JP4390281B2 - Check valve - Google Patents

Description

  The present invention relates to a check valve used for, for example, a high-pressure plunger pump of an atomizer.

  The atomization device is used to homogenize fluids such as material material collision, pulverization or emulsification and fine particle dispersion. For example, in the device configuration shown in FIG. Various slurry liquids are directly pressurized using two high-pressure plunger pumps and injected into a chamber in which a collision space is formed.

  In such an atomizer, normally, a suction pipe (IN side) from the feed pump of the raw material tank to the cylinder of the high pressure plunger pump and a liquid feed pipe (OUT side) communicating from the cylinder to the chamber are in the flow path. Each has a check valve. These check valves include, for example, as shown in FIG. 5, an annular packing 35 made of an elastic material such as urethane elastomer disposed in a through passage 39 of the valve body 32, stainless steel, cemented carbide, ceramics, and the like. An annular valve seat 34 made of a super-hard material and a ceramic ball 37 as a spherical movable valve body are mainly constituted.

  In a natural state, the ceramic ball 37 is pressed against the valve seat surface on the inlet side formed by the valve seat 34 and the packing 35 by the biasing force of the first spring 38 from the low-pressure part side (outlet side), and is seated and adhered. This contact state prevents the slurry liquid from leaking to the inlet side. Furthermore, there is also a ceramic ball 37 that is closely attached to the valve seat 34 without any gaps, thereby preventing the packing 35 from “extending damage” to the low pressure portion side due to high pressure (see, for example, Patent Document 1).

JP 2000-283309 A

  However, in conjunction with the recent increase in demand for ceramic electronic components, for strongly alkaline slurries containing hard particles such as barium titanate that are required to have high performance as electronic component materials, In the conventional check valve, due to the following problems, high-pressure slurry is likely to leak due to damage to the packing, poor sealing in the sealed state of the valve body, and the like.

  For example, the contact surface of the valve seat on which the ceramic ball is repeatedly pressed will also cause the hard particles of the raw material to be sandwiched between the ball and the ball. It was. However, if the valve seat is made of stainless steel, cemented carbide, or ceramics with high hardness, if the wear resistance is increased, chipping is likely to occur, which may lead to overall breakage.

  Further, when the high pressure plunger moves forward, internal pressure acts on the OUT side valve seat, but brittle materials such as cemented carbide and ceramics are broken by the tensile stress caused by the internal pressure. For this reason, there is also a structure that prevents breakage by balancing by applying a pressure increased from the outer diameter portion of the valve seat via an elastic body such as an elastomer. However, because the elastomer that regulates the outer diameter of the valve seat is an elastomer, it may move in the circumferential direction, causing an excessive load at a position shifted when contacting the ball, causing chipping. It was. On the other hand, since only the external pressure acts on the OUT side valve seat when the plunger is retracted, a certain degree of strength is required for compression.

  Also, urethane elastomer packing is easier to deform than plastic, has excellent sealing properties against agglomerated powder and large particles, has high tear strength, and can withstand high pressure, so it can be used as a check valve packing for atomizers. Although it was suitable, in an aqueous solution, particularly in an alkaline solution of 40 ° C. or higher, there is a drawback that the volume is reduced by hydrolysis. For example, as shown in FIG. So-called back leakage of the liquid may occur. This is a liquid leak caused by the annular packing 35 being deformed by the pressing force applied by the valve body holder 31.

  In view of the above problems, the object of the present invention is to prevent damage to the valve seat and packing even in the case of feeding a slurry of hard particles such as barium titanate in the high-pressure plunger pump of the atomizer. An object of the present invention is to provide a check valve that can maintain a good sealing performance of a valve body in a stopped state and can have a longer life than the conventional one.

  In order to achieve the above object, a check valve according to the invention described in claim 1 is provided in a pipe flow path for slurry feeding that communicates with a cylinder of a high-pressure plunger pump, and a forward flow that flows in from an inlet. A valve body having a through-flow passage through which slurry liquid passes from the one-end side inlet to the other-end-side outlet, and a through-flow passage in the check valve that prevents the reverse flow from the outlet toward the inlet side An annular valve seat member disposed inside and having one end communicating with the through-flow passage inlet and the other end opened to the through-flow passage outlet, and a valve seat formed in a tapered shape at the opening edge on the other end side of the valve seat member A movable valve body seated on the surface from the outlet side, and a first spring member that urges the movable valve body from the outlet side to press the valve seat surface to seal the through-flow path, The surface is composed of an inner region and an outer region continuous with each other, and the valve The member has an annular valve seat made of a high hardness member that forms the valve seat surface of the inner region, and an annular packing made of an elastic body that forms the valve seat surface of the outer region on the outer periphery of the annular valve seat. And a valve seat presser for positioning and fixing the valve seat from the inlet side of the annular valve seat, and a back leakage prevention means for pressing and clamping at least a part of the annular packing on the inlet side.

  A check valve according to a second aspect of the present invention is the check valve according to the first aspect, wherein the back leakage prevention means includes a part of the annular valve seat presser. .

  A check valve according to a third aspect of the present invention is the check valve according to the first or second aspect, wherein the check valve is disposed so as to be axially movable in the through-flow path, and the movable valve body is arranged in an outer circumferential direction. And a tip end portion of which comes into contact with the annular packing by a biasing force from the outlet side to the inlet side by the second spring member, and at least a part of the annular packing is movable. The valve body holder further includes a substantially cylindrical valve body holder that is pressed against the valve body, and the valve body holder includes an annular portion having a tapered surface that comes into contact with the annular packing, and supports the tubular portion at an equiangular interval to the inside. And a plurality of arm portions forming a cavity.

The check valve according to the invention described in claim 4 is the check valve according to any one of claims 1 to 3, wherein the valve seat uses nickel as a binder, and a fracture toughness value _K1C is It consists of a cemented carbide which is 10-20 MPa · m ^1/2 .

  A check valve according to a fifth aspect of the present invention is the check valve according to any one of the first to fourth aspects, wherein the annular packing is made of an ether-based urethane elastomer having a Shore hardness of Hs 80 to 95. It will be.

  In the check valve of the present invention, the valve seat is formed in a tapered shape at the opening edge on the other end side of the annular valve seat member in which the through passage of the valve body is sealed by seating the movable valve body from the outlet side. The annular valve seat, which is composed of an inner region and an outer region that are continuous with each other and forms a valve seat surface in the inner region, is engaged with the entire edge of the inlet side edge by the annular valve seat retainer. In order to prevent the valve seat from shifting in the valve body by positioning and fixing, even if the valve seat itself is made of a brittle material, when the movable valve body comes into contact, the tip of the valve seat is excessively large due to the shift. The occurrence of chipping due to the load is avoided, and the annular packing forming the valve seat surface in the outer region is pressed and sandwiched at least partially on the inlet side by the back-leakage prevention means. The ring-shaped packing is pressed from the inlet side and is pressed and adhered to the surrounding member region such as the valve body over the outer peripheral region, preventing back leakage of the slurry liquid, and the sealing performance of the valve body in the sealed state is more improved than before. It can be maintained well and the life as a check valve can be extended.

  The present invention relates to a check valve for a high-pressure plunger pump of an atomizer, in which a slurry liquid of a valve body is disposed in a through-flow passage through which one end-side inlet passes to the other-end outlet, and one end is connected to the through-flow passage inlet. The movable valve body seated on the valve seat surface formed in a taper shape at the opening edge of the other end side of the annular valve seat member that communicates and the other end opens to the outlet of the through flow passage is connected to the outlet side by the first spring member. The through-flow path is sealed by being pressed from the valve seat surface, the valve seat surface is composed of an inner region and an outer region that are continuous with each other, and the valve seat member is An annular valve seat made of a high-hardness member that forms the valve seat surface of the inner region, and an annular packing made of an elastic body that forms the valve seat surface of the outer region on the outer periphery of the annular valve seat, Engage the entire circumference of the inlet side edge of the annular valve seat And, those having a valve seat retainer for positioning and fixing said valve seat, and a back leakage preventing means for pressing sandwiching at least a portion of the annular packing on the inlet side.

  Therefore, in the present invention, since the valve seat is fixed to the valve seat retainer in the fitted state, the valve seat is not displaced in the valve body, and the valve seat itself is made of a brittle material. However, at the time of contact of the movable valve body, not only the occurrence of chipping due to the excessive load on the tip due to the deviation is avoided, but also at least a part of the annular packing is pressed and clamped on the inlet side by the back leakage prevention means. Therefore, the contact portion of the annular packing with the valve body is pressed well against the valve body to prevent back leakage of the slurry liquid, and the sealing performance of the valve body in a sealed state can be maintained better than before, and the check The life of the valve can be extended.

  Examples of the high-hardness member constituting the annular valve seat in the present invention include cemented carbide, Co-based alloy (Stellite), precipitation hardening type high silicon steel (Silicolloy), and the like, and are not particularly limited. .

  As the back leakage prevention means of the present invention, a dedicated member for pressing and clamping a part of the annular packing may be provided separately, but in this case, the design as a check valve becomes complicated. It is desirable to use a part of the annular valve seat retainer. For example, in the contact area from the annular packing inlet side of the valve seat presser, a protruding portion is provided so as to sandwich a part of the annular packing with respect to the upper surface of the annular valve seat, and the annular packing has a shape corresponding thereto. That is, an annular packing shape may be formed so that a fitting portion is formed on the inlet side between the protruding portion of the valve seat presser and the upper surface of the annular valve seat.

  In addition, it is simple in configuration that the movable valve body is spherical as in the prior art, and the valve seat surface conforms to its outer shape and accepts the movable valve body. Various shapes can be adopted as long as they can be seated and seal the through passage of the valve body. For example, a configuration in which a substantially conical movable valve body having a vertex on the inlet side and a bottom surface on the outlet side and a valve seat surface are fitted to each other in a seated state. Moreover, chipping of the valve seat can be prevented by chamfering the ridge portion of the edge contacting the movable valve body of the annular valve seat. In this case, it is more desirable that the chamfer is a curved surface.

  Further, conventionally, the check valve for the high pressure plunger pump of the atomization apparatus has a cavity at the inlet side end portion for holding the movable valve body from the outer peripheral direction in the valve main body passage. A substantially cylindrical valve body holder that abuts against the annular packing by a biasing force from the outlet side to the inlet side by the spring member and presses at least a part of the annular packing against the movable valve body is movable in the axial direction Has been placed.

  In conventional valve body holders, if the movable valve body is held so as to be regulated by the entire outer periphery, the slurry liquid cannot pass outside the valve body holder, resulting in trouble, so there is a problem between the movable valve body and the holder. A gap of about 2 mm was provided in the radial direction. However, when the high-pressure plunger pump of the pressure intensifier is vertically installed as shown in FIG. 4 and the check valve is oriented sideways along the horizontal direction, as described above, between the valve element holder and the valve element. If there is a large gap, the valve body moves closer to the lower side, so that it is not seated coaxially on the valve seat surface, which may result in poor sealing.

  Therefore, the valve body holder is configured to have an annular portion having a tapered surface that contacts the annular packing, and a plurality of arm portions that support the annular portion at equal angular intervals to form the cavity therein. As a result, the cavity forming portion that holds the outer periphery of the movable valve body is formed with an opening through which the slurry liquid can flow between the arm portions. Therefore, the movable valve body can be seated on the center of the valve seat surface along the axial center to improve the sealing performance.

  If the number of arms is too large, not only will the opening area for slurry liquid flow become narrow, but the construction will be complicated and it will be difficult to manufacture the members. Since the balance of the holding of the body holder is deteriorated, an appropriate one may be selected according to the actual movable valve body and the size of the valve body holder. For example, a configuration that has three arms as the structure that allows easy opening of the slurry liquid for good circulation and at the same time can hold the movable valve body in the center of the cavity. Is mentioned.

Further, by making the valve seat itself excellent in both hardness and corrosion resistance, it is possible to provide chipping resistance and to better prevent damage due to external pressure. For example, conventionally, a valve seat has been made of cemented carbide, but this is made of cobalt as a binder. Therefore, if the valve seat is made of a cemented carbide with a high toughness having a fracture toughness value K _{1C of 10} to 20 MPa · m ^1/2 with nickel as the binder, the above-mentioned corrosion resistance is improved, and as a check valve This contributes to further prolonging the service life of the product.

  In addition, it is desirable to use a member that has both a reliable sealing property and an appropriate strength and can extend the life of the annular packing. For example, urethane elastomers with excellent mechanical properties such as tear resistance and wear resistance have been used for the check valve packing of high-pressure plunger pumps. Uses ether-based urethane elastomers with higher water resistance and impact resilience than elastomers, especially those with a Shore hardness of Hs 80-95, and ensures excellent strength against particles with a diameter of about 2 to several tens of micrometers while ensuring strength and durability. Sex is also obtained.

  If the outer valve seat surface of the annular packing is formed along the outer surface shape of the movable valve body to be seated, both surfaces are more likely to be in close contact with each other, leading to an improvement in sealing performance. For example, if the movable valve body is spherical, the outer valve seat surface may be a concave curved surface along the spherical shape.

  As an embodiment of the present invention, FIGS. 1 and 2 show a check valve for a high-pressure plunger pump constructed using a silicon nitride ceramic ball as a movable valve body. FIG. 1 is a partial longitudinal sectional view showing a structure of a seating region for an annular valve seat member of a ceramic ball of a check valve according to this embodiment. 2A and 2B are configuration diagrams of the valve body holder of the check valve, wherein FIG. 2A is a side view of the valve body holder, FIG. 2B is a cross-sectional view of the valve body holder taken along the line AA, and FIG. It is a BB cross-sectional arrow view of a body holder.

  For example, in the atomization apparatus as shown in FIG. 4, the check valve of the present embodiment communicates from the feed slurry pump of the raw material slurry tank to the cylinder of the high pressure plunger pump and the cylinder to the chamber. These are respectively provided in the flow path with the liquid supply pipe (OUT side).

  The basic check valve 1 is similar in structure to the conventional one shown in FIG. 5, for example, and the slurry of the valve body 2 fixed in the pipe 100 communicating with the cylinder of the high-pressure plunger pump is supplied from one end side inlet. With respect to the annular valve seat member 3 that is disposed in the through flow passage 9 that passes to the other end side outlet and that has one end communicating with the inlet side of the through flow passage 9 and the other end opening on the outlet side of the through flow passage 9. The ceramic ball 7 seated on the valve seat surface formed in a taper shape at the opening edge on the other end side of the valve seat member 3 is urged from the outlet side by the first spring member 8 and pressed against the valve seat surface. In this way, the through-flow path 9 is sealed.

  The annular valve seat member 3 includes a cemented carbide annular valve seat 4 disposed on the inner side of the valve body 2 and the through passage 9 near the central axis, and an elastic member disposed on the outer peripheral side of the valve seat 4. The inner side valve seat surface (inner valve seat surface) 4x and the outer region valve seat, each of which has an opening end face on the outlet side continuous with each other and serves as the valve seat surface of the annular valve seat member 3. A surface (outer valve seat surface) 5x is formed. The valve seat 4 is not limited to a cemented carbide alloy, and may be composed of other high-hardness members such as a Co-based alloy (Stellite) or a precipitation hardening type high silicon steel (Silicolloy).

  The ceramic ball 7 is held in a cavity 11 provided on the inlet side of a substantially cylindrical valve body holder 10 that is arranged so as to be movable in the axial direction in the through passage 9. The first spring member 8 is The ceramic ball 7 is pressed and urged toward the valve seat surface in the valve body holder 10. Further, the valve element holder 10 is further urged from the inlet side to the outlet side by a second spring member (not shown).

  As described above, in the check valve 1, the valve seat surface on which the ceramic ball 7 is seated includes the annular packing 5 and the annular valve seat 4. In this embodiment, the annular valve seat is, for example, It is positioned and fixed from the inlet side by a valve seat retainer 6 made of stainless steel or the like.

  That is, the valve seat presser 6 has a corresponding position on the outlet side of the annular valve seat 4 that is in contact with the end edge of the annular valve seat 4 over the entire circumference. The valve seat 4 is fixed by pressing the valve seat 4 at the upper part on the inlet side through the portion 5y. Therefore, in this check valve 1, the valve seat 4 fixed by the valve seat retainer 6 is not displaced in the valve main body 2, so an excessive load is applied to the tip portion due to the displacement when the ceramic ball 7 contacts. The occurrence of chipping due to this can be avoided, and the service life of the valve seat 4 and the check valve 1 can be extended as a result.

  Further, in this example, in order to further prevent chipping, the edge ridge portion of the valve seat 4 which is surrounded by a circle (◯) T in FIG. Thereby, the lifetime of the valve seat 4 can be further extended.

  On the other hand, the annular packing 5 is disposed in close contact with the outer peripheral region of the valve seat 4 so as to regulate the outer diameter of the valve seat 4, and the outer peripheral surface of the outlet side tip is the tapered inlet side tip of the valve body holder 10. An inclined surface for receiving the surface is provided, and the tip inner peripheral surface of the annular packing 5 is pressed against the outer peripheral surface of the ceramic ball 7 by pressing of the inlet side front end surface of the valve body holder 10, thereby closely contacting the ceramic ball 7. It is the structure which improves property and obtains a more reliable sealing state.

  Further, the annular packing 5 has a shape in which the inlet side branches in a substantially Y shape, and one branch portion 5y is formed between the outer peripheral surface of the inlet side of the annular valve seat 4 and the protruding portion 6x of the valve seat presser 6. Since the annular packing 5 is pressed from one branch portion 5y and the other branch portion is pressed and brought into close contact with the valve body 2 by this pressing and clamping force, the slurry in the contact area with the valve body 2 is brought into a sandwiched state. So-called back leakage of the liquid is avoided, and a better sealed state by the check valve 1 is obtained.

  Further, as shown in FIG. 2, the valve body holder 10 in this embodiment includes an annular portion 13 having a tapered surface 12 that contacts the annular packing 5, and supports the annular portion 13 at equal angular intervals. It has three arm portions 14 that form the cavity 11. Accordingly, the cavity 11 that surrounds the outer periphery of the ceramic ball 7 is formed with the opening 15 through which the slurry liquid can sufficiently flow between the arm portions 14. It was not necessary to provide a wide gap with the ball, and the cavity 11 portion surrounded by the arm portion 14 could be regulated in the proximity of the outer peripheral surface of the ceramic ball 7.

  For example, in the conventional valve body holder, the inner diameter of the cavity forming portion of the holder is 14.7 mm with respect to a ceramic ball having a diameter of 12.7 mm, and there is a gap of 2 mm at the maximum, but in this embodiment, With respect to the ceramic ball 7 having a diameter of 12.7 mm, the maximum inner diameter between the arm portions 14 of the cavity forming portion was 13.1 mm, and the gap between them could be suppressed to about 0.4 mm at the maximum. In this way, the cavity forming portion formed by the arm portion 14 of the valve body holder 10 can be held close to the outer peripheral surface of the ceramic ball 7 so that the ceramic ball 7 is centered on the valve seat surface along the axis. It is possible to improve the sealing performance.

  In addition, if the inner valve seat surface 4x of the valve seat 4 in the present embodiment is a concave curved surface along the outer peripheral shape with the ceramic ball 7, the sealing performance can be further improved. For example, when the ceramic ball 7 has a spherical shape with a diameter of 12.7 mm, the inner valve seat surface 4 x can be more closely attached if the rounded radius R is 6.35 mm. Of course, the outer valve seat surface 5x of the annular packing 5 may also be a concave curved surface along the outer peripheral shape of the ceramic ball 7 in the same manner.

  Regarding the check valve 1 having the above-described configuration, the check valve when the atomization treatment of barium titanate is performed by incorporating it under the two high-pressure plunger pumps constituting the intensifier of the atomizer of FIG. The life evaluation was performed in comparison with the conventional type similar to FIG. The results will be described below.

  First, atomization occurs when a conventional check valve is arranged at a predetermined position (IN side and OUT side) of both high-pressure plunger pumps in FIG. 4 and when a check valve according to the configuration of this embodiment is arranged. Processing is performed and the life is reached when malfunction occurs.

In the conventional type, the packing is made of ester urethane elastomer and the valve seat is made of SUS630 (conventional type 1), and the packing is made of ether-based urethane elastomer resistant to alkali and the valve seat is made of SUS630 (conventional type). 2) and the packing is made of ether urethane elastomer and the valve seat is made of WC-Ni cemented carbide (conventional type 3), and the check valve according to the present embodiment has the annular packing 5 resistant to alkali. The valve seat 4 is made of an ether urethane elastomer and is made of a WC-Ni cemented carbide. WC-Ni type cemented carbide used in the valve seat are all fracture toughness value _{K 1C} is 10 to 20 MPa ^{· m 1/2.}

  In the atomization process, each high-pressure plunger pump feeds raw material slurry into the chamber at 245 MPa and a flow rate of 0.73 kg / min. The slurry collides with each other in the chamber, and after the collision, the slurry is recovered and sent to the chamber again. The collision process is repeated multiple times.

  Specifically, 6 kg of barium titanate plus 14 kg of water = 20 kg (30 wt%, pH 12.4) is taken as one lot of slurry, and the processing time of one lot and eight passes (20 kg × 8 ÷ 0.73 kg / min ÷ 60 min =) The processing speed was about 3.5 hours. These were performed continuously. The results are shown in Table 1.

  As is clear from the results of Table 1, first, in the check valve having the same configuration provided with the valve seat made of the same material, the conventional type 1 ether type urethane compared to the case where the conventional type 1 packing is an ester type urethane elastomer. In the case of elastomer, the life was doubled. This is due to the fact that the ether-based urethane elastomer is resistant to alkali and the high durability of the packing material is exhibited in the atomization of a strong alkali slurry having a pH of 12 or higher. In addition, these check valves malfunctioned because the packing was broken and the valve seat was cracked.

  Furthermore, in the conventional type 3, when the valve seat was made of WC-Ni cemented carbide, the packing was damaged 80 hours after the start of the atomization treatment, but at that time the valve seat was not damaged and only the packing was used. The lifetime of replacement was 110 hours. On the other hand, in the configuration of the present embodiment type, only the packing was damaged 80 hours after the start of the atomization treatment, and the valve seat was extended to 160 hours and longer than the conventional type by replacing the packing. .

  From this result, it was confirmed that the check valve according to the present example can be expected to prolong the life of the valve itself by increasing the life of the valve seat as compared with the conventional type in the atomization of the hard particle slurry. This is because, in the check valve of the present embodiment, the valve seat 4 is positioned and fixed by the valve seat presser 6 and is not displaced when contacting the ceramic ball 7, and chipping is caused by applying an excessive load partially due to the displacement. This is because the intrusion of the high-pressure slurry liquid between the members is reduced by preventing the back leakage of the annular packing 5 at the same time.

  As described above, in the check valve according to the present embodiment, in addition to the above-described configuration, the slurry is hard particles by selecting a suitable material for each member such as the annular valve seat and the annular packing. In addition to being strong alkaline, it can maintain a sufficiently sealed state for a longer period and functions well as a check valve even for raw material slurries that have been difficult in conventional atomization equipment. can do.

  In the above embodiment, as a back leakage prevention means, a part (branch part) of the annular packing is pressed and clamped between a part (protruding part) of the valve seat presser and the inlet side outer peripheral surface of the annular valve seat. However, as shown in FIG. 3, one of the substantially Y-shaped branch portions 25 y of the annular packing 25 is pressed and clamped between the protruding portion 26 x of the valve seat retainer 26 and the annular valve seat 24. As long as it functions as a leakage prevention means, the annular valve seat 24 and the valve seat retainer 26 may be integrally formed of the same member.

  In this case, the check valve 21 shown in FIG. 1 has the same configuration as that of the check valve 1 shown in FIG. 1 except that the annular valve seat 24 and the valve seat retainer 26 are integrated. Similar to 1, the sealing performance in the sealed state is high, and it has a longer life than before.

It is a schematic longitudinal cross-sectional view which shows the structure of the non-return valve by one Example of this invention. It is a schematic block diagram explaining the valve body holder of this check valve, (a) is a side view, (b) is an AA sectional arrow view, (c) is a BB sectional arrow view. It is a schematic longitudinal cross-sectional view which shows the structure of the non-return valve by the other example of this invention. It is a schematic whole block diagram which shows an example of the atomization apparatus provided with the pressure booster by a high pressure plunger pump. It is a schematic longitudinal cross-sectional view which shows an example of the conventional check valve.

Explanation of symbols

1, 21, 30: Check valve 2, 22, 32: Valve body 3, 23: Annular valve seat member 4, 24, 34: Annular valve seat 4x, 24x: Inner valve seat surface 4y: Inlet side edge corner 4z: Outlet side outermost edges 5, 25, 35: annular packing 5x, 25x: outer valve seat surface 5y, 25y: annular packing branching portion 6, 26: valve seat retainer 6x, 26x: protrusions 7, 27, 37 : Ceramic balls 8, 28, 38: First spring members 9, 29, 39: Through passage 10, 31: Valve body holder 11: Cavity 12: Tapered surface 13: Annular part 14: Arm part 100: Piping

Claims (5)

A non-return check that is provided in a pipe flow path for slurry feeding that communicates with the cylinder of the high-pressure plunger pump, and allows the forward flow that flows in from the inlet to pass through the outlet and prevents the reverse flow from the outlet toward the inlet. In the valve
A valve body having a through-flow path through which slurry liquid passes from one end side inlet to the other end-side outlet, and disposed in the through-flow path, one end communicates with the through-flow path inlet and the other end opens to the through-flow path outlet. An annular valve seat member, a movable valve body seated from the outlet side on a valve seat surface formed in a tapered shape at the other end opening edge of the valve seat member, and urging the movable valve body from the outlet side A first spring member that presses against the valve seat surface and seals the through flow path,
The valve seat surface includes an inner region and an outer region continuous with each other, and the valve seat member includes an annular valve seat made of a high-hardness member forming a valve seat surface of the inner region, and the annular valve seat An annular packing made of an elastic body forming a valve seat surface of the outer region on the outer periphery;
A valve seat retainer for positioning and fixing the valve seat from the inlet side of the annular valve seat;
A check valve for a high-pressure plunger pump, further comprising back leakage prevention means for pressing and clamping at least a part of the annular packing on the inlet side.   The check valve according to claim 1, wherein the back leakage prevention means includes a part of the annular valve seat presser. The cavity is disposed in the through-flow passage so as to be movable in the axial direction, and has a cavity for holding the movable valve body from the outer peripheral direction at the end on the inlet side. Further comprising a substantially cylindrical valve body holder whose front end abuts against the annular packing and presses at least a part of the annular packing against the movable valve body,
The valve body holder includes an annular portion having a tapered surface that contacts the annular packing, and a plurality of arm portions that support the tubular portion at equal angular intervals to form the cavity therein. The check valve according to claim 1 or 2. 4. The valve seat according to claim 1, wherein the valve seat is made of a cemented carbide having nickel as a binder and a fracture toughness value K _{1C of 10} to 20 MPa · m ^1/2. Check valve. The check valve according to any one of claims 1 to 4, wherein the annular packing is made of an ether-based urethane elastomer having a Shore hardness Hs of 80 to 95.

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