CN201787144U

CN201787144U - Secondary check valve

Info

Publication number: CN201787144U
Application number: CN2010202668912U
Authority: CN
Inventors: 王朝阳; 严品望; 方建土; 吕烈平
Original assignee: NINGBO HUACHENG VALVE CO Ltd
Current assignee: NINGBO HUACHENG VALVE CO Ltd
Priority date: 2010-07-22
Filing date: 2010-07-22
Publication date: 2011-04-06
Anticipated expiration: 2020-07-22

Abstract

The utility model relates to a secondary check valve, comprising a valve body and valve cores, wherein the valve body is provided with a valve seat; the valve cores are movably arranged in the valve body; the valve seat is provided with a water inlet and a water outlet at the two end parts; each valve core comprises a primary valve core arranged at the water inlet and a secondary valve core arranged at the water outlet; the valve body is provided with an exhaust port; when the primary valve core opens the water inlet, the exhaust port is closed, and when the primary valve core closes the water inlet, the exhaust port is opened; and the secondary valve core opens or closes the water outlet by moving relative to the valve seat. In the utility model, the valve body is internally provided with two valve cores, the secondary check valve can effectively prevent backflow when in normal work, even though the sealing performance among the valve cores and the valve seat, the backflow entering from the water outlet is directly discharged from the exhaust port instead of flowing back from the water inlet, and the backflow pollution can be effectively prevented.

Description

A kind of secondary safety check

Technical field

The utility model relates to valve technology field, relates in particular to a kind of secondary safety check.

Background technique

Safety check is widely used in pipe-line system as a kind of unidirectional, reverse stop valve, is mainly used to prevent that fluid from flowing backwards pollutes.Safety check generally includes valve body, valve body is provided with valve seat, spool valve seat relatively moves axially or rotates in a circumferential direction, variation by pressure in the pipeline makes the relative valve seat motion of spool, make safety check be in that forward is opened or reverse closed condition, thereby but make the fluid positive flow cross safety check and prevent reverse refluence.For example, the patent No. is that the Chinese utility model patent of ZL200920112116.9 discloses a kind of safety check, this safety check comprises that an inside is the valve body of cavity, be provided with Sealing and locating piece in the valve body, locating piece is connected in the valve body, between locating piece and Sealing, be provided with spring, has a sealing surface that is complementary with Sealing in the valve body, elastic force effect lower seal at spring is resisted against formation sealing on the sealing surface, have the guide rod that is shaft-like on the locating piece, have the guide structure that seal bar is moved along guide rod between Sealing and the guide rod.The sealing difference is the outstanding problem that existing safety check exists, and in a single day the sealing of safety check is damaged, and flows backwards and reveals just inevitable.

Summary of the invention

The purpose of this utility model is to improve the anti-back flow performance of safety check, even when the sealing of safety check is damaged, also can not flow backwards.

In order to realize purpose, the technical solution adopted in the utility model is, a kind of secondary safety check, comprise valve body and spool, valve body has valve seat, spool is arranged in the valve body movably, valve seat has water intake and the water outlet that lays respectively at two end part, spool comprises the one-level spool that is located at water intake and is located at the secondary spool of water outlet, valve body is provided with relief opening, with exhaust close, with Exhaust Open, the secondary spool opens or closes water outlet by moving relative to valve seat when the one-level spool is closed water intake when the one-level spool is opened water intake.

The utility model is provided with two spools in valve body, the secondary safety check can prevent to flow backwards when proper functioning effectively, even when the sealing between spool and valve seat is damaged, the refluence that enters from water outlet directly excretes from relief opening, and can not flow backwards from water intake, can prevent from effectively to flow backwards and pollute.

Description of drawings

Fig. 1 is the utility model secondary safety check sectional view that is in the normal water supply state;

Fig. 2 is the utility model secondary safety check sectional view that is in improper water supply state.

Below in conjunction with accompanying drawing the utility model is described in detail.

Embodiment

Referring to Fig. 1 and Fig. 2, the utility model secondary safety check comprises valve body 1, and valve body 1 is roughly hollow structure, has valve seat 11 in the middle, and is provided with relief opening 14.Valve seat 11 is roughly tubular, the runner that inner formation is passed through for fluid, and have water intake 12 and the water outlet 13 that lays respectively at two end part.

Spool is arranged in the valve body 1 movably, comprises one-level spool that is located at water intake 12 and the secondary spool that is located at water outlet 13.The one-level spool comprises valve rod 1, barrier film 22, pad 1 and spring 1, and it is cylindric that valve rod 1 is substantially, has the boss 211 at front end, and pad 1 is arranged on the rearward end of valve rod 1.The secondary safety check also comprises valve gap 4, valve gap 4 is threaded with the front end of valve body 1, has positioning seat 1 at the middle part, positioning seat one 15 middle parts are provided with through hole, valve rod 1 passes across positioning seat 1 through this through hole, boss 211 and pad 1 lay respectively at the front side and the rear side of positioning seat 1, and spring 1 is arranged between boss 1 and the positioning seat 1.Valve gap 4 is clamped in the outer end of barrier film 22 between valve body 1 and the valve gap 4, thereby the outer end of barrier film 22 is installed on the valve seat 1, and this has made things convenient for the installation of barrier film on the one hand, plays seal action on the other hand between valve body 1 and valve gap 4.The inner of barrier film 22 is between positioning seat 1 and the pad 1, and the front-end face of the ear end face of positioning seat 1 and pad 1 is the plane, and when closing water intake 12, positioning seat 1 and pad 1 can get diaphragm clip tighter, and it is more firm to contact, and sealing is better.Along with the variation in pressure of side before and after the one-level spool, when valve rod 1 moved backward to a certain degree, barrier film 22 was separated from pad 1 and contacts with valve seat 11, at this moment, water intake 12 is opened, and relief opening 14 is closed, water can enter the valve body 1 from water intake 12, and the state of one-level spool as shown in Figure 1; When valve rod 1 moves forward, pad 1 can drive barrier film 22 and move forward, be clamped between positioning seat 1 and the pad 1 until the inner of barrier film 22, at this moment, barrier film 22 is closed water intake 12, and water can not enter valve body 1 from water intake 12, and relief opening 14 is opened, be that relief opening 14 is communicated with water intake 12, the state of one-level spool as shown in Figure 2.

The secondary spool comprises valve rod 2 31, pad 2 33 and spring 2 32, and it is cylindric that valve rod 2 31 also is substantially, has the boss 311 at front end, and pad 2 33 is arranged on the rearward end of valve rod 2 31.Valve body 1 has the positioning seat 2 16 at the middle part, positioning seat 2 16 middle parts are provided with through hole, valve rod 2 31 passes across positioning seat 2 16 through this through hole, and boss 2 311 and pad 2 33 lay respectively at the front side and the rear side of positioning seat 2 16, and spring 2 32 is arranged between boss 2 311 and the positioning seat 2 16.Pad 2 33 is tapered, and the awl end is contacted with water outlet 13 by the conical surface at the rear side of water outlet 13, but the contact and the sealing effect of 2 33 pairs of water outlets of reinforced gasket.Along with the variation in pressure of side before and after the secondary spool, when valve rod 2 31 moved forward to pad 2 33 and connects with water outlet 13, water outlet 13 was closed, and the water in the valve body can not flow out from water outlet, this moment the secondary spool state as shown in Figure 2; When valve rod 2 31 moved backward to pad 2 33 and is separated from water outlet 13, water outlet 13 was opened, and the water in the valve body flows out from water outlet, this moment the secondary spool state as shown in Figure 1.

The secondary safety check also comprises liquor separator 5, and liquor separator 5 has a plurality of through holes (more than three or three, only showing two among the figure) along the circumferencial direction array, and through hole is communicated with relief opening 14, and liquor separator 5 is in the outside of valve seat 11 and be positioned at the inlet end of valve seat 11.When barrier film 22 contact valve seats 11, barrier film 22 also contacts liquor separator 5 simultaneously, has increased the area of contact of barrier film 22, plays the closing function of enhancing to relief opening 14.The secondary safety check also comprises the filter screen 8 that is arranged on one-level spool front side, and filter screen 8 is in valve gap 4, and water or other fluids filter the back in entering valve body through filter screen 8 earlier, and spool is played a protective role.The rear end of the front end of valve gap 4 and valve body 1 is respectively equipped with connecting head 6 and connecting head 7, and the secondary safety check is connected with external pipe with connecting head 7 by connecting head 6.

Below in conjunction with accompanying drawing the working principle of the utility model secondary safety check is carried out simple declaration.Referring to Fig. 1, under the normal water supply situation, the one-level spool is opened water intake 12 simultaneously relief opening 14 is closed, and barrier film 22 contacts with valve seat 11 and is separated from pad 1; The secondary spool is closed water outlet, and pad 2 33 detaches the mouth of a river 13.The water in water-main road enters the valve body 1 from water intake 12, flow out to supply water from water outlet 13 by one-level spool and secondary spool successively to the user, because the liquor separator 5 and the relief opening 14 of barrier film 22 back directly communicate with atmosphere, so there is a very big pressure difference barrier film 22 front and back, barrier film 22 closely contacts with valve seat 11 on the valve body 1, relief opening 14 is water-tight, secondary safety check normal water supply.Pipeline no user behind the secondary safety check under the static situation of water, remains unchanged as preceding loine pressure, exists pressure reduction still to be closed condition before and after the one-level spool.If preceding loine pressure descends, when being lower than the spring force of one-level spool, the one-level spool is closed, and pad one drives the barrier film reach, and barrier film 22 is separated with valve seat 11, and water intake 12 is closed, thereby relief opening 14 is opened the beginning draining.When the sealing of secondary safety check is damaged, the ductwork pressure behind the secondary safety check raises, and surpasses the water intake pressure before the secondary safety check, if the intact nothing of the locational secondary seal spool of water outlet is leaked, high pressure water can not flow backwards; If the locational secondary seal spool of water outlet goes to pot, the pressure of the locational secondary spool of water outlet front side raises, and the front and back pressure reduction of one-level spool is during less than the spring force of one-level spool, and the one-level spool is closed, barrier film 22 breaks away from valve seat 11, and relief opening 14 is opened draining.If the one-level spool on the water inlet position suffers seal break-off simultaneously, because the high pressure water that flows backwards back from water outlet is from the relief opening pressure release, so can be from the water intake preceding pipeline that not flow backwards back.When current loine pressure dropped to zero or negative pressure, the one-level spool was closed, and barrier film and valve seat break away from, and relief opening is opened draining fully, and air enters vacuum chamber from relief opening, thereby prevents to produce siphon refluence phenomenon.

The utility model secondary safety check is a kind of of backflow preventer, is mainly used to prevent in the water transfer pipe network owing to the refluence that back pressure or backsiphonage produce is polluted; It is exclusively used in small-bore supply line, is that the useful of decompression type backflow preventer replenished.It is specially adapted to laboratory equipment, operation jar, sterilizer, dairy equipment and small household appliance; Also can be used for boiler water inlet pipe, the backflow that is produced to prevent when supply pressure is lower than system pressure; It also can be used in hot water or the chilled water system.

The foregoing description only is used for the understanding to the utility model design; be not to restriction of the present utility model; design can also have the variation of many structures according to the utility model; for example; valve gap can be one-body molded with valve body; positioning seat one also can be arranged on the valve body, and these structural simple change all belong to protection domain of the present utility model.

Claims

1. secondary safety check, comprise valve body (1) and spool, described valve body (1) has valve seat (11), described spool is arranged in the described valve body (1) movably, described valve seat (11) has water intake (12) and the water outlet (13) that lays respectively at two end part, it is characterized in that, described spool comprises the one-level spool that is located at described water intake (12) and is located at the secondary spool of described water outlet (13), valve body (1) is provided with relief opening (14), when the one-level spool when opening is closed water intake (12) with relief opening (14), when the one-level spool when closing is opened water intake (12) with relief opening (14), described secondary spool opens or closes described water outlet (13) by moving relative to valve seat (11).

2. secondary safety check according to claim 1, it is characterized in that, described one-level spool comprises barrier film (22), when described barrier film (22) contacts described valve seat (11), described water intake (12) is opened, when described barrier film (22) broke away from described valve seat (11), described water intake (12) was closed.

3. secondary safety check according to claim 2, it is characterized in that, described secondary safety check is provided with positioning seat one (15), described one-level spool also comprises the valve rod one (21) that passes across described positioning seat one (15), described valve rod one (21) is provided with boss one (211) and the pad one (23) that lays respectively at described positioning seat one (15) front side and rear side, between described boss one (211) and positioning seat one (15), spring one (24) is set, the outer end of described barrier film (22) is installed on the described valve seat (1), and the inner of barrier film (22) is between described positioning seat one (15) and the pad one (23).

4. secondary safety check according to claim 3, it is characterized in that, described secondary safety check also comprises liquor separator (5), described liquor separator (5) have be communicated with a plurality of through holes of described relief opening (14) and, described liquor separator (5) is in the outside of described valve seat (11) and be positioned at the inlet end of described valve seat.

5. secondary safety check according to claim 4 is characterized in that, described secondary safety check also comprises the valve gap (4) that connects described valve body (1), and the outer end of described barrier film (22) is clamped between described valve body (1) and the valve gap (4).

6. secondary safety check according to claim 5 is characterized in that, described positioning seat one (15) is arranged on the described valve gap (4).

7. secondary safety check according to claim 6 is characterized in that, described secondary safety check also comprises the filter screen (8) that is arranged on described one-level spool front side.。

8. secondary safety check according to claim 3 is characterized in that, the front-end face of the ear end face of described positioning seat one (15) and described pad one (23) is the plane.

9. secondary safety check according to claim 3, it is characterized in that, described valve seat (1) is provided with positioning seat two (16), described secondary spool comprises the valve rod two (31) that passes across described positioning seat two (16), described valve rod two (31) is provided with boss two (311) and the pad two (33) that lays respectively at described positioning seat two (16) front sides and rear side, between described boss two (311) and positioning seat two (16) spring two (32) is set.

10. secondary safety check according to claim 9 is characterized in that, described pad two (33) is tapered, and the awl end is at the rear side of water outlet (13).