JPS6213559B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disk-type steam trap that automatically discharges condensate generated in steam-using equipment or the like.

For high temperature and high pressure disc type steam traps,
Leakage occurs while the valve disc is in the seated position,
As a result, there is a problem in that circular radial erosion marks are formed on the inner seat surface and the contact surface of the inner seat of the disk.

This is believed to be due to a thin layer of water interposed between the valve seat and the valve disk. This will be explained with reference to FIG. 3, which is a partially enlarged view of the disc steam trap in the closed state. The lower surface of the valve disk 1 is precisely finished flat, and the inner and outer seats 2, 3 are also precisely finished flat. In this way, when the valve disc 1 is seated on the inner and outer seats 2 and 3, a thin layer of water is formed between the contact surfaces (however, this is exaggerated in the figure), and the valve disc 1 is Seats 2 and 3
It is thought that it is raised by about 0.001 to 0.01 mm. Considering the pressure relationship between the variable pressure chamber 4 surrounding the valve disk 1, the annular groove 6 communicating with the discharge hole 5, and the ejection hole 7, the pressure of the ejection hole 7 sandwiching the inner seat 2 and the pressure of the annular groove 6 are determined. The pressure difference between the valve disc 1 and the pressure difference between the annular grooves 6 that sandwich the external valve seat 3 is much larger than that of the annular groove 6, and for this reason, the water layer 8 between the valve disc 1 and the external valve seat 3 maintains the valve disc 1. Also, it is thought that the layer of water between the valve disc 1 and the inlet seat 2 is pushed out, and leakage occurs even though the valve disc 1 is in the closed state.

The present invention aims to solve the above-mentioned problems, and the technical means taken for this purpose is to install a disc-shaped valve disk that sits on and off from a valve seat surface consisting of an inner ring valve seat and an outer ring valve seat, behind the disk-shaped valve disk. In a valve that automatically opens and closes by controlling pressure changes in a variable pressure chamber, a thin annular groove is formed on the inner valve seat surface, and no through hole is formed in the valve disk. ,
It is something.

The operation of the above technical means is as follows.
Condensate collects in the annular groove formed on the inner valve seat surface each time the valve is opened or closed. In addition, the steam pushed out from the ejection hole to the discharge hole is also condensed in this narrow groove. Therefore, a thin layer of water is maintained not only between the valve disc and the outer ring valve seat, but also between the inner ring valve seat and no leakage occurs.

The illustrated embodiment will be described below.

In FIG. 1, 10 is a main body, 11 and 12 are an inlet passage and an outlet passage formed in the main body 1, respectively.
13 is the bolt/nut 1 via the gasket 14
The lid 5 is fixed to the main body 1, and the inner lid 17 is a valve seat member 16. The inner lid 17 is attached to the main body 1 by screwing with bolts 18. 19 is a gasket interposed between the valve seat member 16 and the inner lid 17; 20 is a gasket interposed between the valve seat member 16 and the main body 1;
This is a gasket interposed between the inner wall of the 21 is an outer chamber communicating with the inlet passage 11; 22 is a valve seat member 1;
6 and a gasket 20. Reference numerals 23 and 24 are an inner seat and an outer seat, and the seat surfaces are polished to a highly accurate flat surface. A valve disk 25 is seated on the inner and outer transfer seats 23 and 24, the lower surface of which is polished to a high precision like the seat surfaces of the inner and outer transfer seats 23 and 24, and is placed freely in the variable pressure chamber 26. 27 is the entrance passage 11
a spout hole 2 that communicates with the interior and opens at the center of the inner port 23;
8 is an annular groove 2 formed between the inner and outer seats 23 and 24.
9 is a discharge hole communicating with the outlet passage 12. 3
0 is a bimetal ring 11 that slides up and down on an inclined surface 32, and 31 is a retaining ring.

FIG. 2 is a partially enlarged view of FIG. 1 showing a state in which the valve disk 25 is seated on the inner and outer seats 23 and 24. And, as you can see from Figures 1 and 2,
An annular narrow groove 33 is provided in the center of the inner seat 23 surface.

With the above configuration, when the valve disk 25 is seated on the external and external transfer seats 23 and 24, a thin layer of water is formed not only between the disk 25 and the external transfer seat 24, but also between the valve disk 25 and the internal transfer seat. It is also formed and maintained between the seats 23. That is, condensate accumulates in the annular pore 33 every time the opening/closing operation is performed, and the steam pushed out from the jet hole 27 toward the discharge hole 28 is also condensed in the annular pore 33 , and thus the annular pore 33 of the inner transfer seat 23 is A water seal is formed between the outer annular valve seat portion and the valve disk 25 as shown at A. Therefore, there is almost no steam leakage when the person is seated.

Furthermore, the annular pore 33 also functions as a labeling groove, increasing passage resistance and preventing steam leakage.

Furthermore, the annular pore 33 acts to suppress the fluid passage speed even when the valve disc 25 is unseated and the valve is opened, and has the same effect as the resistance groove bored in the conventional valve disc. , the resistance groove of the valve disc can be made shallower or omitted, and the strength of the valve disc can also be improved.

As described above, according to the present invention, leakage can be prevented when the valve disk is seated by a simple means of forming annular pores in the inner seat surface, and the valve disk and valve seat can be prevented from leaking. It can also prevent erosion.

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional view of the disc-type steam trap of the embodiment, Figure 2 is a partially enlarged view of Figure 1, and Figure 3 is a partial enlarged view of Figure 1.
The figure shows a partially enlarged view of a conventional disc-type steam trap. 10 is a main body, 11 is an inlet passage, 12 is an outlet passage, 13 is a lid body, 16 is a valve seat member, 17 is an inner lid,
23 is an inner seat, 24 is an outer seat, 25 is a valve disk, 26 is a variable pressure chamber, 27 is a jet hole, 28 is a discharge hole, 29 is an annular groove, and 33 is a narrow groove.

Claims (1)

[Claims] 1. A disk-shaped valve disk that sits on and off from the valve seat surface consisting of an inner ring valve seat and an outer ring valve seat, and opens and closes the valve by automatically controlling it by pressure changes in a variable pressure chamber formed behind it. A disc-type steam trap in which a thin annular groove is formed on the inner valve seat surface and no through hole is formed in the valve disk.