CN203348645U - Venturi tube type low-resistance backflow prevention device - Google Patents
Venturi tube type low-resistance backflow prevention device Download PDFInfo
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- CN203348645U CN203348645U CN 201320334806 CN201320334806U CN203348645U CN 203348645 U CN203348645 U CN 203348645U CN 201320334806 CN201320334806 CN 201320334806 CN 201320334806 U CN201320334806 U CN 201320334806U CN 203348645 U CN203348645 U CN 203348645U
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Abstract
The utility model discloses a Venturi tube type low-resistance backflow prevention device. The Venturi tube type low-resistance backflow prevention device is characterized in that an inlet check valve, an accelerating tube, a valve body and an outlet check valve are arrayed in sequence and are in the same central line after installation, the central line of a drainer is perpendicular to the central line of the inlet check valve, the accelerating tube, the valve body and the outlet check valve, the inlet check valve comprises a corresponding inner conical surface of a first connecting tube, a first valve clack matched with the inner conical surface, a first valve rod connected to the center of the valve clack, and a guide seat which is matched with the first valve rod and plays a role in guiding the first valve clack, the accelerating tube is a Venturi tube, the valve body is a right-angle tee joint, the outlet check valve is arranged in an enlarging hole in the downstream end of the valve body, and a water outlet hole is formed in the lower portion of the valve body. The drainer comprises a control chamber, wherein a lower valve main body which is connected with the water outlet hole is combined with a lower valve cover to form the control chamber, a drain valve is arranged in a cavity body of the lower valve main body, a valve rod of the drain valve penetrates through the control chamber, and a membrane is arranged at the lower end of the valve rod. Under any unfavorable work condition, the Venturi tube type low-resistance backflow prevention device has reliable separation performance, flow resistance losses can be greatly reduced, and the energy consumption is reduced.
Description
Technical field
The utility model relates to a kind of valve, relates in particular to a kind of low resistance force counter flow stop.
Background technique
Backflow preventer claims again dirty stream isolating valve, is a kind of safety features of polluted source while strictly preventing that the Drinking Water pipeline from occurring to reflux, and also can be applicable in other pipe-line system that does not allow medium to flow backwards.
The pattern of backflow preventer is more in the market, pressure reduction type backflow preventer is due to its function admirable, reliable operation, oneself is widely adopted, its typical structure means in the Chinese patent of publication number CN2442057, inlet check valve, intermediate cavity, outlet non-return valve and plug-in hydathode, consists of.But drag losses when the main deficiency of in use finding this structure is the medium circulation is larger, when velocity of medium is 3m/s, flow resistance loss reaches 0.07-0.10MPa/n, its main cause is for drain valve cuts out reliably, must make intake pressure be greater than the reposition force of drain valve, like this, the spring force of inlet check valve must design greatlyr.In order to realize the purpose of energy-saving and emission-reduction, many departments just are being devoted to reduce the research of loss of head.
Summary of the invention
The purpose of this utility model is: design in order to solve above-mentioned key problem in technology that a kind of both to have had the property cut off good, can significantly reduce again the Venturi tube-type spreader low resistance force counter flow stop of a kind of energy-conservation innovation of flow resistance.
Above-mentioned technical problem of the present utility model is mainly solved by following technical proposals: a kind of Venturi tube-type spreader low resistance force counter flow stop is characterized in that:
By inlet check valve, accelerating tube, valve body, outlet non-return valve and hydathode, formed; Described inlet check valve, accelerating tube, valve body, outlet non-return valve are sequentially arranged, and after installing, are same center line; Described hydathode is positioned at valve body lower end, and its center line is vertical with last center line;
Described inlet check valve comprises the corresponding inner conical surface of connecting tube one, with the flap one of described inner conical surface adaptation, is connected to the valve rod one at flap one center, and guide holder one that flap one play the guiding role adaptive with valve rod one; There is an elongated axial blind hole at described valve rod center, and root has some radial holes that are communicated with blind hole, in order to be communicated with the cavity between accelerating tube stage casing and flap one and guide holder one;
Described accelerating tube is Venturi tube, is arranged between inlet check valve and valve body, and the aperture of the aperture ratio inlet/outlet end in its stage casing is little;
Described valve body is a right angle threeway, in the reaming of its downstream, outlet non-return valve is installed, and the below of described valve body is provided with osculum, the valve seat that the annular sword limit of described osculum below periphery is drain valve;
Described hydathode comprises the lower valve body be connected with the osculum of valve body below, the control room that lower valve body and bottom flange are combined into, in described lower valve body (cavity), drain valve is housed, described drain valve valve rod penetrates control room, sealing gasket is equipped with in the valve rod upper end, and the diaphragm that control room is divided into to upper and lower two chambeies is equipped with in the valve rod lower end;
Be connected with conduit one between described water-inlet cavity I and drain valve control room cavity of resorption;
Be connected with conduit two between described accelerating tube stage casing and drain valve control room epicoele.
The technical solution of the utility model can also be further perfect:
As preferably, the front end of the flap one of described inlet check valve is smooth segment, and rear end is a frustum, and front end segment and connecting tube one inner conical surface contact position have groove, are provided with O-ring seals one in groove; Described flap one is held and is threaded one by one with valve rod, and the other end of valve rod enters the stage casing of accelerating tube; Be provided with spring one between described flap one groove relative with guide holder one, described spring one has certain pretightening force after installing; Gapped between the maximum endoporus of described flap one downstream and the corresponding cylindrical of guide holder one.
As preferably, the annular section between the maximum outside diameter of described inlet check valve frustum and connecting tube one downstream reaming is not less than the area of connecting tube one bore.
As preferably, described connecting tube one downstream has outside thread, and the accelerating tube upstream extremity has the internal thread coordinated with outside thread, and connecting tube one screws by screw thread with accelerating tube, and guide holder one is compressed and location.
As preferably, described accelerating tube comprises leading portion, back segment and stage casing, the undergauge section that described stage casing is, and the cone angle of described leading portion is 60 °, the cone angle of back segment is 20 °.
As preferably, have two elongated slots under described hydathode on the cylindrical wall of valve body, as the weep hole of discharge recirculation water; Described valve rod three is by the adjusting nut pilot hole and the guiding of the pilot hole on transverse partition that are arranged on lower valve body.
The beneficial effects of the utility model are:
Owing to adopting technique scheme, make backflow preventer no matter under which kind of disadvantageous operating mode, all there is reliable interrupting performance, can significantly reduce flow resistance loss, energy saving consumption again.
The accompanying drawing explanation
Accompanying drawing 1 is a kind of structural representation of the present utility model.
Description of reference numerals: 1, connecting tube one, 2, flap one, 3, O-ring seals one, 4, spring one, 5, guide holder one, 6, valve rod one, 7, O-ring seals two, 8 accelerating tubes, 9, O-ring seals three, 10, valve body, 11, flap two, 12, O-ring seals four, 13, spring two, 14, guide holder two, 15, O-ring seals five, 16, valve rod two, 17, connecting tube two, 18, O-ring seals six, 19, lower valve body, 20, adjusting nut, 21, guide plate, 22, locking nut, 23, spring three, 24, valve rod three, 25, diaphragm, 26, top board, 27, press table, 28, bottom flange, 29, sealing gasket, 30, pressing plate, 31, jump ring one, 32, ring washer one, 33, ring washer two, 34, O-ring seals seven, 35, conduit one, 36, conduit two,
M, intermediate cavity, L, weep hole, C, cavity, I, water-inlet cavity, W, lower valve body transverse partition;
P1, import hydraulic pressure, P2, import one-way valve downstream pressure, the hydraulic pressure of P3, accelerating tube undergauge section, P4, intermediate cavity pressure, P5, outlet pressure;
A, axial blind hole, b, radial hole.
Embodiment
Below by embodiment also by reference to the accompanying drawings, the technical solution of the utility model is further described in detail.
Embodiment:
Venturi tube-type spreader low resistance force counter flow stop as shown in Figure 1, by inlet check valve, accelerating tube 8, valve body 10, outlet non-return valve, and hydathode form.Front four that CB is installed is consistent, and the latter's center line is vertical with it.
Inlet check valve is comprised of the parts such as corresponding inner conical surface, flap 1, O-ring seals 1, spring 1, guide holder 1 and valve rod 1 of connecting tube 1.The front end of flap 1 is a smooth segment, and rear end is a frustum, and for reducing local resistance loss, the annular section between the maximum outside diameter of frustum and connecting tube one 1 downstream reamings is not less than the area of connecting tube one 1 bores, flap 1 and valve rod one 6 spiral shell knots.The Zhong， center, stage casing (undergauge section) that the head of valve rod 1 inserts accelerating tube 8 has an elongated axial blind hole a root that some radial hole b are arranged, in order to the cavity C of one 5 of the undergauge section that is communicated with accelerating tube 8 and flap 1 and guide holders.Therefore, under any operating mode, the hydraulic pressure of cavity C is identical with the hydraulic pressure P3 of undergauge section.O-ring seals 1 is tightly placed in the respective groove of flap one 2 front end segments, seals.Valve rod 1 is sliding to be fitted in the endoporus of guide holder 1. and the motion to flap 1 play the guiding role.The internal thread of the outside thread of connecting tube one 1 downstream and accelerating tube 8 upstream extremities screws, and guide holder 5 is compressed and location, the about 1mm in gap of the maximum endoporus of flap 1 and the corresponding cylindrical of guide holder 1, and O-ring seals 27 leaks in order to prevent medium.Spring 1 is arranged between the groove that flap 1 is relative with guide holder 1, certain pretightening force is arranged after installation, due to inlet check valve will be at flow less or medium when static two sides at flap 1 produce certain pressure reduction, to guarantee drain valve, close reliably, therefore pretightening force is larger, reliable for guaranteeing the drain valve sealing, the hydraulic pressure P ' that opens of inlet check valve is approximately drain shut valve hydraulic pressure P " 1.3 times; therefore; in the situation that do not supply water, the O-ring seals 1 on flap 1 is pressed on the corresponding inner conical surface of connecting tube 1 all the time.The cavity of flap one 2 upstream connecting tubes 1 is the water-inlet cavity I, and the water-inlet cavity I is communicated with the cavity of resorption of drain valve actuator (control room) diaphragm 25 by conduit 1, so the pressure of diaphragm 25 cavity of resorptions equates with the hydraulic pressure P1 of water-inlet cavity I all the time.Connecting tube one 1 upstream extremity flanges are connected with nut with the intake pipe flange, and the flange periphery is provided with the screw of setting pressure table ball valve.
Accelerating tube 8 is arranged between inlet check valve and valve body 10, and its downstream flange is connected with bolt with the respective flange of valve body 10, and prevents that with O-ring seals 39 medium from leaking.Accelerating tube 8 is actually a Venturi tube, and the aperture of the relative aperture inlet/outlet end in stage casing is little.At medium, hour, the pressure P 4 of the hydraulic pressure P3 of stage casing (undergauge section) and the hydraulic pressure P2 of inlet check valve downstream and valve body 10 intermediate cavity M is basically identical for static or flow; In, during large flow, because the flow velocity of the velocity ratio water-inlet cavity I of undergauge section is much higher, so P1 > > P3, in order to reduce to greatest extent the local resistance loss of the undergauge section of flowing through, the cone angle of its leading portion is 60 °, and the cone angle of back segment is 20 °, because the taper hole at rear portion progressively enlarges, pressure medium recovers gradually, and the pressure P 4 of intermediate cavity M is slightly less than P2.The undergauge section is communicated with diaphragm 25 epicoeles by conduit 2 35, so the pressure of diaphragm 25 epicoeles equates with the pressure P 3 of the undergauge section of accelerating tube 8 all the time.One boss is arranged on the cylindrical of undergauge section, and boss is provided with the screw of setting pressure table ball valve.
Valve body 10 is a right angle threeway, in the reaming of its downstream, outlet non-return valve is installed, and the working principle of outlet non-return valve is the same with general check valve, does not describe in detail here.Because 2 13, spring seals, so pretightening force is more much smaller than the spring 1 in inlet check valve.The outside thread of valve body 10 downstream and the corresponding internal thread of connecting tube 2 17 screw, and guide holder 2 14 is compressed and location, and O-ring seals 5 15 leaks in order to prevent medium.The flange of connecting pipe 2 17 right-hand members is connected with bolt with the flange of outlet conduit, and the flange periphery is provided with the screw of setting pressure table ball valve.The hollow cavity of valve body 10 is intermediate cavity M, with the difference of common pressure reduction type backflow preventer, is, intermediate cavity M does not communicate with the epicoele of drain valve control mechanism diaphragm, and the hydraulic pressure of intermediate cavity M is not controlled the action of drain valve.The below of valve body 10 is provided with osculum, and the annular sword limit of osculum below periphery is as the valve seat of drain valve.The lower flange of valve body 10 is connected with bolt with the upper flange of lower valve body 19, and prevents that with O-ring seals 6 18 medium from leaking.
Hydathode is comprised of parts such as lower valve body 19, sealing gasket 29, pressing plate 30, guide plate 21, adjusting nut 20, locking nut 22, spring 3 23, valve rod 3 24, O-ring seals 7 34, diaphragm 25, top board 26, press table 27 and bottom flanges 28.Have two elongated slots on the cylindrical wall of lower valve body 19, as the weep hole L of discharge recirculation water.Guide plate 21 use jump rings 31 are spacing, and the outside thread of the internal thread in its center hole and valve joint nut 20 screws, and adjusting nut 20 center is provided with pilot hole.Valve rod 3 24 connects pilot hole on lower valve body 19 transverse partition W and the pilot hole of adjusting nut 20, and sliding joining with it, two holes guiding thus during valve rod 3 24 motion, and the pilot hole of transverse partition W is provided with O-ring seals 7 34, in case medium leaks.The lower end of valve rod 3 24 is clamped in diaphragm 25 in control room by upper and lower pressing plate 26,27, the edge of diaphragm 25 is clamped by bolt between the flange of the lower flange of lower valve body 19 and bottom flange 28, diaphragm 25 is divided into upper and lower two chambeies by control room, and the motion of valve rod 3 24 is subject to the control of hydraulic pressure P1 and P3.Back-up ring 33 leans against on the shaft shoulder in valve rod 3 24 stage casings, between the ring washer 32 of ring washer 33 and valve joint nut 20 lower ends, is provided with spring 3 23, and its impacting force can be regulated by adjusting nut 20, regulates suitable rear with locking nut 22 lockings.Sealing gasket 29 use nuts, packing ring, be pressed on the pressing plate 30 that is positioned at valve rod 3 24 tops, sealing gasket 29, as the flap of drain valve, forms drain valve with the respective annular sword limit of valve body 10.
The utility model working principle
The key plan that Fig. 1 is interior each component of valve under obstructed regimen condition, now inlet check valve, outlet non-return valve are closed, and drain valve is opened, and intermediate cavity M, accelerating tube undergauge section and inlet check valve downstream communicate with weep hole L.During water supply, at first medium enters the water-inlet cavity I, and P1 raises, because the hydraulic pressure P ' that opens of inlet check valve closes hydraulic pressure P than drain valve " height; so the pressure that valve rod 3 24 overcomes spring 3 23 under low hydraulic pressure moves upward, until drain shut valve, now intermediate cavity M and weep hole L partition.After drain shut valve, import hydraulic pressure P1 continues to rise, and then inlet check valve, outlet non-return valve is opened, and supplies water downstream.P ' during due to small flow=1.3P " or in during large flow P3 be enough low values, therefore, when import hydraulic pressure P1 fluctuates downwards within the specific limits, drain valve can not opened.Hour, because the flow velocity of accelerating tube 8 undergauge sections raises seldom, so P3 equals pressure P 2 after the import one-way valve to flow, so act on the upper and lower pressure of diaphragm 25, is the pressure before and after inlet check valve.As previously mentioned, pressure reduction (P1-P2) can guarantee that drain valve is not opened in water supply process; When flow reach flow resistance is had materially affect in during large flow, because the flow velocity of accelerating tube 8 undergauge sections significantly raises, so P1 > > P3, pressure reduction (P1-P3) is even can guarantee between delivery period before and after inlet check valve that pressure reduction significantly reduces, while being even zero, drain valve can not opened yet; Low pressure P3 is by central through bore (axial blind hole) a and the radial hole b of valve rod 1 simultaneously, low pressure is introduced in cavity C, the pressure reduction of flap one 2 two sides significantly increases like this, act on power on the flap one 2 segments impacting force much larger than spring 1, valve port is all opened P1 ≈ P2, MEDIA FLOW is similar to zero through the pressure loss of inlet check valve, and, according to the design of Venturi tube, MEDIA FLOW is very little through the pressure loss of accelerating tube 8.Therefore, flow resistance loss greatly reduces in general, and this is also main innovate point of the present utility model.
Four various operating modes and prevent the Analysis on Mechanism that medium flows backwards
1, in water supply process, when import hydraulic pressure P1 descends, while (P1-P3) being less than setting value, drain valve is opened, and the undergauge section of accelerating tube 8 communicates with draining aperture L, and P3 reduces, as (P1-P3), while returning to setting value again, drain valve cuts out again, recovers normal water supply.
2,, when the downstream no user, medium stops flowing, the inlet/outlet closure of check ring, and P2=P3, if import hydraulic pressure is constant, exist pressure reduction, drain shut valve before and after inlet check valve.
3, fall too low or be zero as import hydraulic pressure P1, while even being negative value, inlet check valve is closed rapidly under spring one 4 effects, drain valve is opened fast under the effect of spring 3 23 simultaneously, air enters the spaces such as intermediate cavity M from weep hole L, form air partition, prevented the siphon refluence.
4, in the normal water supply process, for example, when certain reason (water hammer) causes that outlet pressure P5 significantly raises, while even surpassing import hydraulic pressure P1, if outlet non-return valve good seal now can not flow backwards; If seal break-off or flap are blocked by foreign material, high pressure water blows back into the undergauge section of intermediate cavity M and accelerating tube 8, causes P3 to raise; As (P1-P3), while being less than setting value, drain valve is opened, and the refluence medium, through intermediate cavity M, is discharged from weep hole L; If now the sealing of inlet check valve destroys simultaneously, because having entered intermediate cavity M, air forms air partition, and the water that therefore flows backwards can not enter water cavity.
If 5 inlet check valves seal heavy damages or are blocked by foreign material, inlet check valve almost in opened condition, now water inlet does not need to overcome spring pressure and directly enters intermediate cavity and discharges from weep hole L, runs into this situation and should stop immediately supplying water and overhauled.
From analysis known, under the utility model why not sharp operating mode in office, though the sealing of two safety check all lost efficacy, the danger at the medium pollution water source that can effectively prevent from flowing backwards.
Claims (6)
1. a Venturi tube-type spreader low resistance force counter flow stop is characterized in that:
By inlet check valve, accelerating tube, valve body, outlet non-return valve and hydathode, formed; Described inlet check valve, accelerating tube, valve body, outlet non-return valve are sequentially arranged, and after installing, are same center line; Described hydathode is positioned at valve body lower end, and its center line is vertical with last center line;
Described inlet check valve comprises the corresponding inner conical surface of connecting tube one, with the flap one of described inner conical surface adaptation, is connected to the valve rod one at flap one center, and guide holder one that flap one play the guiding role adaptive with valve rod one; There is an elongated axial blind hole at described valve rod center, and root has some radial holes that are communicated with blind hole, in order to be communicated with the cavity between accelerating tube stage casing and flap one and guide holder one;
Described accelerating tube is Venturi tube, is arranged between inlet check valve and valve body, and the aperture of the aperture ratio inlet/outlet end in its stage casing is little;
Described valve body is a right angle threeway, in the reaming of its downstream, outlet non-return valve is installed, and the below of described valve body is provided with osculum, the valve seat that the annular sword limit of described osculum below periphery is drain valve;
Described hydathode comprises the lower valve body be connected with the osculum of valve body below, the control room that lower valve body and bottom flange are combined into, in described lower valve body, drain valve is housed, described drain valve valve rod penetrates control room, sealing gasket is equipped with in the valve rod upper end, and the diaphragm that control room is divided into to upper and lower two chambeies is equipped with in the valve rod lower end;
Be connected with conduit one between drain valve control room cavity of resorption and water-inlet cavity;
Be connected with conduit two between described accelerating tube stage casing and drain valve control room epicoele.
2. Venturi tube-type spreader low resistance force counter flow stop according to claim 1, it is characterized in that: the front end of the flap one of described inlet check valve is smooth segment, rear end is a frustum, and front end segment and connecting tube one inner conical surface contact position have groove, are provided with O-ring seals one in groove; Described flap one is held and is threaded one by one with valve rod, and the other end of valve rod enters the stage casing of accelerating tube; Be provided with spring one between described flap one groove relative with guide holder one, described spring one has certain pretightening force after installing; The corresponding cylindrical adaptation of the maximum endoporus of described flap one downstream and guide holder one.
3. Venturi tube-type spreader low resistance force counter flow stop according to claim 2, it is characterized in that: the annular section between the maximum outside diameter of described inlet check valve frustum and connecting tube one downstream reaming is not less than the area of connecting tube one bore.
4. according to claim 1 or 2 or 3 described Venturi tube-type spreader low resistance force counter flow stops, it is characterized in that: described connecting tube one downstream has outside thread, the accelerating tube upstream extremity has the internal thread coordinated with outside thread, and connecting tube one screws by screw thread with accelerating tube, and guide holder is compressed and location.
5. according to claim 1 or 2 or 3 described Venturi tube-type spreader low resistance force counter flow stops, it is characterized in that: described accelerating tube comprises leading portion, back segment and stage casing, the undergauge section that described stage casing is, and the cone angle of described leading portion is 60 °, the cone angle of back segment is 20 °.
6. according to claim 1 or 2 or 3 described Venturi tube-type spreader low resistance force counter flow stops, it is characterized in that: have two elongated slots under described hydathode on the cylindrical wall of valve body, as the weep hole of discharge recirculation water; Described valve rod three is by the adjusting nut pilot hole and the guiding of the pilot hole on transverse partition that are arranged on lower valve body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320334806 CN203348645U (en) | 2013-06-09 | 2013-06-09 | Venturi tube type low-resistance backflow prevention device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320334806 CN203348645U (en) | 2013-06-09 | 2013-06-09 | Venturi tube type low-resistance backflow prevention device |
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| Publication Number | Publication Date |
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| CN203348645U true CN203348645U (en) | 2013-12-18 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201320334806 Withdrawn - After Issue CN203348645U (en) | 2013-06-09 | 2013-06-09 | Venturi tube type low-resistance backflow prevention device |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103411004A (en) * | 2013-06-09 | 2013-11-27 | 杭州春江阀门有限公司 | Venturi tube type low-resistance backflow preventing device |
| CN107304847A (en) * | 2016-04-18 | 2017-10-31 | 迈克尔·安东尼·迪蒙特 | Equipment to allow or prevent air-flow to enter in enclosed environment or pipe-line system |
| IT201600079436A1 (en) * | 2016-07-28 | 2018-01-28 | Watts Ind Italia Srl | Balancing valve for the regulation of fluid distribution in multiple ducts |
| CN110878856A (en) * | 2019-12-20 | 2020-03-13 | 福建泉牌阀门科技股份有限公司 | Backflow preventer device capable of adjusting seat-back positive pressure difference and flow resistance and working method thereof |
-
2013
- 2013-06-09 CN CN 201320334806 patent/CN203348645U/en not_active Withdrawn - After Issue
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103411004A (en) * | 2013-06-09 | 2013-11-27 | 杭州春江阀门有限公司 | Venturi tube type low-resistance backflow preventing device |
| CN103411004B (en) * | 2013-06-09 | 2015-11-18 | 杭州春江阀门有限公司 | Venturi tube-type spreader low resistance force counter flow stop |
| CN107304847A (en) * | 2016-04-18 | 2017-10-31 | 迈克尔·安东尼·迪蒙特 | Equipment to allow or prevent air-flow to enter in enclosed environment or pipe-line system |
| IT201600079436A1 (en) * | 2016-07-28 | 2018-01-28 | Watts Ind Italia Srl | Balancing valve for the regulation of fluid distribution in multiple ducts |
| EP3276311A1 (en) * | 2016-07-28 | 2018-01-31 | WATTS INDUSTRIES ITALIA S.r.l. | Balancing valve for adjusting the distribution of fluids in multiple pipes |
| US10247590B2 (en) | 2016-07-28 | 2019-04-02 | Watts Industries Italia S.R.L. | Balancing valve for adjusting the distribution of fluids in multiple pipes |
| CN110878856A (en) * | 2019-12-20 | 2020-03-13 | 福建泉牌阀门科技股份有限公司 | Backflow preventer device capable of adjusting seat-back positive pressure difference and flow resistance and working method thereof |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20131218 Effective date of abandoning: 20151118 |
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| C25 | Abandonment of patent right or utility model to avoid double patenting |