JPH0237336Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is attached to fluid piping or a fluid container, and when the internal pressure rises above a predetermined value, the fluid corresponding to the excess pressure is blown out to prevent an abnormal increase in the pressure inside the piping or fluid container. This invention relates to an improvement in a so-called safety relief valve that can prevent the above-mentioned problems.

Conventionally, safety systems have been installed in, for example, hot water boilers, and when the water inside the boiler, which is kept in a sealed state, expands thermally and the pressure rises, the expanded hot water corresponding to the excess pressure is blown out to prevent abnormal pressure rises inside the boiler. Various types of relief valves are known. FIG. 1 shows an example of this. In the figure, 1 is a valve box having a valve seat portion 1a and a connection port 1b connected to a hot water boiler, etc., and 2 is a valve box that is connected to the valve box 1 in a liquid-tight or air-tight manner. A spring protection tube is connected to the spring protection tube and has an air outlet 2a and a top opening 2b; 3 is an adjustment ring screwed onto the outer periphery of the portion of the valve body 1 that protrudes into the spring protection tube 2; 4 is a valve for maintaining the center of the valve; It has a sliding part 4a that comes into sliding contact with the inner circumferential surface of the box 1, and when seated on the valve seat part 1a, an annular space a is formed outside the valve seat part 1a, and an adjustment ring 3.
5 is an adjustment spring, 6' is a valve stem, 7 is an adjustment screw screwed into the opening 2b, Reference numeral 8 denotes a cap screwed onto the top of the spring protection tube 2, and the pushing force against the valve body 4 caused by the pressure inside the boiler, that is, the pressure inside the connection port 1b, is used to push down the valve body 4 due to the elasticity of the adjustment spring 5. When the force exceeds the pressure, the valve element 4 is suddenly displaced upward due to the presence of the space a and the gap b, and the valve is opened, and expanded hot water equivalent to the overpressure is blown out from the outlet 2a. When the pressure inside the connection port 1b drops to a predetermined value, the valve body 4 is seated again on the valve seat 1a due to the elasticity of the adjustment spring 5, and the valve is closed. The safety relief valve works in this way, but if there is a sliding part in contact with the liquid as mentioned above, as time passes, scale may accumulate in the small gap in this part, or foreign matter may become trapped. Eventually, it may become impossible to slide.
If such a situation occurs, the pressure inside the boiler will inevitably rise abnormally, causing danger, and if the valve body 4 and valve seat 1a do not come into contact with each other and become unable to slide, air will flow from the air outlet 2a. This results in hot water constantly flowing out, resulting in energy loss. In addition, there is a gap b on the outlet side between the contact surface of the valve body and the valve seat, or a structure in which foreign matter or residual water after blowing tends to accumulate near the contact surface of the valve body and valve seat, as shown by symbol c. If this occurs, the same problems occur, such as the adhesion and accumulation of scale, the entrapment of foreign matter, and freezing, resulting in the same results as described above. Furthermore, since the contact between the valve body and the valve seat is made of metal, it is not only impossible to completely close the valve, but also the hot water comes into contact with the adjustment spring 5, valve stem 6', spring holder, adjustment screw 7, etc. when blown out, which is undesirable from a corrosion prevention standpoint. ,
In addition, the operation is easily affected by the adhesion of scale and foreign matter. In addition, especially for hot water boilers, for maintenance and inspection purposes, it is necessary to equip a test lever that can lift the valve body from the valve seat even when the boiler is unpressurized. The drawback of such a sealed structure is that it cannot be easily equipped with a test lever.

Figure 2 shows an example of a conventional safety relief valve that has no sliding parts in contact with the liquid, prevents hot water from coming into contact with the adjustment spring, lifting valve rod, spring holder, adjustment screw, etc. when blowing out, and is equipped with a test lever. It shows. In the figure, parts and portions that are substantially the same as those shown in FIG. 1 are given the same reference numerals. The diaphragm 10 is insulated by a diaphragm 10 which is held between the receiver 9 and the peripheral edge thereof is held between the valve box 1 and the spring protection cylinder 2. 11 is pin 12
The lever 11 is pivoted to the end of the lift valve rod 6 that protrudes above the cap 8.
The valve body 4 can be opened by rotating it to the left using the fulcrum a or by rotating it to the right using the corner 11b as the fulcrum. Note that the connection port and the air outlet are opposite to those shown in FIG. With this method, as mentioned above, the adjustment spring 5, lift valve rod 6, spring holder, adjustment screw 7, etc. do not come into contact with the fluid, so there is no problem of corrosion or adverse effects caused by scale, foreign matter, etc. Although there are advantages in that there are no sliding parts and the test lever can be installed relatively easily, since fluid pressure is constantly applied to the diaphragm 10,
The scope of use is limited to extremely low pressure applications, and it has a fatal defect as a safety relief valve in that if the diaphragm 10 is damaged, the valve body 4 will not open even if the fluid pressure exceeds the blowout pressure. To adjust the elasticity of the adjustment spring 5, remove the pin 12, remove the lever 11, take the cap 8, and tighten the lock nut (second
Since it was necessary to loosen the adjustment screw 7 (not shown in the figure, but present in the one shown in FIG. 3) and then turn the adjustment screw 7, the adjustment procedure was extremely troublesome.

FIG. 3 shows a conventional example of a safety relief valve which eliminates the disadvantages mentioned above while maintaining the advantages of the construction shown in FIG. Again, parts and portions that are substantially the same as those shown in FIG. 2 are provided with the same reference numerals. In the case of this method, the valve body 4 and the diaphragm 10 are connected by screwing a tightening screw 13 inserted through them into a tightening nut 15 fitted to the lift valve rod 6 via a spring washer 14. Therefore, if this tightening screw 13 loosens during use, the spring protection tube 2 will come out from this threaded part.
Fluid may enter the valve body, and as a result, the valve body 4 may become unable to open. In order to prevent this accident, a relatively large hole 2c is provided in the spring protection tube 2, but this is undesirable as it results in the drainage from the hole 2c contaminating the surrounding area. Further, on the outside of the valve seat portion 16a of the valve seat body 16 that comes into contact with the valve body 4, an annular space a and a gap b similar to the method shown in FIG. Although this can be done instantly, it is easy for scale and foreign matter to accumulate in this gap b, impairing its original function, and the center of the valve body 4 is thrown out of alignment when the valve is opened, so it cannot be done smoothly. The disadvantage is that it is difficult to perform effective actions. Also, in this conventional example, the procedure for adjusting the elasticity of the adjustment spring 5 was extremely troublesome, as in the case shown in FIG.

FIG. 4 shows yet another conventional example, and in this case as well, parts and portions that are substantially the same as those shown in FIG. 3 are given the same reference numerals. In the case of this method, the test lever 11 is brought into contact with its corner 11b against the top surface of the back pressure adjustment plate 8' which is directly screwed onto the adjustment screw 7, and is rotated clockwise about the corner 11b as a fulcrum. Since the valve 4 is configured to be able to open, if the adjustment screw 7 is moved up or down to adjust the adjustment spring 5, the amount of valve opening by the test lever 11 will change, and as a result, the blowout pressure will change. There was a problem that the adjustment range was significantly limited.

In view of the above problems, the present invention uses a non-rising adjustment screw (it does not move up or down even when the adjustment screw is turned), has a wide top surface, and has a test lever on the top surface of the adjustment screw. It is an object of the present invention to provide a safety relief valve in which the procedure for adjusting the adjustment spring is significantly simplified by bringing the valves into contact with each other, and the valve opening amount by the test lever does not change due to the adjustment. However, based on the embodiment illustrated below, parts and portions that are substantially the same as those shown in FIGS. As shown in the figure and FIGS. 10 to 14, the valve body 4 consists of a cup-shaped reinforcing metal fitting 4a made of austenitic stainless steel or the like and an elastic body part 4b made of synthetic rubber or the like filled and baked into the cup-shaped reinforcing fitting 4a. The upper part of the elastic body part 4b is connected to the diaphragm 10, the central projection part 4b' is tightly fitted concentrically to the diaphragm receiver 9, and the lower surface is formed so as to be able to abut against the valve seat surface. . In addition, a plurality of large and small through holes 4a' are bored in the bottom wall and peripheral wall of the reinforcing metal fitting 4a, as shown in FIGS. 11 and 12.
By filling or passing the elastic body part 4b into these through-holes 4a', the insufficient adhesion between the elastic body and the metal can be compensated for, and the outer periphery of the disc-shaped elastic body part can be prevented from peeling off from the metal fittings and curling up. are doing. The shape of the through hole 4a' is not limited to a circular shape. Furthermore, as is clear from FIG. 10, the end edge of the reinforcing metal fitting 4a is dimensioned so that it protrudes slightly downward from the valve seat contact surface over the entire circumference (indicated by d in FIG. 11).
is defined, and a so-called "cover" is provided, and preferably three protrusions 4a" extending further downward are formed on this protruding edge. By the way, the above-mentioned "cover" is the valve seat portion 1a. This serves to form a substantial annular space a on the outside of the valve seat, and the fluid that has passed through the valve seat contact surface accumulates in this annular space a, which greatly pushes up the valve body 4 and serves to increase the amount of air flow. ing. If this "covering" is too small, it will have little effect, and if it is too large, it will cause vibrations and other malfunctions, and the valve seat
A is too close to the stopper contact surface 1a' of a and there is a small gap b on the exit side (corresponds to b in Fig. 1).
This results in the formation of pores and causes malfunction, so it is necessary to select them appropriately. Further, the projection 4a'' serves to restrict the amount of compression of the soft elastic portion 4b of the valve body 4. That is, the projection 4a'' comes into contact with the stopper contact surface 1a' to maintain the lowered position of the valve body 4. Although it is limited to a certain position, generally the squeezing margin of this type of soft seat valve body increases over time, so if this protrusion 4a'' is not present, the blowout pressure will decrease rapidly and there will be frequent stoppage failures, which will eventually cause the valve to close. This will result in damage to the body 4.Also, without this type of stopper, it cannot be used for high pressure applications (those with large blowing pressure), but the protrusion 4a'' is formed over, for example, half the circumference or the entire circumference. When a small amount of hot water is frequently blown out, the same result as when there is a small gap on the outlet side as described above will occur, so it is important to form a minimum number of narrow protrusions. As mentioned above, austenitic stainless steel or the like is used as the reinforcing metal fitting 4a due to the need for strength and the need to minimize the adhesion of scale and foreign matter.According to the present invention, the valve including the reinforcing metal fitting 4a The entire outer surface of the body 4 is coated with a mold release agent such as fluororesin and baked. Therefore, adhesion (compatibility) of the valve body 4 to the valve body 1 (particularly the valve seat portion 1a and the diaphragm tightening portion), the spring protection tube 2, the diaphragm receiver 9, etc. is prevented, and the attachment (compatibility) with the valve seat contact portion is prevented. Between, the "covering" part of the reinforcing metal fitting 4a and the protrusion 4
It is possible to prevent scale and foreign matter from adhering between the valve body 4 and the outer peripheral surface of the valve seat portion 1a.
The central projection 4b' of the diaphragm receiver 9 is connected to the lower center hole 9a (the first
3 and 14), the centering with the diaphragm receiver 9 is ensured, and the diaphragm receiver 9 is able to slide smoothly on the inner peripheral surface of the lower part of the spring protection cylinder 2. Since the valve is guided by the lift valve rod 6, the valve can be opened smoothly when there is no pressure, and variations in the blowing pressure due to this operation will not occur. In addition, since the convex part on the lower surface of the spring protection cylinder 2 is fitted concentrically with the valve body 1, there is no eccentricity between the valve seat 1a and the valve body 4, and when the valve opens in the event of overpressure. In this case, the valve opening operation is performed with the lower surface (contact surface) of the valve body 4 always being parallel to the end surface of the valve seat 1a, without causing problems such as friction on the sliding portion of the outer periphery of the diaphragm receiver 9.

In general, the diaphragm seal disc type safety relief valve according to the present invention has a high blowout pressure, the outlet piping is thin, or the horizontal piping is long, and the incompressibility of the diaphragm seal disc type safety relief valve, especially when the fluid used is a liquid, may deteriorate. As a result, the minute vacuum created during the flow of the outlet piping affects the diaphragm, causing breathing action, which in severe cases can cause vibration. If some air is mixed in the liquid on the outlet side, this type of phenomenon can be prevented from occurring, so a vacuum breaker valve 17 is installed in the flow path on the outlet side near the outlet, as shown in FIG. ing. This vacuum breaker valve 1
7 includes a valve seat body 19, a valve body 20, and a valve body spring 21 that presses the valve body 20 in the valve closing direction; It consists of The above-mentioned "breathing action" decreases as the diameter of the movable part of the diaphragm 10 (the diameter of the diaphragm receiver 9) decreases. Therefore, according to the present invention,
The diameter of the diaphragm receiver 9 is made as small as possible to approximate the diameter of the valve seat. This also helps overcome the drawbacks of the diaphragm shape, which is susceptible to back pressure (outlet side pressure). Also, this “breathing action”
As shown in FIG. 5, the larger the outlet side volume V of the valve box 1, the smaller the amount. For this reason, the bottom 1d of the valve seat 1a on the outlet side is lowered all the way to the lower surface 1c of the outlet. Furthermore, the diaphragm 10 is formed as thin as possible because it is preferable to be thin in terms of performance (airflow amount), and in consideration of "breathing operation", the movable part is provided with a convolution as shown in Fig. 10. 10a is provided to connect the diaphragm 10.
is designed so that it does not come out into the flow path. In addition, according to the present invention, since the valve seat position is selected high, residual water and foreign matter after being blown out do not accumulate near the valve seat, and contact between the valve body 4 and the valve seat surface is performed with a soft touch. Because of this, it is possible to maintain the initial performance even after long-term use.

Furthermore, according to the present invention, as shown in FIG.
Since the adjusting screw 7 is of a non-rising type (it does not move up or down even when the adjusting screw 7 is turned) and its top surface is formed wide, the top surface of the adjusting screw 7 can be used as the operating platform of the test lever 11. (See FIG. 6), and the procedure for adjusting the adjustment spring 5 is much simpler than that of the conventional structure, and the structure is also simple. That is, as shown in FIG. 5, the spring receiver 5a is screwed onto the adjusting screw 7, but as can be seen from FIG. Since it is fitted into the inside 2d of the circular protection tube 2 and is restricted from rotating, when the adjustment screw 7 is turned, only the spring receiver 5a moves up and down, and the adjustment spring 5
The elasticity of can be adjusted. On the other hand, with the conventional structure, in order to adjust the elasticity of the adjustment spring 5, the pin 12 is pulled out, the lever 11 is removed, and the cap 8 is removed.
It was necessary to remove the back pressure adjusting plate 8' in Figure 4, loosen the lock nut (which is a lock bolt in Figure 4, and not in the one in Figure 2), and then turn the adjustment screw 7. . Note that the contour of the spring receiver 5a and the cross-sectional shape of the inside 2d of the protective tube 2 are not limited to round quadrangles if they are not perfectly circular, but may also be polygons such as squares, hexagons, octagons, etc., or perfectly circular with part of the arc missing. Furthermore, as shown in FIG. 8 or 9, a protrusion 5a' or a recess 5a'' may be provided at the outer edge of the spring receiver 5a, and the cross section of the interior 2d of the spring protection tube 2 may be shaped like this, respectively. In addition, according to the present invention, since the adjusting screw 7 itself does not move up or down when adjusting the adjusting spring 5 as described above, the valve opening amount by the test lever 11 changes due to the adjustment. Therefore, the adjustment range of the blowout pressure is not significantly restricted at all.In addition, according to the present invention, the inside of the spring protection cylinder 2 is completely isolated from the fluid path by the valve body assembly as described above. Moreover, since it is reliably insulated, there is no need to drill a hole 2c as shown in FIG. It can be manufactured at low cost.

Although the explanation above has mainly been based on the case where a liquid is used as the fluid, it goes without saying that the same effect can be achieved even when a gas is used.
Further, since the operation of the safety relief valve itself is as explained in connection with the conventional example, detailed explanation thereof will be omitted.

As described above, according to the present invention, the procedure for adjusting the adjustment spring is significantly simplified, and it is possible to provide a high-performance safety relief valve in which the valve opening amount by the test lever does not change due to the adjustment. .

[Brief explanation of drawings]

1 to 4 are vertical cross-sectional views showing conventional examples of safety relief valves with different structural types, respectively, and FIG.
The figure is a vertical sectional view showing one embodiment of the safety relief valve according to the present invention, FIG. 6 is a top plan view of the above embodiment, and FIG. 7 is a top plan view of the above embodiment.
The figure is a sectional view taken along the line -- of FIG. 5, FIGS. 8 and 9 are sectional views showing other examples related to FIG.
Figure 0 is an enlarged view of the valve seat and valve body shown in Figure 5.
FIG. 11 is a central vertical cross-sectional view of the reinforcing metal fitting, FIG. 12 is a bottom view of the reinforcing metal fitting, FIG. 13 is a central vertical cross-sectional view of the diaphragm receiver, and FIG. 14 is a bottom view of the diaphragm support. 1...Valve box, 2...Spring protection tube, 4a...Reinforcement metal fittings, 4a...Through hole, 4a...Protrusion, 4b...Elastic body portion, 5...Adjustment spring, 6...Lifting valve rod, 7...
...Adjustment screw, 9...Diaphragm holder, 10...Diaphragm, 11...Test lever.

Claims (1)

[Scope of utility model registration request] A valve body including a connection port, a valve seat, and an air outlet, a spring protection tube connected to the valve body, and a spring protection tube that is held between the valve body and the spring protection tube to keep the inside of the valve body and the spring protection tube liquid-tight. - A diaphragm that can be airtightly partitioned, a valve element and a diaphragm receiver coupled to the diaphragm, an adjustment spring that can elastically press the valve element in the valve closing direction, and an adjustment that can adjust the elasticity of the adjustment spring via the spring support. a screw, and a valve lift rod that is slidably inserted through the adjustment screw and can move the valve body in the valve opening direction;
In a safety relief valve equipped with a test lever that is pivotally connected to the lift valve rod and can open the valve body, the spring receiver is screwed onto the adjustment screw so that it cannot rotate, and the adjustment screw is tightened. A safety relief valve characterized in that it is of a non-rising type and has a wide top surface so that the test lever comes into contact with the top surface of the adjustment screw.