阅读说明：本技术 一种可在线更换密封副的三偏心金属密封蝶阀结构 (Three-eccentric metal seal butterfly valve structure with online replaceable seal pair ) 是由 张清双 茅岭峰 于 2019-10-23 设计创作，主要内容包括：一种可在线更换密封副的三偏心金属密封蝶阀结构,包括阀体、限位销a、三开环、锁紧螺母、螺钉a、阀座密封圈、多层次密封圈、限位销b、蝶板、压板、螺钉b,阀体内设置有阀座密封圈,阀座密封圈通过三开环、锁紧螺母、螺钉a固定于阀体内,阀座密封圈与阀体间设置有限位销a,限位销a对阀座密封圈进行限位,蝶板上设置有多层次密封圈,多层次密封圈通过压板、螺钉b压紧并固定在蝶板上,蝶板、多层次密封圈和压板通过限位销b进行位置固定,阀体上设置有检修仓口。本发明的有益效果是,解决了原三偏心结构无法在线更换密封副的缺点,在线更换时通过设置限位销,确定了密封副位置,降低了蝶阀的泄漏风险,确保LNG接收站的安全有效运行。(The utility model provides a can change sealed vice three off-centre metal seal butterfly valve structure on line, which comprises a valve body, spacer pin an, three ring-opening, lock nut, screw a, the valve seat sealing washer, multi-level sealing washer, spacer pin b, the butterfly plate, a pressing plate, screw b, be provided with the valve seat sealing washer in the valve body, the valve seat sealing washer is through three ring-opening, lock nut, screw a is fixed in the valve body, be provided with spacer pin an between valve seat sealing washer and valve body, spacer pin a carries out spacingly to the valve seat sealing washer, be provided with multi-level sealing washer on the butterfly plate, multi-level sealing washer passes through the clamp plate, screw b compresses tightly and fixes on the butterfly plate, multi-level sealing washer and. The invention has the advantages that the defect that the original triple eccentric structure cannot replace the sealing pair on line is overcome, the position of the sealing pair is determined by arranging the limiting pin during on-line replacement, the leakage risk of the butterfly valve is reduced, and the safe and effective operation of the LNG receiving station is ensured.)

1. The utility model provides a can change sealed vice three off-centre metal seal butterfly valve structure on line, includes valve body, spacer pin an, three ring-opening, lock nut, screw a, valve seat sealing washer, multi-level sealing washer, spacer pin b, butterfly plate, clamp plate, screw b, its characterized in that, be provided with valve seat sealing washer in the valve body, valve seat sealing washer is fixed in the valve body through three ring-opening, lock nut, screw a, be provided with spacer pin an between valve seat sealing washer and valve body, spacer pin a carries on spacingly to valve seat sealing washer, be provided with multi-level sealing washer on the butterfly plate, multi-level sealing washer compresses tightly and fixes on the butterfly plate through clamp plate, screw b, butterfly plate, multi-level sealing washer and clamp plate carry out the rigidity through spacer pin b, be provided with on the valve body and overhaul.

2. The structure of claim 1, wherein the multi-layer sealing ring is made of flexible graphite +304 stainless steel gasket.

Technical Field

The invention relates to a three-eccentric metal sealing butterfly valve, in particular to an ultra-low temperature butterfly valve for LNG projects and other ultra-low temperature working conditions.

Background

At present, a butterfly valve which is commonly used and can replace a sealing pair on line is often of a double-eccentric structure, a sealing ring of the butterfly valve is made of copper alloy, but the butterfly valve is not suitable for the ultralow-temperature working condition of sulfur-containing LNG, and sulfide can corrode copper to seriously affect the sealing performance of the butterfly valve. Meanwhile, the butterfly valve with the double eccentric structure has more defects and is not suitable for LNG working conditions, the sealing principle of the butterfly valve belongs to position sealing, the sealing surface of the butterfly plate and the valve seat is in line contact, sealing is realized by elastic deformation caused by extruding the valve seat by the butterfly plate, the requirement on the closing position is very high, and particularly, the metal valve seat has the defects of low pressure bearing capacity, large leakage amount and the like. And the sealing surface of the common triple eccentric structure is in an oblique cone type, so that the sealing point can not be directly aligned due to no positioning when the valve seat sealing ring is installed, and the valve sealing pair can not be directly replaced when the phenomenon that the sealing is impossible due to the fact that the sealing pair is not matched after installation occurs.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides a three-eccentric metal seal butterfly valve structure with a seal pair capable of being replaced online.

The invention has the technical scheme that the three-eccentric metal seal butterfly valve structure with the online replaceable seal pair comprises a valve body, a limiting pin a, three open rings, a locking nut, a screw a, a valve seat seal ring, a multi-layer seal ring, a limiting pin b, a butterfly plate, a pressing plate and a screw b, wherein the valve seat seal ring is arranged in the valve body, the valve seat seal ring is fixed in the valve body through the three open rings, the locking nut and the screw a, the limiting pin a is arranged between the valve seat seal ring and the valve body, the limiting pin a limits the valve seat seal ring, the butterfly plate is provided with the multi-layer seal ring, the multi-layer seal ring is pressed and fixed on the butterfly plate through the pressing plate and the screw b, the butterfly plate, the multi-layer seal ring and the pressing.

Furthermore, the multi-layer sealing ring is composed of a flexible graphite +304 stainless steel gasket.

The invention has the advantages that the defect that the original triple eccentric structure cannot replace the sealing pair on line is overcome, the position of the sealing pair is determined by arranging the limiting pin during on-line replacement, the leakage risk of the butterfly valve is reduced, and the safe and effective operation of the LNG receiving station is ensured.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a partial enlarged view of a1 in fig. 1.

In the figure: 1. a valve body; 2. a limiting pin a; 3. opening a ring; 4. locking the nut; 5. a screw a; 6. a valve seat sealing ring; 7. a multi-layer sealing ring; 8. a limiting pin b; 9. a butterfly plate; 10. pressing a plate; 11. a screw b; 12. and (5) overhauling the bin opening.

Detailed Description

As shown in fig. 1-2, a triple eccentric metal seal butterfly valve structure with an online replaceable seal pair comprises a valve body 1, a limit pin a2, a three-opening ring 3, a lock nut 4, a screw a5, a valve seat seal ring 6, a multi-layer seal ring 7, a limit pin b8, a butterfly plate 9, a pressure plate 10 and a screw b11, wherein the valve seat seal ring 6 is arranged in the valve body 1, the valve seat seal ring 6 is fixed in the valve body 1 through the three-opening ring 3, the lock nut 4 and the screw a5, the three-opening ring 3 and the screw a5 can be locked through the lock nut 4, the limit pin a2 is arranged between the valve seat seal ring and the valve body, the limit pin a2 limits the valve seat seal ring 6, the valve seat seal ring 6 can be installed only by aligning with the limit pin a2 when being installed, the position is completely fixed, a pin hole on the valve body 1 and a pin, the butterfly plate 9 is provided with a multi-layer sealing ring 7, the multi-layer sealing ring 7 is composed of flexible graphite and 304 stainless steel pads, the multi-layer sealing ring 7 is pressed and fixed on the butterfly plate 9 through a pressure plate 10 and a screw b8, the butterfly plate 9, the multi-layer sealing ring 7 and the pressure plate 10 are fixed in position through a limit pin b11, the valve body 1 is provided with an inspection bin opening 12, a sealing pair can be replaced on line through the inspection bin opening 12,

the replacing steps are as follows:

releasing pressure in the valve, loosening a cover plate nut of the overhaul bin port 12, and opening a cover plate of the overhaul bin port 12;

step two, loosening the screw a5 through the overhaul bin opening 12, and taking out the three-open ring 3;

step three, half opening the butterfly plate 9, taking out the valve seat sealing ring 6, and taking out the limit pin a2 between the valve seat sealing ring 6 and the valve body 1;

step four, the butterfly plate 9 is in a closed position, the screw b11 is loosened, and the pressure plate 10 is taken out;

step five, taking out the limiting pin b8 and taking out the multi-layer sealing ring 7;

sixthly, replacing the valve seat sealing ring 6 and the multi-layer sealing ring 7 on line;

step seven, mounting the new multi-layer sealing ring 7 on the butterfly plate, aligning with the pin hole of the butterfly plate 9, and inserting a limit pin b 8;

step eight, mounting the pressure plate 10, and fixing the pressure plate 10 through a screw b 11;

step nine, opening the butterfly plate 9 to a half-open position, and installing a limit pin a2 into a pin hole of the valve body 1;

installing a new valve seat sealing ring 6, and installing a pin hole on the valve seat sealing ring 6 in alignment with a limit pin a2 on the valve body 1;

step eleven, installing the three-open ring 3 and the screw a5, finely adjusting the position of the valve seat sealing ring 6 by tightening the screw a5, locking the screw a5 by using the locking nut 5 after the adjustment is finished, and closing the butterfly plate 9.

The technical scheme overcomes the defect that the original triple-eccentric structure cannot replace the sealing pair on line, and the position of the sealing pair is determined by the method of arranging the limiting pin during on-line replacement, so that the leakage risk of the butterfly valve is reduced, and the safe and effective operation of the LNG receiving station is ensured.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.