Gas safety cut-off valve
Technical field
The present invention relates to the gas valve technical field, exactly relate to a kind of gas safety cut-off valve.
Background technique
As everyone knows, because the distinctive physicochemical property of combustion gas (comprising natural gas, artificial coal gas and liquefied petroleum gas (LPG)) is easy to cause poisoning, blast and fire during leakage, caused great harm and loss for people's lives and properties.More traditional reduction valve has only the effect of decompression, pressure regulation, does not have the function of recloser, and each break-make source of the gas all will be operated artificially.In a single day because people's forgetful property and idea of leaving things to chance are not often in time closed source of the gas after use, will stay hidden danger to safety like this, and gas leakage occurs, just very easily cause various gas accidentses, lack safety guarantee.Renewal along with technology, the valve that has occurred the emergency cut-off fuel gas transportation pipeline on the market, such valve takes place or during because of the need of work throttle down when gas accidents, adopt electromagnetism to cut off the instantaneous energising of coil of controller, the moving iron core of controlling the valve rod assembly whereabouts this moment withdraws from the position-limited lever draw-in groove under magnetic force, position-limited lever withdraws from the valve rod draw-in groove under the main spring effect simultaneously, thereby driving the valve disc assembly falls, valve closing also is in self-locking state, remove power supply this moment, valve is self-locking still, can not reopen.Upwards lift the handle valve disc that resets valve open to the position-limited lever that makes progress and snap under the effect of limit spring in the valve rod draw-in groove when needing manual reset, moving iron core snaps into the position-limited lever draw-in groove under the effect of moving iron core spring, need not electricity consumption and keeps the valve normally open.This valve removes control electricity consumption when cutting off, and other times are consumed power not, and application simple to operate is wider, but this valve for the bigger middle pressure pipe road of discharge pressure owing to cut off the big hand reset difficulty of pressure on the valve disc of back.
A kind of prior art more approaching with the present invention is as follows: notice of authorization number is CN2101914U, notice of authorization day is that the Chinese patent literature on April 15th, 1992 discloses a kind of flammable gas alarm can be blocked source of the gas automatically when combustible gas leakage device that is equipped with, by rotary valve, valve body, spring, lever, compositions such as relay, it is characterized in that: rotary valve, there is through hole to link to each other in the middle of the valve body, cooperate through the conical surface that grinds, rotary valve can rotate with respect to valve body, the rotary valve bottom is with stage clip, top is with torsion spring, torsion spring one end is fixed on the handwheel of rotary valve, the other end is fixed on the positioning screwn, valve body has positioning screwn, penetrate in the curve bath of rotary valve handwheel part, lever is enclosed within the rotating shaft of lever support, and a torsion spring is arranged, (depression of handwheel part interlocks to make lever one end and rotary valve, the other end of lever links to each other with the moving plate of relay, and lever support, relay are fixed on the valve body; Rotary valve is interlocked by lever during normal state, keep normal air feed state, when combustible gas leakage arrives finite concentration, flammable gas alarm output electrical signal engage relay, lever and rotary valve are threaded off, and rotary valve is half-twist under the torsion spring effect, thereby has blocked the passage of source of the gas, having overcome the defective that alarm is only reported to the police, leaking source continues gas leakage, is a kind of practical and effective safety installations.(in addition this safety cut-off valve is as a kind of safety protection device that guarantees pressure governor and combustion gas user security, and when the gas pressure of monitoring place was higher than the cut-out pressure of corresponding setting, safety cut-off valve moved the cut-out air-flow rapidly, and the accident that prevents takes place.Such safety cut-off valve is made up of parts such as supervisory device, shutdown mechanism, valve head stroke display device, resetting means and final controlling element.Under the cut-off valve normal operation, pressure on the monitoring film reaches more accurate balance to the pressure of downstream monitoring place gas at pressure on the monitoring film and predefined spring action by the signal tube feedback effect, lever in final controlling element and the shutdown mechanism keeps buckling, and valve head is in the complete opening state always.When causing that by equipment failure or other reason gas downstream pressure raises, acting on pressure and the spring force imbalance of monitoring on the film will drive lance and move axially the shake-up shutdown mechanism to the right, lever and positive stop hook are thrown off, and valve head cuts off air-flow rapidly under the effect of main spring simultaneously.) but there is defective in above-mentioned traditional lever dropout type structural safety cut-off valve:
1. the final controlling element of traditional lever dropout type structural safety cut-off valve and the lever of shutdown mechanism keep buckling, main valve is opened, employing be mechanical hanger type, cause the positive stop hook wearing and tearing after of long duration, make the stability and the precision of main valve complete opening produce variation, and working life is not long yet.
2. after the conventional security cut-off valve was threaded off, valve head was at the main spring effect incision stream of dying, because spring force is very big, valve head and valve seat clash to the sealing surface damage, and noise is big.
3. resetting of conventional security cut-off valve opened and must positive stop hook and lever be buckled with special tool, and owing to mechanical wear, worker's difficulty that resets is not noted slightly and can't be buckled; Valve head falls the bump valve seat can send very big noise, influences operator's physical and mental health.
Summary of the invention
For solving the problems of the technologies described above, the present invention proposes a kind of reliability height, long service life, noise is little, after the simple gas safety cut-off valve that resets, over-pressure gas medium of the present invention entered the control air chamber, main valve control air chamber pressure increased, overcome the spring thrust that makes progress, spool is moved down be adjacent to valve seat, cut off air-flow rapidly, reach " superpressure is promptly closed ", the effect of sealing zero leakage, reliability and working life improve greatly.
The present invention is achieved through the following technical solutions:
A kind of gas safety cut-off valve comprises main valve and controller, and described main valve comprises valve body, valve seat, spool, valve rod, valve pocket, spring, film pad and elastomer diaphragm.Elastomer diaphragm is a driving mechanism, and valve rod, spool and valve seat are actuator, and described controller is a pneumatic controller, it is characterized in that:
The cylinder step place of a, described valve pocket inner chamber cooperates with the cylinder step place of valve core outer surface, valve pocket upper-end surface and film pad cooperation place and valve pocket inner chamber and valve rod external diameter cooperation place are respectively arranged with O shape circle, the diameter of that less end is consistent in valve base cavity diameter and the described cylinder step place, and described valve rod center is provided with when main valve is worked spool upper and lower end face and overstocks difference for valve rod area and the product of regulating pressure and be in the equalizing orifice of state of equilibrium;
B, described film pad are the disk of butterfly, the middle part perforate of film pad, and diaphragm places on the film pad, and the bonnet of diaphragm and valve body forms airtight control air chamber, and at the spring that is with on the valve rod between valve pocket and diaphragm, spring thrust often leaves main valve;
Connect mutually through PRESSURE PIPE between main valve and the controller, whether the gas medium that is entered by the outside enters described control air chamber via PRESSURE PIPE through described pneumatic controller control and decision, airtight control air chamber keeps former pressure or boosts, diaphragm and valve rod are kept intact or are moved downward the described spring of compression, and spool are held open or closed condition immediately.
Described pneumatic controller comprises second valve body, second spool, piston axostylus axostyle, middle valve cap, second bonnet, second spring, suction valve and petcock, and described petcock communicates with described control air chamber, and suction valve is provided with through hole and communicates with main valve upper film chamber.The sealing area of described second spool is greater than the sectional area of piston axostylus axostyle, and the setting power of second spring equals the sealing area of second spool and the product of pressure medium, piston upper chamber, and the piston upper chamber lifting surface area equals the sectional area that piston area deducts axostylus axostyle.
Described spring is a Returnning spring, and described second spring is a Regulation spring.
The valve body lower end of main valve is sealed by lower cover, and the upper end of valve body connects bonnet.
Described pneumatic controller also comprises the end cap that is connected with described second bonnet and the adjusting screw rod in the described end cap, and the bottom of described adjusting screw rod contacts with described second spring.
Compare with the prior art that with notice of authorization number is the Chinese patent literature representative of CN2101914U with traditional lever dropout type structural safety cut-off valve, advantage of the present invention shows:
1, in the prior art, the final controlling element of tradition lever dropout type structural safety cut-off valve and the lever of shutdown mechanism keep buckling, main valve is opened, what adopt is mechanical hanger type, cause the positive stop hook wearing and tearing after of long duration, make the stability and the precision of main valve complete opening produce variation, and working life is not long yet.And after gas medium of the present invention entered the control air chamber, main valve control air chamber pressure increased, and overcame the spring thrust that makes progress, spool is moved down be adjacent to valve seat, cut off air-flow rapidly, reach " superpressure is promptly closed ", the effect of sealing zero leakage, reliability and working life improve greatly.
2, in the prior art, after the conventional security cut-off valve was threaded off, valve head was at the main spring effect incision stream of dying, because spring force is very big, valve head and valve seat clash to the sealing surface damage, and noise is big; The air pressure of main valve control air chamber of the present invention increases gradually, and the action of the downward throttle down of spool also is very mild, and noise is little, the sealing surface long service life.
3, in the prior art, resetting of conventional security cut-off valve opened and must positive stop hook and lever be buckled with special tool is manual, owing to the reason of mechanical wear, the hand-reset difficulty, do not notice slightly and can't buckle that valve head falls the bump valve seat can send very big noise, influences operator's physical and mental health.And the present invention resets to open and only need close the suction valve handle, opens the petcock handle, can recover proper functioning, and is simple.
Description of drawings
The present invention is described in further detail below in conjunction with specification drawings and specific embodiments, wherein:
Fig. 1 is a closed condition structural drawing of the present invention
Fig. 2 is an opening state structural drawing of the present invention
Fig. 3 is the structural drawing of controller
Mark among the figure:
1, valve body, 2, valve seat, 3, spool, 4, valve rod, 5, equalizing orifice, 6, spring, 7, valve pocket, 8, the film pad, 9, diaphragm, 10, indicating arm, 11, indicator panel, 12, adjusting screw rod, 13, end cap, 14, second bonnet, 15, second spring, 16, middle valve cap, 17, the piston axostylus axostyle, 18, second spool, 19, second valve body, 20, suction valve, 21, petcock, 22, pressure guide hole, 23, PRESSURE PIPE, 24, control air chamber, 25, air vent, 26, connect the downstream signal source, 27, the gas medium import.
Embodiment
Embodiment 1
The invention discloses a kind of gas safety cut-off valve, comprise main valve and controller, main valve adopts high in and low out, gas medium does not directly wash away sealing surface, described main valve comprises valve body 1, valve seat 2, spool 3, valve rod 4, spring 6, valve pocket 7, film pad 8 and elastomer diaphragm 9, elastomer diaphragm 9 is a driving mechanism, valve rod 4, spool 3 and valve seat 2 are actuator, described controller is a pneumatic controller, pneumatic controller commonly used gets final product, the cylinder step place of described valve pocket 7 inner chambers cooperates with the cylinder step place of spool 3 outer surfaces, and the cylinder step is cylindric, and just an end diameter is big, one end diameter is little, its connecting part has just formed step, and the cylinder type step screw of sale is arranged on the market, and the shape of cylinder stepped ramp type and cylindrical step bolt is basic identical among the present invention.Valve pocket 7 upper-end surfaces and film pad 8 cooperation places and valve pocket 7 inner chambers and valve rod 4 external diameter cooperation places are respectively arranged with O shape circle, the diameter of that less end is consistent in valve seat 2 intracavity diameters and the described cylinder step place, and described valve rod 4 centers are provided with when main valve is worked spool 3 upper and lower end faces and overstock difference for valve rod 4 areas and the product of regulating pressure and be in the equalizing orifice 5 of state of equilibrium; Described film pad 8 is the disk of butterfly, the 8 middle part perforates of film pad, and diaphragm 9 places on the film pad 8, and the bonnet of diaphragm 9 and valve body 1 forms airtight control air chamber 24, and at the spring 6 that is with on the valve rod 4 between valve pocket 7 and diaphragm 9, spring 6 thrusts are often opened main valve; Connect mutually through PRESSURE PIPE 23 between main valve and the controller, whether the gas medium that is entered by the outside enters described control air chamber via PRESSURE PIPE 23 through described pneumatic controller control and decision, airtight control air chamber 24 keeps former pressure or boosts, (pressure was that the difference of diaphragm 9 useful area and valve rod 4 areas multiply by setting pressure and deducts upwards thrust of spring 6 when main valve control air chamber 24 was closed) air chamber diaphragm 9 and valve rod 4 are kept intact or are moved downward and compress described spring 6, and spool 3 are held open or closed condition immediately.
Embodiment 2
As the present invention's one better embodiment, on embodiment 1 basis, described pneumatic controller comprises second valve body 19, second spool 18, piston axostylus axostyle 17, middle valve cap 16, second bonnet 14, second spring 15, suction valve 20 and petcock 21, described petcock 21 communicates with described control air chamber 24, the sealing area of described second spool 18 is greater than the sectional area of piston axostylus axostyle 17, the setting power of second spring 15 equals the sealing area of second spool 18 and the product of pressure medium, and the piston upper chamber lifting surface area equals the sectional area that piston area deducts axostylus axostyle.Described pneumatic controller is designed to labyrinth damping piston structure, hard soft pair of matter sealing is adopted in sealing, and when main valve was opened proper functioning, controller suction valve 20 often is in to be opened, petcock 21 is in normally closed, and second spool 18 is under the spring 6 power effects of second spring 15 all the time closes sealing state.Under the cut-off valve normal operation; second spool 18 is in closed condition; no gas medium enters described control air chamber 24; pressure medium is near 0 value in the control air chamber 24; spool 3 is at pressure medium and spring 6 upwards under the active force; be in opening state always; instantly faint breath body pressure is increased to when setting cut-out pressure; second spool 18 is opened; gas medium enters described control air chamber 24 through PRESSURE PIPE 23; under control air chamber 24 active forces, diaphragm 9 and valve rod 4 drive spools 3 and close the cut-out air-flow rapidly, and control air chamber 24 is by the generation back pressure that communicates with piston axostylus axostyle 17 upper ends of the aperture on the suction valve 20; main valve cuts off back downstream line pressure to be reduced; suction valve 20 cuts out, and main valve control air chamber 24 closing pressures remain unchanged, and close overvoltage safety protection effect.Described spring 6 is a Returnning spring, and second spring 15 is a Regulation spring.Valve body 1 lower end of main valve is sealed by lower cover, and the upper end of valve body 1 connects bonnet.Described pneumatic controller also comprises the end cap 13 that is connected with described second bonnet 14 and the adjusting screw rod 12 in the described end cap 13, and the bottom of described adjusting screw rod 12 contacts with described second spring 15.
Working principle of the present invention is as follows:
As shown in Figure 1, under the normal operation of the present invention, the pressure P of downstream monitoring place gas
2Be lower than spring 6 power that preestablish second spring 15 by the pressure of signal tube feedback effect on second spool 18, controller is in closes sealing state, no gas enters in the control air chamber 24 of main valve, control air chamber 24 pressure mediums are near 0 value, valve core of main valve 3 is in the complete opening state always under pressure medium and Returnning spring make progress active force.
As shown in Figure 2, when causing the gas downstream pressure P by equipment failure or other reason
dWhen being increased to the setting cut-out pressure (cut-out pressure is set by adjusting screw rod 12, the adjusting screw rod 12 that turns clockwise, cut-off valve operating pressure setting value increases, otherwise then reduces), P
dAct on pressure on second spool 18 and spring 6 force unbalances on second spring 15, second spool 18 is opened (because second spool, 18 piston areas are much larger than sealing area, sealing area was converted into the piston lifting surface area when second spool 18 started, area increases, rising thrust is big, and controller is accurately opened in very near the setting pressure scope).Gas medium enters the control air chamber 24 of main valve through PRESSURE PIPE 23, and under control air chamber 24 active forces, main valve diaphragm 9 and valve rod 4 drive spools 3 and close the cut-out air-flow rapidly.This moment, main valve indicator panel scale showed closed position.(control air chamber 23 downward active forces equal the gas downstream pressure P
dThe diaphragm 9 useful area S that multiply by control air chamber 24 deduct valve rod 4 area S
BarValve core of main valve 3 is provided with equalizing orifice 5, and upwards active force equals pressure medium P
dMultiply by valve rod 4 area S
BarAdd upper spring 6 power F
BulletThen, valve core of main valve 3 closing pressures equal P
d(S-S
Bar)-(P
dS
Bar+ F
Bullet) 〉=0 is because S is far longer than S
Bar, valve core of main valve 3 moves down rapidly and is adjacent to valve seat 2, closes the cut-out medium.Control air chamber 24 is by the pressure guide hole on the suction valve 20 22 generation back pressure that communicates with piston axostylus axostyle 17 upper ends, main valve cuts off back downstream line pressure to be reduced, suction valve 20 cuts out, main valve control air chamber 24 closing pressures remain unchanged, really realized safety cut-off valve " superpressure is promptly closed ", the sealing zero leakage, long service life.Are better than lever dropout type mechanical structure in sealing reliability and working life.)
When equipment failure is got rid of, the present invention need reset when recovering proper functioning, close suction valve 20 handles, slowly open petcock 21 handles, outfall communicates with main valve control air chamber 24, the gas of emission control air chamber 24, air chamber pressure medium are discharged into when very low, act on the medium power P on the valve core of main valve 3
dS
BarWith spring 6 power F
Bullet, promoting spool 3 upwards, main valve open returns to normal working again.This moment, the main valve indicator panel rose, and scale is in the enable possition.Meanwhile, the gas part of main valve control air chamber 24 makes piston produce area pressure reduction disequilibrium in two ends up and down by the epicoele of the 22 inflow controller pistons of the pressure guide hole in the controller outlet, and under than little spring 6 power effects, second spool 18 is closed sealing.So far whole reseting procedure finishes, and the present invention recovers proper functioning again.
The invention is not restricted to the foregoing description, according to the description of the foregoing description, those of ordinary skill in the art also can make some conspicuous changes, but these changes all should fall within the protection domain of claim of the present invention.