be explained.

However, in this embodiment, a contact portion 43'' having a shape similar to that shown in FIG. 3 is rotatably attached to the main body portion 42'' with a bag-shaped nut 51. Other parts are the same as those in the embodiment shown in FIG. 3, so the same numbers as those in the embodiment shown in FIG. 3 are given so that the description can be referred to. In this embodiment, the bag-shaped nut 51
The contact portion 43'' can be replaced by attaching and detaching the valve seat portion (
(contact part) can rotate, and the contact area of the valve body is limited.
This prevents wear from progressing locally and causing fluid leakage, and provides a durable valve seat structure.

The present invention is applicable to all types of traps in which the valve body contacts and swings, and is also applicable to free-float type steam traps in which a sealed float is disposed freely within the valve chamber.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a free bucket float type steam trap having a conventional valve seat structure, and FIGS. 2 to 4 are partially enlarged sectional views of a valve seat structure according to an embodiment of the present invention. 31, 41...Valve seat member, 32, 42, 42''
...Body part, 33, 43, 43'' ...Contact part, 3
4, 46... Valve hole, 35, 44... Inner peripheral portion, 36... Silver solder layer, 37...
Caulking part, 45... Annular recessed part, 47...
Shoulder part, 48... Stopper ring, 49...
・Tsuba, 51... Bag-shaped nut.

Claims (1)

[Claims] 1 A downward-opening bucket float placed freely in the valve chamber is in direct contact with the valve, and the cylindrical protrusion forming the inner periphery of the primary side of the valve hole is It has a valve seat main body provided with a valve seat, and a substantially cylindrical valve seat abutting part that a valve body such as a bucket float comes into contact with, and the valve seat abutting part is located on the outside of the cylindrical protrusion of the valve seat main body. A valve seat structure characterized in that the valve seat is rotatably arranged and locked with an appropriate play in the axial direction.