CN2427692Y

CN2427692Y - Piston damping guiding type safety valve

Info

Publication number: CN2427692Y
Application number: CN 00223139
Authority: CN
Inventors: 王元清
Original assignee: CHANGJIANG INSTR FACTORY LESHA
Current assignee: CHANGJIANG INSTR FACTORY LESHA
Priority date: 2000-05-27
Filing date: 2000-05-27
Publication date: 2001-04-25
Anticipated expiration: 2010-05-27

Abstract

The utility model relates to a piston damping guiding type safety valve, which comprises a main valve, a pilot valve and a connecting pipe, wherein the main valve adopts a self tightening type structure. A column step-shaped valve core of the main valve is cooperated with a valve sleeve with a step-shaped inner hole, and a sealing gas chamber is composed of a small end surface of the valve core, an inner cavity of the valve sleeve and an inner chamber of an upper valve cover; the pilot valve adopts a piston damping structure, and a valve rod of the pilot valve is processed with a piston into integration; a damping groove is opened at the external circle of the piston, and an end surface is provided with damping orifices. Two sealing gas chambers are formed respectively form an upper and a lower end surfaces of the piston, facing a dummy club inner cavity of a valve body, an inner cavity of a middle valve box and an inner cavity at the upper end of a valve seat. The valve which can be opened in a pressure range which is similar to a set pressure range has the advantages of exact reposition, stable operation, small starting and closing pressure differences and reliable back base sealing.

Description

Piston damping Pilot operated safety valve

The utility model belongs to the valve class, particularly a kind of piston damping Pilot operated safety valve that is applicable to equipment such as oil-gas gathering and transferring pipeline device, boiler, container.

At present, in device systems such as oil, rock gas, chemical pipeline device, boiler, container, usually adopt traditional Direct spring loaded safety valve to make safety protection equipment, because there is shortcomings such as can not opening accurately that jumpings, Blowdown of a safety valve are big, be difficult for resetting, return seat sealing leakage easily after the action, amount of maintenance is big in this safety valve.The claimant was in " balanced linear is carried the lotus safety valve " (patent No.: 99231771.1) in first to file in 1999, though the area pressure balance relation of utilizing pressure medium that spool step place is produced has solved the problem that Direct spring loaded safety valve exists, but aspect big latus rectum, high pressure, quick drain amount, yet do not satisfy working condition safety protection requirement fully.

The purpose of this utility model is for overcoming the deficiency of the said goods design, reach open jump accurately, the Blowdown of a safety valve scope is little, working stability, to return the seat sealing reliable, and can satisfy safety protection requirements such as high pressure, big latus rectum, quick drain simultaneously, and design a kind of piston damping Pilot operated safety valve.

The purpose of this utility model is achieved through the following technical solutions:

Piston damping Pilot operated safety valve, comprise main valve, pilot valve and PRESSURE PIPE, main valve links to each other by PRESSURE PIPE with pilot valve, pilot valve drives main valve events by the pressure sensor signalizing activity, main valve and pilot valve are made of separately valve body, valve seat, spool, valve rod, spring, valve gap respectively, valve core of main valve is the cylinder stepped shape, matches with the valve pocket with stepped shape endoporus, it is characterized in that:

A. the little end surface of the cylinder stepped shape spool of main valve and valve pocket inner chamber, bonnet inner chamber are formed sealed air chamber, pilot valve and main valve bonnet bore seal air chamber are connected by PRESSURE PIPE by the main valve entrance point, the surface of contact of spool major part upper-end surface and valve pocket inner chamber step is the total travel confined planes of spool;

B. the body cavity of pilot valve is shaped on the valve seat of band conical surface boss, and the valve body upper-end surface is shaped on guiding stroke boss, and the feather edge of boss has the runner hole, communicates with the inner chamber and the exhaust outlet of valve body respectively;

C. pilot valve valve rod and piston are processed as an integral body, the valve rod upper and lower part has the seal with O ring groove, the cylindrical of piston has damping slot and seal with O ring groove, and piston end face has damping hole, and stem lower portion is connected by O-ring seals, silk pressing circle and spool and is one;

D. the upper and lower end face of pilot valve piston is formed two sealed air chamber for valve body boss inner chamber, middle valve cap inner chamber, valve seat upper end inner chamber respectively.

The utility model is the following technical characteristics of tool also:

The bottom inner chamber of valve core of main valve is embedded with the soft seal rubber pad, forms hard soft pair of matter sealing with the conical surface boss of valve seat and pays.

The sulfuration of pilot valve spool bottom has rubber pad, forms hard soft pair of matter sealing with valve seat conical surface boss and pays.

The utility model compared with prior art has the following advantages:

1. valve core of main valve adopts the cylinder stepped shape, matches with valve pocket step inner chamber, and its little end surface, valve pocket inner chamber, bonnet inner chamber have been formed sealed air chamber, and step spool microcephaly area has satisfied the sealability requirement greater than the valve base sealing area; The major part area of step spool is greater than microcephaly's area, is beneficial to the spacing of the unlatching of main valve and stroke.

2. press the pilot valve valve core structure, the sealing area of pilot valve spool is less than piston area, when pressure medium reaches setting pressure, valve core sealed cover is subjected to the medium thrust that makes progress to become piston area and be subjected to the medium thrust that makes progress, pressurized produces between sealing surface " adsorption effect " and spring force have been overcome fully, pilot valve is opened discharging in very near the scope of setting pressure, the pressure medium of the step spool small end epicoele of main valve discharges immediately, and the big end of step spool is opened discharging fast under pressure medium promotes.

When 3. pilot valve is opened, pressure medium enters piston upper chamber by the piston damping hole, and communicate with valve body boss edge aperture and valve body exhaust outlet with middle valve cap inner chamber matching gap by the valve body boss, make the piston upper and lower end in opening-closing process, form a kind of hydromechanics dynamic equilibrium relation, its Blowdown of a safety valve scope is realized under physical dimension preset proportion relation.This safety valve can be opened in very near the setting pressure scope, resets accurately, and working stability, Blowdown of a safety valve is little, returns the seat sealing reliably, can satisfy the application under the high parameter technical specifications.

Fig. 1 is the utility model embodiment's a structural representation;

Fig. 2 is the structural representation of pilot valve.

According to accompanying drawing embodiment structure of the present utility model is further described below:

As shown in Figure 1, piston damping Pilot operated safety valve partly is made up of main valve, pilot valve 10 and PRESSURE PIPE 9 three, and main valve links to each other by PRESSURE PIPE with pilot valve.Main valve adopts the self tightening structure, constitute by its valve body 1, valve seat 2, spool 5, spring 7, bonnet 8 etc., valve seat 2 main valve body 1 inner chamber of packing into, valve core of main valve 5 is the cylinder stepped shape, match with the valve pocket 6 with stepped shape endoporus and to pack into, the valve pocket bottom end is pressed on the valve seat large end face and makes it fixing.Be embedded with O-ring seals 4 on the cylndrical surface at valve core of main valve 5 two ends, its little end surface is pressed with spring 7, and forms sealed air chamber with valve pocket 6 inner chambers, bonnet 8 inner chambers, and bonnet 8 end faces and valve body upper-end surface are connected as one by bolton.The main valve entrance point is connected pilot valve 10 and main valve bonnet 8 bore seal air chambers by PRESSURE PIPE 9, and the surface of contact of valve core of main valve 5 major part upper-end surfaces and valve pocket 6 inner chamber steps is the total travel confined planes of spool 5.The conical surface boss of valve seat 2 and valve core of main valve 5 bottom end built-up welding have cemented carbide, and inner chamber is embedded with soft seal rubber pad 3 in the bottom of spool 5, form hard soft pair of matter sealing with the conical surface boss of valve seat 2 and pay.

As shown in Figure 2, pilot valve adopts the piston damping structure, form by valve body 11, spool 13, valve seat 12, valve rod 24, piston 17, spring 25, loam cake 26, adjusting screw rod 27 etc., valve body 11 inner chambers of pilot valve 10 directly are processed with the valve seat 12 of band conical surface boss, valve body 11 upper-end surfaces are shaped on guiding stroke boss 30, the feather edge of boss 30 has runner hole 19, communicates with the inner chamber and the exhaust outlet 21 of valve body 11 respectively.Pilot valve valve rod 24 and piston 17 are machined directly to an integral body, valve rod 24 upper and lower parts have seal with O ring groove 23, the cylindrical of piston 17 has damping slot 18 and seal with O ring groove 16, have damping hole 20 between the upper and lower end face of piston 17, valve rod 24 bottoms are connected in the bottom with spool 13 by O-ring seals 14, silk pressing circle 15.Valve rod 24 upper end portions are pressed with spring 25, adjusting screw rod 27, and by middle valve cap 22 endoporus guide-localizations, middle valve cap upper end connects loam cake 26, and by bolt loam cake 26, middle valve cap 22, valve body 11 is fused on the stem diameter.

The upper and lower end face of piston 17 is formed two sealed air chamber for valve body boss 30 inner chambers, middle valve cap 22 inner chambers, valve seat 12 upper end inner chambers respectively.The sulfuration of pilot valve spool 13 bottoms has rubber pad 28, forms hard soft pair of matter sealing with valve seat 12 conical surface boss and pays.

The horizontal pore in pilot valve 10 lower ends is connected with main valve bonnet 8 through PRESSURE PIPE by joint 29, and the vertical pore in pilot valve lower end is connected to the below of valve body of main valve through PRESSURE PIPE.

Describe at several working staties of the present utility model below:

1. closed condition: now locate the position as main valve among Fig. 1, Fig. 2 and pilot valve spool, pressure medium enters the sealing ring casing that forms between pilot valve valve body 11 inner chambers and main valve bonnet 8 inner chambers and valve core of main valve 5 little end surfaces in main valve suction flange upper end by PRESSURE PIPE 9, under main spool spring 7 pretightening force effects, because spool microcephaly area is greater than the main valve sealing area, valve core of main valve 5 sealings are paid and are close to valve seat 2 raised head faces and the conical surface, form hard soft pair of matter sealing.Greater than seal pressure power, sealing surface is similarly two matter sealings and pays the power of pilot valve spring 25, has satisfied the usage requirement of closing sealing " zero leakage " when setting.

2. superpressure emissions status: when the tube equipment pressure medium is increased to setting pressure, the pilot valve spring force is subjected to the upwards thrust of pressure medium less than spool 13 sealing areas, spool 13 moves on valve body 11 boss inner chambers, at this moment pressure medium acts on the lower end surface of piston 17, because piston area is much larger than the seal spool area, piston 17 promotes to move on the valve rod 24, moves on the spool 13, and pilot valve is opened.Because of pilot valve valve body 11 inner chambers hold the sealing ring casing to be communicated with by PRESSURE PIPE with the cylinder step microcephaly of valve core of main valve 5, pilot valve is opened, spool 5 discharges by pilot valve valve outlet place with microcephaly's end pressure, down pressure reduces, spool 5 big end surface are moved up by pressure medium, when arriving valve pocket 6 inner chamber step intersections is total travel, the main valve discharging decompressing.

3. return the seat state: the tube equipment pressure medium reduces with the unlatching discharging of valve, when pressure medium drops to the certain pressure scope, pilot valve piston 17 upper ends are added when spring force makes progress thrust greater than piston lower end medium by pressure medium, pilot valve spool 13 moves down, and its time seat power value is by the hydromechanics dynamic equilibrium relation decision of design utilization.

Pilot valve piston 17 top and bottom this moment are connected by piston damping hole 20, and the piston upper end is stressed to be: the area that the area of piston 17 deducts valve rod 24 multiply by the active force that pressure medium adds upper spring 25, and the piston lower end is stressed multiply by pressure medium for piston area.And acting force of the spring is the seal pressure power of spool 13, and promptly to multiply by discharge pressure be spring force to sealing area.It is stressed greater than the piston lower end thrust that makes progress to return a condition that seat closes and be piston 17 upper ends, set up relationship according to fluid mechanics principle, the ratio of determining Reseating pressure of a safety valve and discharge pressure at last is the ratio of the fixed spool of designing institute 13 sealing areas and valve rod 24 areas, because of Reseating pressure of a safety valve is given by when design fully, so when the pipe medium pressure discharging drops to certain limit, pilot valve returns seat and cuts out, and main valve is closed thereupon.

Claims

1. piston damping Pilot operated safety valve, comprise main valve, pilot valve and PRESSURE PIPE, main valve links to each other by PRESSURE PIPE with pilot valve, main valve and pilot valve are made of separately valve body, valve seat, spool, valve rod, spring, valve gap respectively, valve core of main valve is the cylinder stepped shape, match with valve pocket, it is characterized in that with stepped shape endoporus:

A. the little end surface of the cylinder stepped shape spool (5) of main valve and valve pocket (6) inner chamber, bonnet (8) inner chamber are formed sealed air chamber, pilot valve (10) and main valve bonnet (8) bore seal air chamber are connected by PRESSURE PIPE (9) by the main valve entrance point, the surface of contact of spool (5) major part upper-end surface and valve pocket (6) inner chamber step is the total travel confined planes of spool (5);

B. valve body (11) inner chamber of pilot valve (10) is shaped on the valve seat (12) of band conical surface boss, valve body (11) upper-end surface is shaped on guiding stroke boss (30), the feather edge of boss (30) has runner hole (19), and inner chamber and the exhaust outlet with valve body (11) communicates respectively;

C. pilot valve valve rod (24) and piston (17) are processed as an integral body, valve rod (24) upper and lower part has seal with O ring groove (23), the cylindrical of piston (17) has damping slot (18) and seal with O ring groove (16), the end face of piston (17) has damping hole (20), and valve rod (24) bottom is connected with spool (13) by O-ring seals (14), silk pressing circle (15) and is one;

D. the upper and lower end face of piston (17) is formed two sealed air chamber for valve body boss (30) inner chamber, middle valve cap (22) inner chamber, valve seat (12) upper end inner chamber respectively.

2. piston damping Pilot operated safety valve as claimed in claim 1 is characterized in that the bottom inner chamber of valve core of main valve (5) is embedded with soft seal rubber pad (3), forms hard soft pair of matter sealing with the conical surface boss of valve seat (2) and pays.

3. as claim 1,2 described piston damping Pilot operated safety valves, it is characterized in that the sulfuration of pilot valve spool (13) bottom has rubber pad (28), form hard soft pair of matter sealing with valve seat (12) conical surface boss and pay.