CN204459183U - High-performance double seal bellows stop valve special for chlorine - Google Patents

Abstract

The utility model relates to a high-performance double-sealed bellows stop valve for chlorine gas, comprising a valve body, a valve disc, a valve stem, a valve cover, a bellows, and a hand wheel; mainly the upper end of the bellows is sealed and welded on the lower end surface of a stuffing box , the upper end surface of the stuffing box body and the upper end surface of the valve cover are sealed and welded, and graphite sealing packing is installed between the inner cavity of the stuffing box and the valve stem; the sealing surface of the valve disc adopts a soft and hard double sealing structure, and the inner sealing surface adopts surfacing welding The conical hard sealing surface is made of cemented carbide, and an annular groove is made on the lower end surface of the disc outside the conical hard sealing surface, and a polytetrafluoroethylene sealing ring is fixedly installed in the annular groove, and the inner cavity of the valve body channel is made of A conical hard sealing surface and a sealing plane that cooperate with the conical hard sealing surface on the disc and the polytetrafluoroethylene sealing ring. Its sealing performance is reliable, and it is suitable for the control valve of chlorine gas delivery pipeline.

Description

High performance double sealing bellows globe valve for chlorine gas

technical field

The utility model belongs to the field of valves, in particular to a bellows stop valve. The utility model is suitable for the control valve of the chlorine gas delivery pipeline.

Background technique

Due to the wide range of uses of liquid chlorine, it is generally used as a strong oxidant after gasification to be used as a licking material for the purification and disinfection of textiles, papermaking, polysilicon, PVC, and tap water. Liquid chlorine is highly irritating and corrosive. It can burn and explode when mixed with other flammable gases under sunlight. It can also react with most metals and cause corrosion to metals. Therefore, the sealing performance of the control valve of the chlorine gas delivery pipeline is very high. At present, the bellows stop valve is mostly used in the chlorine gas delivery system. The upper end of the bellows of the traditional bellows globe valve is generally welded on the mounting plate, and the mounting plate is sealed and installed between the valve body and the valve cover to realize the sealing of the middle cavity; the valve disc and the valve seat generally adopt a soft sealing structure. Its main disadvantages are: the bellows is easily corroded in the medium of liquid chlorine, causing internal leakage, resulting in external leakage of the medium, causing corrosion to the equipment and pollution to the environment; the soft sealing surface of the valve disc is easily damaged by impurities in the medium, causing Internal leakage, poor sealing reliability.

Contents of the invention

The purpose of the utility model is to provide a high-performance double-seal chlorine special bellows shut-off valve with reliable sealing performance against the shortcomings of the prior art.

The technical scheme of the utility model includes a valve body, a valve disc, a valve stem, a valve cover, a bellows, and a hand wheel. The nut is fixedly connected with the hand wheel, and a guide device is provided between the bracket and the valve stem. The lower end of the bellows is sealed and welded to the valve stem; The upper end faces of the bonnet are sealed and welded, and graphite sealing packing is installed between the inner cavity of the stuffing box and the valve stem; the sealing surface of the disc adopts a soft and hard double sealing structure, and the inner sealing surface is made of surfacing hard alloy with conical hard On the sealing surface, an annular groove is made on the lower end surface of the valve disc outside the conical hard sealing surface, and a polytetrafluoroethylene sealing ring is fixedly installed in the annular groove. The conical hard sealing surface and sealing plane that the sealing surface and the PTFE sealing ring cooperate with each other.

In the above technical solution, a metal gasket and a flexible graphite O-ring double sealing structure are used between the valve body and the valve cover.

The utility model has the advantages that the upper end of the bellows is welded with the seal, the stuffing box and the valve cover are sealed and welded, and the stuffing box and the sealing packing are installed to form a double sealing structure in the middle cavity; It adopts a hard-soft double seal structure. The inner hard seal pair has wear resistance to prevent impurities from damaging the seal pair. The outer layer soft seal pair cooperates with the valve body sealing seat to achieve zero leakage sealing, and the sealing reliability is good.

Description of drawings

Fig. 1 is a structural representation of the utility model.

1 Valve body, 2 Valve disc, 3 Valve stem, 4 Mounting block, 5 Bellows, 6 Metal gasket, 7 Bonnet, 8 Stuffing box body, 9 Graphite sealing packing, 10 Guide device, 11 Bracket, 12 Hand wheel, 13 stem nut, 14 packing gland, 15 flexible graphite O-ring, 16 polytetrafluoroethylene sealing ring.

Detailed ways

As shown in Figure 1, the high-performance double-sealed bellows globe valve for chlorine gas includes valve body 1, valve disc 2, valve stem 3, valve cover 7, bellows 5, and hand wheel 12. The back of valve disc 2 passes through installation block 4 It is fixedly installed on the lower end of the valve stem 3, and the upper end of the valve stem 3 passes through the valve stem nut 13 installed in the bracket 11 and is fixedly connected with the hand wheel 12. A guide device 10 is provided between the bracket 11 and the valve stem 3. The guide device 10 The rotary motion of the hand wheel 12 is converted into the linear motion of the valve stem 3. The lower end of the bellows 5 is sealed and welded to the valve stem 3; the upper end of the bellows 5 is sealed and welded to the lower end of the stuffing box body 8. 316L or Hastelloy C276 material with good performance, sealing welding between the upper end surface of the stuffing box body 8 and the upper end surface of the valve cover 7, graphite sealing packing 9 is installed between the inner cavity of the stuffing box body 8 and the valve stem 3, so that the middle cavity of the valve is formed by Double sealing structure composed of bellows 5 and graphite sealing packing 9. Graphite sealing packing 9 is pressed and installed in stuffing box body 8 by packing gland 14; The conical hard sealing surface is made of surfacing hard alloy. The hard alloy is made of Stellite alloy. An annular groove is made on the lower end surface of the valve disc 2 outside the conical hard sealing surface, and fixed in the annular groove. PTFE sealing ring 16, the PTFE sealing ring 16 is made of RPTFE reinforced PTFE, the inner cavity of the valve body 1 channel is made with a conical hard sealing surface on the valve disc 2 and a PTFE sealing ring 16 The conical hard sealing surface and sealing plane that cooperate with each other form a hard and soft double sealing structure between the valve disc 2 and the sealing seat of the valve body 1, and realize zero leakage sealing.

The metal gasket 6 and the flexible graphite O-ring 15 are double-sealed between the valve body 1 and the valve cover 7, and the metal gasket 6 is made of 316L corrosion-resistant alloy material.

Claims (2)

1. A high-performance double-sealed bellows stop valve for chlorine gas, including a valve body (1), a valve disc (2), a valve stem (3), a valve cover (7), a bellows (5), and a hand wheel (12 ), the back of the valve disc (2) is fixedly installed on the lower end of the valve stem (3) through the installation block (4), and the upper end of the valve stem (3) passes through the valve stem nut (13) installed in the bracket (11) and the handwheel ( 12) Fixed connection, a guide device (10) is provided between the bracket (11) and the valve stem (3), and the lower end of the bellows (5) is sealed and welded to the valve stem (3); the characteristic is that the upper end of the bellows (5) The sealing is welded on the lower surface of the stuffing box body (8), the sealing welding between the upper surface of the stuffing box body (8) and the upper surface of the bonnet (7), the inner cavity of the stuffing box body (8) and the valve stem (3) Graphite sealing packing (9) is installed between them; the sealing surface of the disc (2) adopts a soft and hard double sealing structure, and its inner sealing surface is made of surfacing hard alloy to make a conical hard sealing surface, and the outer side of the conical hard sealing surface An annular groove is made on the lower end surface of the valve disc (2), and a polytetrafluoroethylene sealing ring (16) is fixedly installed in the annular groove. The conical hard sealing surface and the sealing plane that the hard sealing surface and the polytetrafluoroethylene sealing ring (16) cooperate with each other. 2. The high-performance double-sealed bellows globe valve for chlorine gas according to claim 1, characterized in that a metal gasket (6) and a flexible graphite O-ring ( 15) Double sealing structure.