CN206159637U - High -speed admission valve that exhausts of anti -icing anti -water hammer of freezing combined type - Google Patents

Abstract

The utility model discloses a high -speed admission valve that exhausts of anti -icing anti -water hammer of freezing combined type has valve body, valve gap, floater, floater cover, the cover that goes up and down, and the exhaust hood, its characterized in that is equipped with the great annular air chamber of capacity in discharge valve's periphery, thus the water hammer impact wave propagation who produces when low reaches to the valve in the time, because of the air be the elastomer, compressed and absorbing easily to the impact of water hammer has been eliminated, in addition, the annular chamber is equivalent to a thermal insulating layer, can effectively prevent inner chamber silk waste ice. The utility model discloses still taked the multinomial icy measure that prevents or eliminate, can guarantee the exhaust hole and work reliably and effectively prevent the action because of the influence lift cover that freezes.

Description

Anti-freezing water hammer-resistant combined high-speed is vented intake valve

Technical field

The utility model is related to a kind of intake and exhaust valve, more particularly to the exhaust air inlet of Anti-freezing water hammer-resistant combined high-speed Valve.

Background technology

In order to improve emptying effectiveness and prevent aqueduct to be damaged because of negative pressure, combined high-speed exhaust intake valve （Hereinafter referred to as air bleeding valve）It is widely used on water-supply-pipe road.Its major function is：During first water supply, carried out by big steam vent Rapid, high volume is vented, after Quick air-discharge, big vent closure；During normal water supply, the air contained in water accumulates to air bleeding valve top Portion, with being raised and lowered for air pressure, is vented repeatedly by small de-air hole；When occurring negative pressure in aqueduct, for example, have a power failure Or maintenance, when cutting off the water, big steam vent is opened rapidly, and outside air Jing air bleeding valves enter pipeline, negative pressure in pipe is eliminated. CN200420103028X patents disclose a kind of at present using air bleeding valve that is commonplace, being classified as typical construction by GB, but Jing is remained in following deficiency using confirmation, this air bleeding valve：1）Due to substantially full water in lower valve in working order, therefore Water hammer-resistant ability, when stop valve quick closedown after valve or big steam vent quick closedown of supplying water first produce water hammer, easily makes Into the weaker damage parts of ball float equal strength；In addition can not use in severe cold area, otherwise expand because water-ice freezes, cause valve body etc. Part ruptures；2）In the water of conveying unavoidably carry trace impurity, using with the passing of time accumulating in unavoidably in valve, cause air bleeding valve leak or Small de-air hole is blocked, and regular dismounting cleaning is again cumbersome, time-consuming to take a lot of work.

The content of the invention

The utility model mainly solves the deficiency existing for prior art, can prevent frost, can disappear so as to develop one kind Except the combined high-speed of impact of water hammer is vented intake valve.

What above-mentioned technical problem of the present utility model was mainly addressed by following technical proposals：A kind of Anti-freezing is prevented Water hammer combined high-speed is vented intake valve, with valve body, valve gap, ball float, ball float cover, lifting cover, hood, it is characterised in that： Spacer is provided between valve body and ball float cover, the larger closed annular of the capacity of air bleeding valve periphery is formed between spacer cylinder and valve body Air chamber；The bonnet central is provided with big steam vent, and there are upper and lower two circular pits of large and small diameter bottom surface, and has some Radial direction drain tank；Hood middle part is provided with impurity discharging mechanism with the connecting portion of lifting cover, and accumulation can be easily removed at any time Dirt in air bleeding valve.

The technical solution of the utility model can also be further perfect：

Preferably, valve body is lower end there is flange, middle part to have the hollow valve casing of cylinder, the diameter ratio of lower end water inlet The diameter of cylinder is little, and the flange of lower end is typically connected with bolt with the upper flange of service valve, on the lower flange and pipeline of service valve Flange connection, connect heel row air valve perpendicularity should control within 2 °.When air bleeding valve is overhauled, service valve is closed, with The water exempted from pipeline sprays；Several circumferentially uniform screw bolts of valve body upper surface and packing ring one by valve body, hood, Several sleeves, valve gap, sealing gasket, spacer, ball float cover are fastened together, and O-ring seals leak to prevent medium.

Preferably, hood splashes to the water for preventing from being sprayed from big steam vent to surrounding, and prevent dirt from entering row Air valve, is similar to the plate of a back-off, and external diameter is bigger than the external diameter of valve gap；Outer rim surrounding is drilled with several installing holes, quantity, size It is consistent with the screw of the upper surface of valve body 1 with being distributed；Middle part is welded with tapped swivel nut；Band is combined with the internal thread of swivel nut There is the push rod of centre bore, at ordinary times push rod is adjusted to into extreme higher position；The upper end of push rod is connected with handwheel.

Preferably, spacer is a lower end has inlet opening, upper end has the hollow and thin-walled cylinder of flange, is clamped at Between the upper pit of valve gap and the upper surface of valve body；The flange outer diameter of upper end and the big pit external diameter slide fit of valve gap bottom surface；Cylinder The external diameter of top and the upper through hole slide fit of valve body, and it is machined with the groove for installing O-ring seals；The through-hole diameter of upper end is than in it Chamber diameter is little, and there are upper and lower two annular grooves the upper end of through hole.According to use requirement, spacer material can be metal or other Low resin of heat-barrier material, such as heat transfer coefficient etc.；The inwall of the cylindrical and valve body cylinder of spacer cylinder forms annular air chamber, To form closed, resilient, insulation air layer.

Preferably, ball float cover is a upper end has bottom thin cylinder with minor face flange, upper flange is arranged on spacer In the low groove of upper end, the through hole slide fit of the cylindrical top of cylinder and spacer upper end, and it is clamped at the recessed of sealing gasket and spacer Between groove；Cylinder bottom is in spherical crown shape, the cushion pad with water inlet aperture is provided with the hole of bottom center, to when ball float hurtles down It is against damages；The wall of cylinder top surrounding is provided with several uniform louver(-vre)s, between the outer wall of cylinder and the inwall of spacer Form annular chamber.

Preferably, ball float is a upper and lower end carries spherical crown, the cylinder with stainless steel casing, proportion compares water It is little（Typically take 0.7-0.8）；Top is fixed with taper bolt, and the center line of taper bolt is consistent with the center line of ball float；Ball float is dynamic to match somebody with somebody In the endoporus of ball float cover, the gap of the two can ensure that its install perpendicularity be 3 ° when, ball float can be in the endoporus of ball float cover on Under move freely.

Preferably, lifting cover is arranged on ball float top, by slightly arc seal closure and welding wherein in heart hole and Perpendicular guide post group is into guide post is moved in the endoporus of the push rod for fitting over hood center, can freely up and down be moved wherein It is dynamic；Lower end has the taper of the taper bolt on radial hole and axial taper hole, axial taper hole and ball float top completely the same, and the two is close to match somebody with somebody After moisture therein can all be extruded, leak or gas leakage can't occur；The upper end of guide post is combined with nuts and washers, uses To control the extreme lower position that lifting cover falls.Guide post must assure that lifting cover in extreme lower position with the relative position of seal closure When, the outer rim of seal closure is in the following slightly downward position of exhausting window, in order to avoid affect exhaust.

Preferably, sealing gasket is a flat annulus, be arranged on valve gap bottom surface small rut and spacer upper end it is upper In groove, and it is clamped at therebetween, the diameter of centre bore is equal to the diameter of big steam vent, the gradient and lifting cover of lower cone hole Seal closure gradient it is identical, the valve port of the two big steam vent of composition.Sealing gasket is made up of hard rubber elastomeric material.

The utility model beneficial effect is：

1）The larger annular air chamber of capacity is provided with the periphery of air bleeding valve, in the case of normal water supply, even if filling in valve Water is expired, air has been also filled with air chamber, will not have been captured by water, so when the impact of water hammer ripple that downstream produces is delivered in valve When, because air is elastomer, easily absorbed by compression, so as to eliminate the impact of water hammer；Additionally, using in severe cold area When, because the annular air layer of periphery is equivalent to heat insulation layer, inner chamber water freezing can be effectively prevented, during special severe cold, even if The water freezing of inner chamber, because air is easily compressed, also will not rupture the parts such as valve body because water-ice freezes expansion；

2）Take the multinomial measure for preventing or eliminating frost：For example, under the operating mode that normal water supply small de-air hole is closed, Water in small de-air hole is all extruded；And for example, when being vented from large and small steam vent, a small amount of water always is carried over, the water taken out of Can be discharged by several drain tanks below valve gap, make to accumulate in the ponding pole that big steam vent is connected in pit with lifting cover It is little, and soon evaporated, therefore the two can be effectively prevented because of frost " consolidation ", affect the action of lifting cover；For another example, ten thousand " consolidation " is frozen both one, the push rod in the middle part of hood can be depressed, crush frost；

3）Pollution discharge mechanism is provided with, the dirt accumulated in air bleeding valve can be easily removed at any time.

Description of the drawings

Accompanying drawing 1 is a kind of structural representation of the present utility model（State when anhydrous in valve）；

Accompanying drawing 2 is the exhaust done state of Fig. 1.

Description of reference numerals：1st, valve body, 2, crash pad, 3, ball float, 4, ball float cover, 5, taper bolt, 6, spacer, 7, lifting Cover, 8, O-ring seals, 9, sealing gasket, 10, valve gap, 11, sleeve, 12, hood, 13, bolt, 14, packing ring one, 15, handwheel, 16th, push rod, 17, nut, 18, packing ring two, 19, muff；

H1, annular air chamber, H2, annular chamber, H3, discharge chamber；

A, water inlet, b, inlet opening, c, water inlet aperture, d, exhausting window, e, big steam vent, f, radial hole, g, axle To taper hole, h, radial direction drain tank.

Specific embodiment

Below by embodiment, and accompanying drawing is combined, the technical solution of the utility model is further described in detail.

Embodiment：

As illustrated, the utility model is by valve body 1, crash pad 2, ball float 3, ball float cover 4, taper bolt 5, spacer 6, lifting cover 7th, O-ring seals 8, sealing gasket 9, valve gap 10, sleeve 11, hood 12, bolt 13, packing ring 1, handwheel 15, push rod 16, spiral shell Female 17, the part composition such as packing ring 2 18；In addition to sleeve 11, bolt 13, packing ring 1, other each parts are located at after mounting same On center line.

Valve body 1 is that there is flange, middle part to have the hollow valve casing of cylinder for lower end, and the diameter of lower end water inlet a is than cylinder Internal diameter is little, and the flange of lower end is typically with bolt and service valve（It is not drawn in figure）Upper flange connection, the lower flange of service valve with Respective flange connection on pipeline, connecting the perpendicularity of heel row air valve should control within 2 °, when air bleeding valve is overhauled, will to overhaul Valve is closed, in case the water in pipeline sprays；The upper surface of valve body 1 circumferentially uniform 8-12 screw, with bolt 13 and packing ring 1 Valve body 1, hood 12, several sleeves 11, valve gap 10, sealing gasket 9, spacer 6, ball float cover 4 are fastened together, the sealing of O shapes Circle 8 is to prevent medium from leaking.Muff 19 is made up of the low elastomeric material of heat transfer coefficient.

Valve gap 10 is a flat annulus, and center is provided with big steam vent e, and several installations are machined with the end face of outer rim Hole, quantity, size, distribution are consistent with the screw on the upper surface of valve body 1；Bottom surface has upper and lower two annulars of large and small diameter recessed Hole, and have the radial direction drain tank h of 4-6 5 × 5mm of bar.

Spacer 6 is that a lower end has inlet opening b, and upper end has the hollow and thin-walled cylinder of flange, is clamped at valve gap 10 Upper pit and the upper surface of valve body 1 between；The flange outer diameter of upper end and the big pit external diameter slide fit of the bottom surface of valve gap 10；On cylinder The external diameter of side and the upper through hole slide fit of valve body 1, and it is machined with the groove for installing O-ring seals 8；The through-hole diameter of upper end is than in it Chamber diameter is little, and there are upper and lower two annular grooves the upper end of through hole；According to requirements, the material of spacer 6 can be metal or other Low resin of heat-barrier material, such as heat transfer coefficient etc..The inwall of the cylinder of cylindrical and valve body 1 of the cylinder of spacer 6 forms annular air Chamber H1, to form closed, resilient, insulation air layer.

Sealing gasket 9 is a flat annulus, is arranged on the small rut of the bottom surface of valve gap 10 and the upper groove of the upper end of spacer 6 In, and be clamped at therebetween, the diameter of centre bore is equal to the diameter of big steam vent e, gradient and the lifting cover 7 of lower cone hole Seal closure gradient is identical, the valve port of the two big steam vent of composition.Sealing gasket 9 is made up of hard rubber elastomeric material.

Ball float cover 4 is that a upper end has bottom thin cylinder with minor face flange, and upper flange is arranged under the upper end of spacer 6 In groove, the through hole slide fit of the cylindrical top of cylinder and the upper end of spacer 6, and be clamped at sealing gasket 9 and spacer 6 low groove it Between；Cylinder bottom is in spherical crown shape, the cushion pad 2 with water inlet aperture c is provided with the hole of bottom center, to when ball float 3 hurtles down It is against damages；The wall of cylinder top surrounding is provided with 6 uniform louver(-vre) d.Shape between the outer wall of cylinder and the inwall of spacer 6 Circularize chamber H2.

Ball float 3 is that a upper and lower side carries spherical crown, the cylinder with stainless steel casing, and proportion is less than water（Typically take 0.7-0.8）；Top is fixed with taper bolt 5, and the center line of taper bolt 5 is consistent with the center line of ball float 3；Ball float 3 is dynamic to fit over ball float In the endoporus of cover 4, when the gap of the two can ensure that it is 3 ° to install perpendicularity, ball float 3 can be in the endoporus of ball float cover 4 freely up and down It is mobile, it is not crooked not dead.

Hood 12 splashes to the water for preventing from being sprayed from big steam vent e to surrounding, and prevents dirt from entering air bleeding valve, The plate of its one back-off of likeness in form, external diameter is bigger than the external diameter of valve gap 10；Outer rim surrounding is drilled with 4-8 installing hole, quantity, size and Distribution is consistent with the screw of the upper surface of valve body 1；Middle part is welded with tapped swivel nut；It is combined with the internal thread of swivel nut and carries The push rod 16 of centre bore, is adjusted to extreme higher position by push rod 16 at ordinary times；The upper end of push rod 16 is connected with handwheel 15.Hood 12 with Cavity between valve gap 10 is discharge chamber H3.

Lifting cover 7 is arranged on the top of ball float 3, and the seal closure and welding by slightly arc is wherein in heart hole and perpendicular Guide post group into guide post is moved in the endoporus for fitting over push rod 16, can freely up and down be moved wherein；There is radial hole f lower end It is completely the same with the taper of axial taper hole g, axial taper hole g and taper bolt 5, the two is close match somebody with somebody after moisture therein can all be squeezed Go out, leak or gas leakage can't occur；The upper end of guide post is combined with nut 17 and packing ring 18, falls to control lifting cover 7 Extreme lower position.Guide post must assure that lifting cover 7 in extreme lower position with the relative position of seal closure, and the outer rim of seal closure exists The following slightly downward positions of exhausting window d, in order to avoid affect exhaust.

Impurity excludes mechanism：

Contain trace impurity in the water of conveying unavoidably, with the passing of time there must be part to accumulate in valve, to large and small steam vent（Radially Aperture）Have undesirable effect, for example, be embedded on sealing surface and cause to leak or block small de-air hole, it is therefore desirable to periodically carry out clear Reason.Method for cleaning is as follows：Handwheel 15 is rotated, declines push rod 16, until big steam vent e is opened, with the pressure of impurity in valve Power water sprays from big steam vent e；Clean out, anti-phase rotation handwheel 15 must rise to extreme higher position push rod 16.This There is following two functions in mechanism：1）Just in case big steam vent is frozen, can be crushed with method；2）During first water supply sometimes Need to confirm whether be filled with water in pipeline, now, first confirm that the guide post of lifting cover 7, whether in extreme higher position, then drops Lower push-rod 6, opens big steam vent e, if water is discharged, then can confirm to have had been filled with water in pipeline, because air bleeding valve is general Installed in the peak of pipeline.

Operation principle of the present utility model：

When anhydrous in valve（Fig. 1）, ball float 3 is located at the bottom of ball float cover 4, and lifting cover 7 is in extreme lower position, now circular cone Pin 5 is detached with the axial taper hole g of the guide post lower end of lifting cover 7.Again to pipeline confession after first or pipe-line system is overhauled During water, substantial amounts of air Jing service valves, water inlet a, inlet opening b, annular chamber H2, exhausting window d enter ball float cover 4 in pipeline It is interior, subsequently quickly discharged by big steam vent e and discharge chamber H3.Because air bleeding valve is typically mounted at the peak of pipeline, Therefore after the air emptying in pipeline, water is first filled with pipeline, then enters air bleeding valve by water inlet a；Due to annular empty Air cavity H1 be it is open downwards, when it is waterborne be raised to its lower mouth when, annular air chamber H1 becomes a closed air chamber, therefore water Will not enter, so certain thickness annular air layer can be formed with the whole periphery of air bleeding valve；Pass through into the water in valve Inlet opening b rises in annular chamber H2, while water enters the bottom of ball float cover 4 by water inlet aperture c, ball float 3 is in buoyancy Lower rising, taper bolt 5 and conical bore g it is closely sealed after drive lifting cover 7 rise together, until the seal closure of the lower end of lifting cover 7 with Sealing gasket 9 is contacted, and under buoyancy by big steam vent e close, it is water-tight;Moment before closing, the air in annular chamber H2 Also drain, and allow a small amount of water to discharge from big steam vent e, the water of discharge is by the sluicing on the lower surface of valve gap 10 Groove h is discharged；Simultaneously under buoyancy, taper bolt 5 and axial direction taper hole g are tightly pressed together, by the water whole in taper hole g Extrusion, and it is water-tight, air tight；So far Quick air-discharge terminates（Fig. 2）.Terminate when Quick air-discharge, water-filling is completed, large and small（Radially Aperture）After vent closure, the top of ball float 3 remains partial air, and this partial air is closed, and with certain pressure, Therefore in normal water supply, big steam vent e will not be opened.With the change of temperature and pressure in water supply process, in water Air be released, and to the top of ball float 3, the Spatial Agglomeration of the lower section of lifting cover 7, air pressure is constantly raised, in valve under water level Drop, the buoyancy suffered by ball float 3 also decreases, when the weight of ball float 3 exceed suffered buoyancy and conical bore g upper end areas because During upwards thrust sum suffered by inside and outside differential pressure, ball float 3 declines, small de-air hole（Warp-wise aperture）F is opened, having above ball float 3 Body of calming the anger is discharged by axial direction taper hole g and inlet opening c；After body of calming the anger is discharged, water level is raised in valve, and ball float 3 rises, Again will be little（Radial hole）Vent closure, such iterative cycles.Air takes a small amount of water out of unavoidably when discharging from small de-air hole Point, if using traditional structure, water will accumulate in little（Radial hole）In steam vent, severe cold season can cause icing and Blocking is little（Radial hole）Steam vent.The structure that the utility model is adopted is as it was previously stated, the water in small de-air hole can be accumulated in Divide all extrusions, therefore will not occur because of the failure of frost blocking.

When pipe drainage, negative pressure is produced in pipeline, water level declines rapidly in valve, and ball float 3 falls back to the bottom of ball float cover 4 Portion, lifting cover 7 falls back to minimum point, and big steam vent e is opened, and extraneous air is by the order contrary with during exhaust to pipeline Interior tonifying Qi, it is therefore prevented that pipeline is damaged because producing negative pressure.

As described above, because annular air chamber H1 is closed, water will not be entered, and this is equivalent to air bleeding valve by one The thicker annular air layer of layer is surrounded, and it is elastomer, is again heat insulation layer, therefore can absorb the impact of water hammer generation Ripple, and air bleeding valve is made from frost, if used in severe cold area, spacer 6 can adopt the low material of heat transfer coefficient.Additionally, from The water that large and small steam vent is discharged can be discharged by some drain tank h；The water energy being retained in axial taper hole g is complete Portion extrudes, and can so prevent large and small steam vent from freezing, it is ensured that air bleeding valve reliably works.The utility model is used in severe cold Area, can Anti-freezing. and can water hammer-resistant；If used in torrid areas, merely to water hammer-resistant, then in structure slightly Change just.

Claims (8)

1. a kind of Anti-freezing water hammer-resistant combined high-speed is vented intake valve, with valve body（1）, valve gap（10）, ball float（3）, ball float Cover（4）, lifting cover（7）, hood（12）, it is characterised in that：Valve body（1）With ball float cover（4）Between be provided with spacer（6）, spacer （6）Cylinder and valve body（1）Between form the larger closed annular air chamber of capacity of air bleeding valve periphery（H1）；The valve gap （10）Center is provided with big steam vent（e）, there are upper and lower two circular pits of large and small diameter bottom surface, and has some radially to sluice Groove（h）；The ball float（3）The taper bolt at top（5）With lifting cover（7）Guide post lower end axial taper hole（g）Taper it is complete It is complete consistent；The hood（12）Middle part and lifting cover（7）Connecting portion be provided with impurity discharging mechanism.

2. Anti-freezing water hammer-resistant combined high-speed according to claim 1 is vented intake valve, it is characterised in that：Spacer (6) It is that a lower end has inlet opening (b), upper end has the hollow and thin-walled cylinder of flange, is clamped at valve gap（10）Upper pit with Between the upper surface of valve body (1)；The cylinder external diameter and valve body of upper end（1）Upper through hole slide fit, and be machined with installation O-ring seals （8）Groove；The through-hole diameter of upper end is less than its intracavity diameter, and there are upper and lower two annular grooves the upper end of through hole.

3. Anti-freezing water hammer-resistant combined high-speed according to claim 1 and 2 is vented intake valve, it is characterised in that：Ball float Cover（4）It is that a upper end has bottom thin cylinder with minor face flange, upper flange is arranged on spacer（6）In the low groove of upper end, The cylindrical top of cylinder and spacer（6）The through hole slide fit of upper end, and it is clamped at sealing gasket（9）And spacer（6）Low groove between； Cylinder bottom is in spherical crown shape, and band water inlet aperture is provided with the hole of bottom center（c）Cushion pad（2）, in ball float（3）Hurtle down When it is against damages；The wall of cylinder top surrounding is provided with several uniform louver(-vre)s（d）, the outer wall and spacer of cylinder（6）'s Annular chamber is formed between inwall（H2）.

4. Anti-freezing water hammer-resistant combined high-speed according to claim 1 and 2 is vented intake valve, it is characterised in that：Ball float （3）It is cylinder of the upper and lower end with spherical crown, proportion is less than water；Top is fixed with taper bolt（5）, taper bolt（5）In The heart and ball float（3）Center line it is consistent；Ball float（3）It is dynamic to fit over ball float cover（4）Endoporus in, the gap of the two can ensure that its installation Perpendicularity can be in ball float cover when being 3 °（4）Endoporus in freely up and down move.

5. Anti-freezing water hammer-resistant combined high-speed according to claim 1 and 2 is vented intake valve, it is characterised in that：Lifting Cover（7）It is arranged on ball float（3）Top, by the seal closure and welding of slightly arc wherein in heart hole and perpendicular guiding Bar is constituted；Guide post is moved in the endoporus of the push rod (16) for fitting over hood center, can freely up and down be moved wherein；There is footpath lower end Taper to aperture (f) and axial taper hole (g), axial taper hole (g) and taper bolt (5) is completely the same, the two is close match somebody with somebody after can be by Moisture therein is all extruded, and leak or gas leakage can't occur；The upper end of guide post is combined with nut (17) and packing ring (18), To control lifting cover（7）The extreme lower position of whereabouts.

6. Anti-freezing water hammer-resistant combined high-speed according to claim 1 and 2 is vented intake valve, it is characterised in that：Sealing Pad（9）It is a flat annulus, is arranged on valve gap（10）The lower pit of bottom surface and spacer（6）In the upper groove of upper end, and quilt Clamp between, the diameter of centre bore is equal to big steam vent（e）Diameter, the gradient and lifting cover of lower cone hole（7）It is close Sealing cover gradient is identical, the valve port of the two big steam vent (e) of composition.

7. Anti-freezing water hammer-resistant combined high-speed according to claim 1 and 2 is vented intake valve, it is characterised in that：Exhaust Cover（12）The plate of its one back-off of likeness in form, external diameter compares valve gap（10）External diameter it is big；Outer rim surrounding is drilled with several installing holes, number Amount, size and distribution are consistent with the screw of the upper surface of valve body 1；Centre is welded with tapped swivel nut；In the internal thread of swivel nut It is combined with the push rod with centre bore（16）, at ordinary times by push rod（16）It is adjusted to extreme higher position；Push rod（16）Upper end be connected with Handwheel（15）.

8. Anti-freezing water hammer-resistant combined high-speed according to claim 1 and 2 is vented intake valve, it is characterised in that：Valve body Lower section neck outside is provided with muff（19）.