CN205824298U - A kind of nuclear power main steam relief valve - Google Patents

Abstract

This utility model relates to a kind of nuclear power main steam relief valve, including valve body, radiator and Elastic valve core device, valve body includes valve body inlet port, radiator connected entrance end, valve body outlet port, valve body chamber, valve body chamber is provided with valve seat, radiator includes valve body connected entrance end, valve gap connected entrance end, radiator chamber, Elastic valve core device includes feather valve lever apparatus and Valve clack device, Valve clack device includes flap, flap seat, fairlead, it is provided with back pressure cavity between flap seat and valve body connected entrance end, feather valve lever apparatus includes valve rod, spring members, valve gap, flap is pushed against and is pressed on valve seat closure valve body air intake end by one end of valve rod, valve rod is provided with discharge chamber with gusset in valve body connected entrance end, it is arranged with adjusting nut in the part that valve rod is corresponding with discharge chamber, spring members includes lower spring cup, spring, upper spring seat.This utility model uses unique back pressure cavity and discharge chamber design to carry out the blowdown of a safety valve of control valve, improves the work efficiency of steam security valve.

Description

A kind of nuclear power main steam relief valve

Technical field

This utility model relates to a kind of relief valve, particularly to a kind of nuclear power main steam relief valve, belongs to relief valve field.

Background technology

Relief valve is the valving that spool is in normally off, the medium pressure in the equipment using relief valve or pipeline When power increases to over setting value, automatically turn on outside system discharge medium and exceed setting to pressure medium in preventing pipeline or equipment The Special valve of numerical value.Relief valve belongs to automatic valve class, is used primarily on boiler, pressure vessels and pipes, plays control pipeline Interior pressure is less than the effect of setting value, thus guarantees personal safety and equipment is properly functioning.Existing steam security valve one As be provided with fairlead adjusting ring and valve seat adjusting ring (upper and lower adjusting ring) regulating measure as performance indications, regulating measure has Limit, fairlead adjusting ring and valve seat adjusting ring use standard thread to connect, and the most easily kill and turn motionless.Nuclear power main steam Relief valve, for providing the overpressure protection of nuclear power station steam generator and main steam pipe, concurrently facilitates by discharging reactor The energy that coolant system produces prevents primary Ioops side superpressure and the overheated and quantity by restriction steam release and speed Prevent reactor core supercool.Compared with nuclear power main steam relief valve, conventional steam security valve does not has antiseismic test requirements document, does not has yet There is minimum natural frequency requirement.

Summary of the invention

This utility model nuclear power main steam relief valve discloses new scheme, uses unique back pressure cavity and discharge chamber design Carry out the blowdown of a safety valve of control valve, solve the problem that existing steam security valve regulating measure is limited.

This utility model nuclear power main steam relief valve includes valve body, radiator and Elastic valve core device, and valve body includes being located at The valve body inlet port of valve body lower portion, it is located at the radiator connected entrance end on valve body top, is located at the valve body gas outlet of valve body-side End, the valve body chamber of valve inner, be provided with valve seat with valve body inlet port connectivity part bottom valve body chamber, and radiator includes being located at heat radiation The valve body connected entrance end of device bottom, being located at the radiator chamber within the valve gap connected entrance end on radiator top, radiator, valve body is even Port end is fixing with radiator connected entrance end to be connected, and Elastic valve core device includes feather valve lever apparatus and is located at the endoceliac valve of valve Lobe device, Valve clack device includes flap, flap seat, fairlead, and flap is slidably located in by the flap seat being pressed on flap In fairlead, the upper end of fairlead connects, with valve body connected entrance end, the back pressure being formed between flap seat and valve body connected entrance end Chamber, feather valve lever apparatus includes valve rod, the spring members being set on valve rod, the valve gap that is located at outside spring members, valve gap with The fixing connection of valve gap connected entrance end, flap is pushed against through flap seat and is pressed on valve seat closure valve body air intake by one end of valve rod End, the other end of valve rod sequentially passes through after valve body connected entrance end, valve gap connected entrance end bottom pass-out valve gap, through radiator chamber Valve rod is provided with, with gusset in valve body connected entrance end, the discharge chamber set along valve rod circumference ring, and the part that valve rod is corresponding with discharge chamber is overlapped Being provided with adjusting nut, adjusting nut forms slipper seal with discharge chamber and is connected, and discharge chamber produces by sliding with adjusting nut Gap connects with back pressure cavity, and discharge chamber passes through the external aerofluxus of vent connection, and spring members includes the lower spring being fixed on valve rod Seat, the spring being set on valve rod, being fixed on upper spring seat valve gap within, the valve rod other end passes pass-out valve after upper spring seat Bottom lid, one end of spring is fixing with lower spring cup to be connected, and the other end of spring is fixing with upper spring seat to be connected.

High steam is by flap upwards jack-up, and adjusting nut moves upward with valve rod and produces gap, back pressure between discharge chamber Steam in chamber enters along above-mentioned gap by vent connection discharge valve after discharge chamber, valve rod under the effect of spring assembly with In pipeline, the decline of steam pressure drives downwards adjusting nut gradually to block above-mentioned gap, and back pressure cavity internal gas pressure gos up, and flap seals Stifled valve body inlet port.

This utility model nuclear power main steam relief valve uses unique back pressure cavity and discharge chamber design to carry out opening of control valve Close pressure reduction, improve the work efficiency of steam security valve.

Accompanying drawing explanation

Fig. 1 is the cross-sectional schematic of a kind of embodiment of this utility model nuclear power main steam relief valve.

Fig. 2 is the close-up schematic view in Fig. 1 at fairlead.

Fig. 3 is the close-up schematic view in Fig. 1 at locating ring.

Fig. 4 is the close-up schematic view in Fig. 1 at lining.

Fig. 5 is the close-up schematic view at back pressure cavity in Fig. 1, discharge chamber.

Wherein, 1.1 is valve body, and 1.2 is valve seat, and 2 is lower adjusting ring, and 3 is flap, and 4 is lower adjusting ring support pin, and 5 is to raise Pitch circle support pin, 6 is upper adjusting ring, and 7 is flap seat, and 8 is fairlead, and 9 is flap nut, and 10 is radiator, and 14 is adjusting nut, 15 is locating ring, and 17 is valve rod, and 18 is lower spring cup, and 19 is spring, and 20 is valve gap, and 21 is upper spring seat, and 22 is thrust bearing, 23 is that thrust bearing connects seat, and 24 is to adjust screw rod, and 25 is lining, and 26 is locking nut, and 27 is protective cover, and 28 is limited bolt, 30 is vent connection, and A is discharge chamber, and B is back pressure cavity.

Detailed description of the invention

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

As it is shown in figure 1, the schematic diagram of this utility model nuclear power main steam relief valve.Nuclear power main steam relief valve includes valve Body, radiator and Elastic valve core device, valve body includes being located at the valve body inlet port of valve body lower portion, being located at the heat radiation on valve body top Device connected entrance end, it is located at the valve body chamber of the valve body outlet port of valve body-side, valve inner, with valve body air inlet bottom valve body chamber End connectivity part is provided with valve seat, and radiator includes being located at the valve body connected entrance end of bottom radiator, being located at the valve gap on radiator top Radiator chamber within connected entrance end, radiator, valve body connected entrance end is fixing with radiator connected entrance end to be connected, and Elastic valve core fills Putting and include feather valve lever apparatus and be located at the endoceliac Valve clack device of valve, Valve clack device includes flap, flap seat, fairlead, valve Lobe is slidably located in fairlead by the flap seat being pressed on flap, and the upper end of fairlead connects shape with valve body connected entrance end Becoming the back pressure cavity between flap seat and valve body connected entrance end, feather valve lever apparatus includes valve rod, the spring being set on valve rod Parts, the valve gap being located at outside spring members, valve gap is fixing with valve gap connected entrance end to be connected, and one end of valve rod will through flap seat Flap pushes against and is pressed on valve seat closure valve body air intake end, and the other end of valve rod sequentially passes through valve body connected entrance end, valve gap even After port end bottom pass-out valve gap, it is provided with gusset in valve body connected entrance end through the valve rod in radiator chamber and sets along valve rod circumference ring Discharge chamber, the part that valve rod is corresponding with discharge chamber is arranged with adjusting nut, adjusting nut forms slipper seal with discharge chamber Connecting, discharge chamber is connected with back pressure cavity by the gap produced of sliding with adjusting nut, and discharge chamber is externally arranged by vent connection Gas, spring members includes the lower spring cup being fixed on valve rod, the spring being set on valve rod, is fixed on the upper bullet within valve gap Spring abutment, the valve rod other end is through bottom pass-out valve gap after upper spring seat, and one end of spring is fixed with lower spring cup and is connected, spring The other end is fixing with upper spring seat to be connected.Flap upwards jack-up, adjusting nut are moved upward and aerofluxus by high steam with valve rod Producing gap between chamber, the steam in back pressure cavity passes through vent connection discharge valve after entering discharge chamber along above-mentioned gap, and valve rod exists Adjusting nut is driven downwards gradually to block above-mentioned gap, back pressure cavity with the decline of steam pressure in pipeline under the effect of spring assembly Internal gas pressure gos up, flap closure valve body inlet port.As it is shown in figure 5, the back pressure cavity of such scheme has been used in combination with discharge chamber Effect improves the problem of valve closing insufficient pressure, and adjusting nut 14 can change back pressure cavity and connect area with discharge chamber, regulation The blowdown of a safety valve of valve.The steam of discharge chamber is discharged into safety place by discharge nozzle, is not directly discharged in air, regulation Between nut 14 and aerofluxus lumen pore, the design of rational gap, makes the quantity of steam being discharged into valve surrounding be preferably minimized.

The nuclear power main steam relief valve of this programme is not only by the property of back pressure cavity Yu the mode control valve of discharge chamber Energy index, also has traditional regulating measure using upper and lower adjusting ring, and specifically valve seat top is arranged with lower adjusting ring, valve Under side portion correspondence, the position of adjusting ring is provided with lower adjusting ring support pin through hole, is provided with lower adjusting ring in lower adjusting ring support pin through hole Support pin, screws in lower adjusting ring support pin and pushes against lower adjusting ring.Fairlead bottom is arranged with adjusting ring, and valve body-side correspondence regulates The position of circle is provided with adjusting ring support pin through hole, is provided with adjusting ring support pin in upper adjusting ring support pin through hole, and screw-in regulates Circle support pin pushes against adjusting ring.By changing the performance indications of the position adjustments valve of upper and lower adjusting ring.Based on such scheme, The problem turning motionless to solve adjusting ring the most easily to kill, this programme have employed odd-pitch screw design, i.e. lowers Being provided with lower adjusting ring female thread inside pitch circle, valve seat upper outside is provided with valve seat external screw thread, and the central diameter of lower adjusting ring female thread is big In standard female central diameter, lower adjusting ring cooperatively forms inside and outside spiral shell by lower adjusting ring female thread with valve seat is externally threaded with valve seat Stricture of vagina connects.Being provided with adjusting ring female thread inside upper adjusting ring, fairlead lower outside is provided with fairlead external screw thread, upper adjusting ring The central diameter of female thread is more than standard female central diameter, and upper adjusting ring and fairlead are by the outer spiral shell of upper adjusting ring female thread and fairlead The internal and external threads that cooperatively forms of stricture of vagina connects.Valve seat 1.2 and lower adjusting ring 2, fairlead are nonstandard with the connection screw thread of upper adjusting ring 6 Screw thread design, eliminates the phenomenon that thread biting locking under high temperature turns motionless.Further, so that flap seat stable be pressed on valve On lobe, it is to avoid producing relative motion and collision at the volley, this programme is also arranged with flap nut, valve on above-mentioned valve rod one end Flap seat, flap and valve rod are connected by lobe nut.

The steam security valve of this programme, in order to be able to meet the requirement of change unlatching pressure, is additionally provided with regulator, specifically On the valve rod other end, slip cap is provided with adjustment screw rod, adjusts bottom the upper end pass-out valve gap of screw rod, and the lower end adjusting screw rod pushes against Upper spring seat, adjusts the part bottom screw rod pass-out valve gap and is provided with locking nut, and locking nut is formed inside and outside with adjusting screw rod Threaded, locking nut is fixed on the outside bottom valve gap, rotates adjustment screw rod and regulates the preload pressure on spring.For Improve the power transmission connected mode of lower end and the upper spring seat adjusting screw rod, reduce abrasion between the two, the adjustment spiral shell of this programme Bar lower end is connected by thrust bearing device with upper spring seat, and thrust bearing device includes that thrust bearing and thrust bearing connect Seat, the seat ring of thrust bearing is fixed in the bearing saddle bore of upper spring seat, and thrust bearing connects seat and is fixed on the axle of thrust bearing On circle, adjust screw rod lower end push against thrust bearing connect seat, when adjust screw rod rotate into and out of time, drive thrust bearing rotate, from And avoid both contact frictions, improve the service life of transmission efficiency and device.Further, this programme is at such scheme On the basis of in order to meet nuclear power main steam relief valve to shock test (seismic behavior 1A) and minimum natural frequency (>= Requirement 33Hz), this programme also takes the scheme that valve rod 3 constraint guides, and specifically on the valve rod other end, fixed cover is provided with Lining, the valve rod other end by lining with adjust that screw rod formed can the spacing socket of radial direction of axially opposing slip.Valve rod passes valve Being arranged with locating ring in the part of lid connected entrance end, valve rod is formed by locating ring can axially opposing slide with valve gap connected entrance end The spacing connection of radial direction.During valve event, the shock test of valve rod 3 constraint guiding, beneficially valve and guarantee valve Door stable performance, such as Fig. 2, shown in 3 and 4, above-mentioned 3 is fairlead 8, locating ring 15 and lining 25 respectively.

So that valve rod bottom pass-out valve gap and adjust screw rod from outside interference and destruction, this programme also exists It is additionally arranged the partial shrouds bottom protective cover, specifically valve rod other end pass-out valve gap on bottom valve gap and is provided with protective cover, protection Having spacing keyhole bottom cover, be provided with limited bolt in spacing keyhole, limited bolt limits the movement travel of the valve rod other end.Limited bolt The movement travel of valve rod can be limited in the range of setting, thus avoid and cause flap because steam pressure is too high in pipeline The phenomenon of collision friction is produced, it is also possible to control flap by limited bolt and fill between the valve internal part that device is excessively opened and occurred Put the upper limit of unlatching, thus control the flow area of valve.When system needs to carry out water pressure test for strength, examination is installed in keyhole Test depression bar and withstand the end of valve rod, make valve be in closedown sealing state.

The nuclear power main steam relief valve of this programme mainly by valve body 1.1, valve seat 1.2, flap 3, flap seat 7, fairlead 8, Flap nut 9, lower adjusting ring 2, upper adjusting ring 6, radiator 10, adjusting nut 14, vent connection 30, valve gap 20, locating ring 15, Lower spring cup 18, upper spring seat assembly 21, spring 19, valve rod 17, adjustment screw rod 24, lining 25, adjusting ring support pin 4,5 composition. In normal conditions, valve is closed, and when upstream pressure reaches the set-pressure value of relief valve, valve starts to open Discharge medium, system pressure declines, and when system pressure drops to blow pressure, valve is automatically switched off, thus plays system super Pressure protective effect.The seismic behavior of nuclear power main steam relief valve is 1A, natural frequency requirement >=33HZ.Main steam safety valve is dynamic During work, flap 3, flap seat 7, flap nut 9, valve rod 17, adjusting nut 14, lower spring cup 18 are moving components, remaining Part does not moves.In the bottom of valve rod 17, flap seat 7 is by the constraint of fairlead 8, and at the middle part of valve rod 17, valve rod 17 is positioned The constraint of ring 15, at the top of valve rod 17, valve rod 17 is by the constraint of lining 25.The constraint at these three position makes the moving component can only Move up and down along valve vertical centrage, enhance the rigidity of these motion parts, it is ensured that the natural frequency of whole deck valve door >=33HZ, and shock test can be passed through.If middle part and bottom do not retrain, these local part (motion parts) For flexibility, its natural frequency will be less than 33HZ, will affect the natural frequency of whole valve.Three positions of valve rod are constrained simultaneously, Spring force can be delivered evenly on valve sealing face, be conducive to improving sealing property and the performance of valve.This programme Back pressure cavity is formed, by radiator 10 He by radiator 10, valve rod 17, fairlead 8, flap seat 7, flap nut 9, adjusting nut 14 Adjusting nut 14 forms discharge chamber, and valve is when opening, and flap 3, flap seat 7, flap nut 9, valve rod 17 move upwardly together, Between adjusting nut 14 and radiator 10, medium flow area is gradually increased along with Lift, and Pressure in Back-pressure Cavity reduces, profit In valve opening.Otherwise, during valve closing, along with the closedown of valve, between adjusting nut 14 and radiator 10, medium circulation cuts Face tapers into, and Pressure in Back-pressure Cavity increases, and beneficially valve closing makes valve than relatively low blowdown of a safety valve seat next time.From the back of the body Outside the steam depolarization pressing chamber to flow to discharge chamber escapes at least partially through gap between adjusting nut 14 and radiator 10, major part is steamed Vapour is discharged to safety place by vent connection 30.Valve seat 1.2 and lower adjusting ring 2, fairlead 8 and the connection screw thread of upper adjusting ring 6 Design for nonstandard screw thread pair, lower adjusting ring 2 and upper adjusting ring 6 for female thread, more slightly larger than standard thread, so connect screw thread pair Between gap-ratio standard thread gap big, eliminate thread biting locking under high temperature and turn motionless phenomenon.

The nuclear power main steam relief valve of this programme has following features compared with existing steam security valve.

1., compared with conventional thermal power station's steam security valve, nuclear power main steam relief valve adds antiseismic requirement and intrinsic Frequency is not less than the requirement of 33HZ.Conventional thermal power station relief valve only has the bottom of valve rod, and constrained (flap seat is transported in fairlead Dynamic), the top of valve rod is relatively big with the gap adjusting screw rod, can make less swing.And nuclear power main steam relief valve valve rod Bottom, middle part and top are the most constrained, and moving component can only move up and down along valve vertical centrage, enhance these fortune The rigidity of dynamic parts, it is ensured that the natural frequency >=33HZ of whole deck valve door, and shock test can be passed through.Valve rod three simultaneously Individual position is constrained, can be delivered evenly on valve sealing face by spring force, is conducive to provide the sealing property of valve and moves Make performance.

2. conventional steam relief valve does not has back pressure cavity and discharge chamber, overpressure and blowdown of a safety valve to be by upper and lower regulation Circle regulation, regulating measure is limited, and after relief valve is opened, substantial amounts of steam is directly discharged in surrounding.Nuclear power main steam is pacified Full valve adds the design of back pressure cavity and discharge chamber, and blowdown of a safety valve is in addition to can regulating by upper adjusting ring 6, lower adjusting ring 2, also Can be regulated by adjusting nut 14.It is discharged to the steam depolarization of discharge chamber at least partially through adjusting nut 14 and heat radiation from back pressure cavity Between device 10 outside the effusion of gap, major part steam is discharged to relief valve place by vent connection 30.

3. the upper and lower adjusting ring of conventional steam relief valve designs for standard thread, and during threaded engagement, gap is less, in high temperature work Under condition, screw thread is easily killed and is turned motionless, it is impossible to realize field adjustable.Nuclear power main steam valve base of safety valve 1.2 and lower adjusting ring 2, Fairlead 8 is nonstandard screw thread design with the connection screw thread of upper adjusting ring 6, connects the gap-ratio standard thread gap between screw thread big, Eliminate thread biting locking under high temperature and turn motionless phenomenon.

Based on above feature, the nuclear power main steam relief valve of this programme is compared currently existing scheme and is had substantive distinguishing features and enter Step.

The nuclear power main steam relief valve of this programme is not limited to the content disclosed in detailed description of the invention, occurs in embodiment Technical scheme can be with individualism, it is also possible to mutually comprise, those skilled in the art according to this programme combine common knowledge make The simple alternative gone out falls within the scope of this programme.

Claims (9)

1. a nuclear power main steam relief valve, is characterized in that including valve body, radiator and Elastic valve core device, described valve body includes The valve body inlet port, the radiator connected entrance end being located at described valve body top that are located at described valve body lower portion, it is located at described valve body The valve body outlet port of sidepiece, the valve body chamber of described valve inner, connect with described valve body inlet port bottom described valve body chamber Place is provided with valve seat, and described radiator includes being located at the valve body connected entrance end of described bottom radiator, being located at described radiator top Valve gap connected entrance end, radiator chamber within described radiator, described valve body connected entrance end and described radiator connected entrance end Fixing connection, described Elastic valve core device includes feather valve lever apparatus and is located at the endoceliac Valve clack device of described valve, described valve Lobe device includes flap, flap seat, fairlead, and described flap is slidably located in institute by the flap seat being pressed on described flap Stating in fairlead, the upper end of described fairlead connects with described valve body connected entrance end and is formed at described flap seat with described valve body even Back pressure cavity between port end, described feather valve lever apparatus includes valve rod, the spring members being set on described valve rod, is located at Valve gap outside described spring members, described valve gap is fixing with described valve gap connected entrance end to be connected, and one end of described valve rod passes institute Stating flap seat to push against described flap to be pressed on described valve seat and block described valve body air intake end, the other end of described valve rod depends on Secondary bottom valve gap described in pass-out after described valve body connected entrance end, described valve gap connected entrance end, through described radiator chamber Described valve rod is provided with, with gusset in described valve body connected entrance end, the discharge chamber set along described valve rod circumference ring, and described valve rod is with described Being arranged with adjusting nut in the part that discharge chamber is corresponding, described adjusting nut forms slipper seal with described discharge chamber and is connected, institute Stating discharge chamber to be connected with described back pressure cavity by the gap produced of sliding with described adjusting nut, described discharge chamber is connect by aerofluxus Manage external aerofluxus, described spring members include the lower spring cup being fixed on described valve rod, the spring being set on described valve rod, Being fixed on the upper spring seat within described valve gap, the described valve rod other end is through at the bottom of valve gap described in pass-out after described upper spring seat Portion, one end of described spring is fixing with described lower spring cup to be connected, and the other end of described spring is fixing with described upper spring seat even Connect；

High steam is by described flap upwards jack-up, and described adjusting nut moves upward with described valve rod and produces between described discharge chamber Raw gap, the steam in described back pressure cavity passes through described vent connection discharge valve after entering described discharge chamber along described gap, Described valve rod drives downwards described adjusting nut gradually with the decline of steam pressure in pipeline under the action of said spring means Blocking described gap, described back pressure cavity internal gas pressure gos up, and described flap blocks described valve body inlet port.

Nuclear power main steam relief valve the most according to claim 1, it is characterised in that described valve seat top is arranged with lower regulation Circle, the position of the corresponding described lower adjusting ring of described valve body-side is provided with lower adjusting ring support pin through hole, described lower adjusting ring support pin It is provided with lower adjusting ring support pin in through hole, screws in described lower adjusting ring support pin and push against described lower adjusting ring；Described fairlead bottom is overlapped Being provided with adjusting ring, the position of the corresponding described upper adjusting ring of described valve body-side is provided with adjusting ring support pin through hole, described on It is provided with adjusting ring support pin in adjusting ring support pin through hole, screws in described upper adjusting ring support pin and push against described upper adjusting ring.

Nuclear power main steam relief valve the most according to claim 2, it is characterised in that be provided with downward inside described lower adjusting ring Pitch circle female thread, described valve seat upper outside is provided with valve seat external screw thread, and the central diameter of described lower adjusting ring female thread is more than in standard The pitch diameter of thread, described lower adjusting ring coordinates shape with described valve seat by described lower adjusting ring female thread is externally threaded with described valve seat Internal and external threads is become to connect；Being provided with adjusting ring female thread inside described upper adjusting ring, described fairlead lower outside is provided with guiding Set external screw thread, the central diameter of described upper adjusting ring female thread is more than standard female central diameter, described upper adjusting ring and described fairlead It is connected by the described upper adjusting ring female thread internal and external threads that cooperatively forms externally threaded with described fairlead.

Nuclear power main steam relief valve the most according to claim 1, it is characterised in that be also arranged with valve on described valve rod one end Lobe nut, described flap seat, described flap and described valve rod are connected by described flap nut.

Nuclear power main steam relief valve the most according to claim 1, it is characterised in that slide on the described valve rod other end sheathed Having adjustment screw rod, bottom valve gap described in the upper end pass-out of described adjustment screw rod, the lower end of described adjustment screw rod pushes against described upper bullet Spring abutment, the part bottom valve gap described in described adjustment screw rod pass-out is provided with locking nut, described locking nut and described adjustment Screw rod forms internal and external threads and connects, and described locking nut is fixed on the outside bottom described valve gap, rotates described adjustment screw rod Regulate the preload pressure on described spring.

Nuclear power main steam relief valve the most according to claim 5, it is characterised in that described adjustment screw rod lower end with described on Spring base is connected by thrust bearing device, and described thrust bearing device includes that thrust bearing and thrust bearing connect seat, described The seat ring of thrust bearing is fixed in the bearing saddle bore of described upper spring seat, and described thrust bearing connects seat and is fixed on described thrust On the blowout patche of bearing, described adjustment screw rod lower end pushes against described thrust bearing and connects seat.

Nuclear power main steam relief valve the most according to claim 5, it is characterised in that fix sheathed on the described valve rod other end Having lining, the described valve rod other end is formed by described lining and described adjustment screw rod can the radial direction stop collar of axially opposing slip Connect.

Nuclear power main steam relief valve the most according to claim 7, it is characterised in that described valve rod connects through described valve gap Being arranged with locating ring in the part of mouthful end, described valve rod can axial phase by described locating ring and the formation of described valve gap connected entrance end To the spacing connection of radial direction slided.

Nuclear power main steam relief valve the most according to claim 1, it is characterised in that valve described in described valve rod other end pass-out Partial shrouds bottom lid is provided with protective cover, has spacing keyhole, be provided with spacing in described spacing keyhole bottom described protective cover Bolt, described limited bolt limits the movement travel of the described valve rod other end.