CN212928893U

CN212928893U - Pilot operated safety valve

Info

Publication number: CN212928893U
Application number: CN202020747840.5U
Authority: CN
Inventors: 万胜军; 陈建军; 胡逸轩; 侯志蓉; 丁佳鹏; 李庆华; 孙明宇; 李大猛
Original assignee: Harbin Power Plant Valve Co ltd; China Nuclear Power Engineering Co Ltd
Current assignee: Harbin Power Plant Valve Co ltd; China Nuclear Power Engineering Co Ltd
Priority date: 2020-05-01
Filing date: 2020-05-01
Publication date: 2021-04-09
Anticipated expiration: 2030-05-01

Abstract

The utility model relates to a pilot operated relief valve, it is by the main valve body, the main valve seat, the main valve lamella, the uide bushing, main spring, main valve gap and pilot valve are constituteed, wherein the pilot valve is by leading the valve body, a disk seat, lower regulating ring, go up the regulating ring, a valve clack, a valve uide bushing, balanced piston, a valve spring, a valve rod, the spring housing, first jump ring, secondary valve bush, secondary valve piston, the second jump ring, the export valve gap, adjust the plug screw, spring energy storage circle, secondary valve spring, the secondary disk seat, secondary valve clack is constituteed. Set up balanced piston on the primary valve rod of pilot valve, the valve body outlet side of pilot valve sets up the orifice, and the outlet valve covers and sets up the regulation plug screw, sets up hydrophobic hole on the guide valve body, sets up hydrophobic groove on the secondary valve bush of pilot valve. The utility model provides a hydrophobic problem of comdenstion water, reduced secondary valve piston and secondary valve bush steam medium leakage within a definite time, reduced the influence that the valve pocket backpressure changes action performance such as open and close to the valve.

Description

Pilot operated safety valve

Technical Field

The invention relates to a pilot operated safety valve, and belongs to valves used in the fields of electric power, new energy, petrifaction and the like.

Background

The pilot operated safety valve required in the fields of electric power, new energy, petrochemical industry and the like consists of a main valve and a pilot valve. There can media such as vapor to be detained in the valve pocket at relief valve take-off closing in-process, can be detained in valve body low-lying department and piston epicoele after the medium condensation, the pilot valve of general pilot operated safety valve does not set up hydrophobic means, the comdenstion water is detained for a long time and can be made spare part rust, corrode, seriously influence valve life, when the relief valve is taken off the jump once more simultaneously, the comdenstion water is heated can evaporate and sharp inflation, become steam-water mixture, it can produce the erosion to spare part at the drive of discharging the steam medium under the rapid flow, seriously influence the performance of relief valve. In addition, the piston of the pilot valve is generally provided with a piston ring, so that the leakage amount is large, and the piston thrust is greatly reduced. The above problems are urgently needed to be solved.

Disclosure of Invention

The invention aims to provide a pilot operated safety valve, which comprises a pilot valve and a main safety valve, wherein the pilot valve is arranged on a valve cover of the main safety valve. The invention solves the problems of condensate retention of the pilot valve, small piston thrust and the like, and improves the service life of the valve and the reliability of the action performance.

The technical scheme of the invention is to provide a pilot operated safety valve, which comprises a main valve body, a main valve seat, a main valve flap, a guide sleeve, a main spring, a main valve cover, a pilot valve and the like, wherein the pilot valve comprises a guide valve body, a primary valve seat, a lower adjusting ring, an upper adjusting ring, a primary valve flap, a primary valve guide sleeve, a balance piston, a primary valve spring, a primary valve rod, a spring cover, a first snap spring, a secondary valve bushing, a secondary valve piston, a second snap spring, an outlet valve cover, an adjusting screw plug, a spring energy storage ring, a secondary valve spring, a secondary valve seat and a secondary valve flap. The balance piston is sleeved on a primary valve rod of the pilot valve and fixed by a first clamp spring, the outer diameter of the balance piston is the same as the diameter of a sealing surface of the primary valve clack, and the influence of the back pressure change of the pilot valve cavity on the action performance of the valve can be reduced.

The invention solves the problems of condensate water retention, small piston thrust and the like of the pilot valve in the closed state of the safety valve, and the drain hole is arranged on the guide valve body of the pilot operated safety valve, the drain groove is arranged on the secondary valve bushing of the pilot valve, and the condensate water is discharged from the valve outlet through the drain hole and the drain groove. And a secondary valve piston of the pilot valve is provided with a spring energy storage ring, so that a gap between the secondary valve piston and a secondary valve bushing is reduced.

The outlet side of the valve body of the pilot valve is provided with a throttling hole, the outlet valve cover is provided with an adjusting screw plug with a conical head, the medium pressure in the cavity of the pilot valve body can be adjusted, and the pressure of the return seat of the valve can be adjusted.

The invention has the beneficial effects that: according to the pilot operated safety valve, the drain hole is formed in the pilot valve body, the drain groove is formed in the secondary valve bushing of the pilot valve, and condensed water is discharged through the drain hole and the drain groove, so that parts are effectively prevented from being corroded and eroded; the secondary valve piston of the pilot valve is provided with the spring energy storage ring, so that the leakage of steam medium between the secondary valve piston and the secondary valve bushing is reduced, and the thrust of the piston is greatly improved. The steam discharge area can be adjusted through the throttling hole and the adjusting screw plug which are arranged on the guide valve body and the outlet valve cover, and the recoil pressure and the opening and closing pressure difference of the safety valve can be finely adjusted.

Drawings

FIG. 1 is a schematic view of a pilot operated safety valve

FIG. 2 is a schematic diagram of a pilot valve

FIG. 3 is a partial structure diagram (1) of the pilot valve

FIG. 4 is a partial structure diagram (2) of the pilot valve

FIG. 5 is a schematic view of the structure of a secondary valve bushing

In the figure, 1, a main valve body, 2, a main valve seat, 3, a main valve clack, 4, a guide sleeve, 5, a main spring, 6, a main valve cover, 7, a pilot valve, 7-1, a pilot valve body, 7-2, a primary valve seat, 7-3, a lower adjusting ring, 7-4, an upper adjusting ring, 7-5, a primary valve clack, 7-6, a primary valve guide sleeve, 7-7, a balance piston, 7-8, a primary valve spring, 7-9, a primary valve rod, 7-10, a spring cover, 7-11, a first snap spring, 7-12, a secondary valve bush, 7-13, a second snap spring, 7-14, a secondary valve piston, 7-15, an outlet valve cover, 7-16, an adjusting screw plug, 7-17, a spring energy storage ring, 7-18, a secondary valve spring, 7-19, a secondary valve seat, 7-14, a second snap spring, a, 7-20 secondary valve clack, 7-21 oblique drain hole, 7-22 horizontal drain hole, 7-23 drain groove and 7-24 throttle hole

Detailed Description

In the embodiment shown in figure 1, the invention provides a pilot operated safety valve which comprises a main valve body 1, a main valve seat 2, a main valve flap 3, a guide sleeve 4, a main spring 5, a main valve cover 6 and a pilot valve 7, wherein the pilot valve 7 comprises a guide valve body 7-1, a primary valve seat 7-2, a lower adjusting ring 7-3, an upper adjusting ring 7-4, a primary valve flap 7-5, a primary valve guide sleeve 7-6, a balance piston 7-7, a primary valve spring 7-8, a primary valve rod 7-9, a spring cover 7-10, a first snap spring 7-11, a secondary valve bush 7-12, a second snap spring 7-13, a secondary valve piston 7-14, a valve cover outlet 7-15, an adjusting screw plug 7-16, a spring energy storage ring 7-17, a secondary valve spring 7-18, a secondary valve seat 7-19, a secondary valve, 7-20 parts of secondary valve clack.

As shown in fig. 1, 2 and 3, when the medium is over-pressurized, the medium pushes the primary valve flap 7-5 to compress the primary valve spring 7-8, so that the primary valve flap 7-5 is opened, the discharged medium enters the secondary valve piston chamber, the secondary valve piston 7-14 is pushed to move downwards, the secondary valve flap 7-20 is pushed to move downwards and open, the medium in the upper chamber of the main valve flap 3 is discharged, the medium pressure in the upper chamber of the main valve flap 3 is rapidly reduced, and the high-pressure medium in the lower chamber pushes the main valve flap 3 to open.

In the opening and closing process of the pilot valve 7, the back pressure in the valve cavity of the pilot valve body 7-1 changes greatly, in order to avoid the influence of the change of the back pressure on the performance of the valve, a balance piston 7-7 is arranged on a primary valve rod 7-9 and is fixed by a first clamp spring 7-11, the outer diameter of the balance piston 7-7 is the same as the diameter of a sealing surface of a primary valve clack 7-5, and the influence of the change of the back pressure in the valve cavity on the take-off pressure and the recoil pressure of the valve is eliminated.

As shown in figures 2, 3, 4 and 5, the secondary valve piston 7-14 is provided with the spring energy storage ring 7-17, so that the clearance between the secondary valve piston 7-14 and the secondary valve bushing 7-12 is reduced, the leakage amount of steam medium is reduced, and the thrust of the secondary valve piston 7-14 is greatly improved.

After the safety valve is tripped and closed, a large amount of steam medium is retained in the cavity of the pilot valve body and condensed into liquid, and liquid water is retained in the cavity for a long time to cause corrosion of the pilot valve body 7-1 and internal parts, so that the service life of the valve is seriously influenced; in addition, after the valve is opened again, the condensed water is heated and expands to generate harmful phenomena such as water hammer and the like. The inner diameter of the secondary valve bushing 7-12 is provided with a drain groove 7-23, the pilot valve body 7-1 is provided with a horizontal drain hole 7-22, and the condensed water on the upper part of the secondary valve piston 7-14 is discharged out of the pilot valve 7 body through a drain channel formed by the drain groove 7-23 and the horizontal drain hole 7-22. The lowest part of the guide valve body 7-1 is provided with an inclined drainage hole 7-21, so that the condensed water in the guide valve body 7-1 is discharged through the inclined drainage hole 7-21.

The pilot valve body 7-1 is provided with an orifice 7-24, the outlet valve cover 7-15 is provided with an adjusting screw plug 7-16, the head of the adjusting screw plug 7-16 is conical, the outlet valve cover 7-15 is in threaded connection with the adjusting screw plug 7-16, the flow area of the orifice 7-24 is changed by adjusting the adjusting screw plug 7-16, and then the recoil pressure and the opening and closing pressure difference of the safety valve are finely adjusted and controlled.

Claims

1. A pilot operated safety valve comprises a main valve body (1), a main valve seat (2), a main valve flap (3), a guide sleeve (4), a main spring (5), a main valve cover (6) and a pilot valve (7), wherein the pilot valve (7) comprises a guide valve body (7-1), a primary valve seat (7-2), a lower adjusting ring (7-3), an upper adjusting ring (7-4), a primary valve clack (7-5), a primary valve guide sleeve (7-6), a balance piston (7-7), a primary valve spring (7-8), a primary valve rod (7-9), a spring cover (7-10), a first snap spring (7-11), a secondary valve bush (7-12), a second snap spring (7-13), a secondary valve piston (7-14), an outlet valve cover (7-15), an adjusting screw plug (7-16), The spring energy storage ring (7-17), the secondary valve spring (7-18), the secondary valve seat (7-19) and the secondary valve clack (7-20); the method is characterized in that: an orifice (7-24) is arranged on the valve guide body (7-1), an adjusting screw plug (7-16) is arranged on the outlet valve cover (7-15), and the head of the adjusting screw plug (7-16) is conical.

2. A pilot operated safety valve according to claim 1, wherein: the guide valve body (7-1) is provided with an inclined drain hole (7-21) and a horizontal drain hole (7-22).

3. A pilot operated safety valve according to claim 1, wherein: the secondary valve bush (7-12) is provided with a drainage groove (7-23).

4. A pilot operated safety valve according to claim 1, wherein: spring energy storage rings (7-17) are arranged on the secondary valve pistons (7-14).