JPH017893Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a metal seal gate valve used in various plants such as boiler plants, and more specifically, a copper gasket that is attached to a valve plate and can be moved into and out of contact with the valve seat. Concerning technology to keep the temperature constant.

Prior Art There is a conventional metal seal gate valve as shown in Fig. 1, for example, where 1 is a valve plate, 2 is a gasket holder, 3 is a copper gasket, 4 is a valve box, 5 is an air cylinder, and 6 is an open/close valve. 7 is a sealing bellows, 8 is a seal load adjusting bellows, 9 is a valve seat, 10 is a stopper, 11 is a fluid inlet, 12 is a fluid outlet, and 13 is a fluid passage hole.

The valve plate 1 and the valve seat 9 are respectively disposed in the valve body 4, and the valve plate 1 closes the fluid passage hole 13 of the valve seat 9, thereby allowing fluid to flow from the fluid inlet 11 of the valve body 4 to the fluid outlet 12. Passage is blocked. This fluid passage is opened when the valve plate 1 separates from the valve seat 9 and opens the fluid passage hole 13, and the fluid flows from the inlet 11 of the valve box 4 toward the outlet 12.

The valve plate 1 is moved via an opening/closing piston 6 that reciprocates by the operation of an air cylinder 5 attached to the outside of the valve body 4. Further, a stopper 10 is provided on the inner wall of the valve box 4, and this stopper 10 stops the movement of the valve plate 1, so that the valve plate 1 is positioned at a position where the fluid passage hole 13 of the valve seat 9 is accurately closed.
Further, a sealing bellows 7 disposed inside the air cylinder 5 allows the working air of the air cylinder 5 to be connected to the valve box 4.
Prevents it from flowing inward.

Therefore, there is a gasket holder 2 at the bottom of the valve body 1.
A gasket 3 made of copper is attached through the valve, and when the valve is closed, this copper gasket 3 touches the valve seat 9.
to reliably seal the gap between the valve body 1 and the valve seat 9. A bellows 8 for adjusting the sealing load is interposed between the valve seat 9 and the valve box 4, and by changing the pressure of the fluid such as air or nitrogen gas injected into the bellows 8, the sealing can be performed. The load can be adjusted.

Problems to be Solved by the Invention The sealing load is adjusted according to the operating temperature of the copper gasket 3.

That is, since copper has conventionally been generally used as a material for metal gaskets, it has been necessary to change the sealing load depending on the operating temperature of the copper gasket 3.

In other words, the copper used as the material for metal gaskets is the various pure copper plates (50% rolled 1
There is a temperature dependence of mechanical properties as shown in the diagram showing the influence of annealing temperature on mechanical properties of mm). Therefore, it is necessary to reduce the sealing load as the temperature rises. For example, if the same sealing load as at room temperature is applied at a temperature of around 300°C, the sealing part of the copper gasket 3 will collapse.
The sealing properties will be lost.

As described above, when using conventional gate valves at high temperatures, there was a risk that the life of the copper gasket would be extremely shortened unless the sealing load was adjusted with consideration to the operating temperature.

Means for Solving the Problems In order to solve the problems of the prior art, the present invention attaches a copper gasket that can freely move toward and away from the valve seat provided in the valve box to a reciprocating valve plate. In a metal seal gate valve with a bellows interposed between the seat and the valve body for adjusting the seal load, the valve seat and the valve body are each equipped with a heater, and the valve seat is also equipped with a thermocouple, or a metal seal gate valve made of copper is provided. A heater and a thermocouple are provided in the gasket, and a temperature controller is provided for adjusting the amount of heat generated by the heater by taking feedback from the thermocouple provided in the valve seat or the copper gasket.

Effect: According to such a means, the temperature of the copper gasket can be kept constant by adjusting the amount of heat generated by the heater using the temperature controller.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 3 and 4. In these figures, the same parts as shown in FIG. 1 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

FIG. 3 shows a first embodiment of the invention.

According to this embodiment, heaters a and b are embedded in the valve body 4 and the valve seat 9, which are the upper and lower parts of the valve plate 1 and therefore the copper gasket 3 when the gate valve is closed. , a thermocouple c for temperature measurement is attached to the valve seat 9.

Then, a temperature controller (not shown) takes feedback using a thermocouple c, adjusts the heating power of the heaters a and b, and keeps the temperature of the copper gasket 3 constant. According to the results of experiments, the optimum temperature setting for the copper gasket 3 was 150°C.

FIG. 4 shows a second embodiment of the invention.

In this embodiment, the number of heaters is reduced to one, and the heater d is directly attached to the copper gasket 3, and a thermocouple e for temperature measurement is also attached to the copper gasket 3.

Then, a temperature controller (not shown) takes feedback using a thermocouple e and adjusts the amount of heat generated by the heater d to keep the temperature of the copper gasket 3 constant.

Effects of the invention As described above, according to the invention, the temperature of the copper gasket in the metal seal gate valve can be kept constant, so the sealing load can be kept constant regardless of the operating temperature, and the sealing force in ultra-high vacuum can be maintained constant. Therefore, the life of the copper gasket can be extended, and there is no need to specially adjust the sealing load by the bellows interposed between the valve seat and the valve body.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the structure of a conventional metal seal gate valve, Figure 2 is a diagram showing the influence of annealing temperature on the mechanical properties of various pure copper plates, and Figure 3 is a metal seal according to the present invention. FIG. 4 is a sectional view showing another embodiment of the metal seal gate valve according to the present invention. 1... Valve plate, 2... Gasket holder, 3... Copper gasket, 4... Valve box, 5... Air cylinder, 6... Opening/closing piston, 7... Sealing bellows, 8... Seal load adjustment. bellows, 9...valve seat, 10...stopper, 11...fluid inlet, 12
...Fluid outlet, 13...Fluid passage hole, a, b...
Heater, c...Thermocouple, d...Heater, e...Thermocouple.

Claims (1)

[Scope of utility model registration request] A metal seal gate consisting of a copper gasket that can be freely moved toward and away from the valve seat provided in the valve box, attached to a reciprocating valve plate, and a bellows for adjusting the sealing load interposed between the valve seat and the valve box. In a valve, a heater is provided in each of the valve seat and the valve body, and a thermocouple is also provided in the valve seat, or a heater and a thermocouple are provided in a copper gasket, and feedback is provided by the thermocouple provided in the valve seat or the copper gasket. A metal seal gate valve characterized in that it is equipped with a temperature controller that adjusts the amount of heat generated by the heater.