Double-Disc Gate Valve With Adjustable Diversion Hole Sealing

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Solution Overview

Problem

Conventional double-plate gate valves suffer from poor sealing performance at the open position, fragile and non-replaceable disc springs, and adverse effects on sealing performance when one valve plate is not sealed, leading to maintenance challenges and reduced service life.

Innovation Solution

The double-plate gate valve features an adjustable diversion hole structure with adjustable sealing force and face-to-face distance, an external disc spring assembly for easy replacement, and a lower-wedge structure for independent sealing pairs, ensuring reliable two-way sealing and extended service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the conventional diversion hole structure is used, then the valve structure is simple, but the sealing force is insufficient and the seal is not ideal when the valve is at the open position

Engineering Contradiction:
Improvesealing performanceVSAvoidvalve structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The diversion hole assembly is made adjustable with movable positioning holes that allow dynamic repositioning along the guide plate. This enables the sealing surface to adapt to different operational conditions and maintain ideal sealing performance when the valve is open, while the adjustable nature provides flexibility without significantly increasing overall structural complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the fixed geometric parameter of the diversion hole to a variable parameter system. By allowing the positioning holes to be relocated along the guide plate, the sealing geometry can be optimized for different valve positions, improving sealing reliability while maintaining a relatively simple adjustable structure

Inventive Principle:
Principle #35Parameter changes

2Ease of repair

If the disc spring is mounted in the valve chamber, then the valve structure is compact, but the disc spring cannot be replaced online and is fragile under high temperature

Engineering Contradiction:
Improvedisc spring replaceabilityVSAvoidvalve structure complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The disc spring assembly is extracted from the valve chamber and mounted externally on the valve stem. This allows the disc spring to be accessed, inspected, and replaced online without disassembling the valve body, significantly improving ease of repair. The external mounting adds some structural elements but maintains overall compactness while solving the replacement accessibility issue

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A connection structure serves as an intermediary between the external disc spring assembly and the valve stem. This intermediary mechanism transmits the elastic force from the externally mounted disc spring to the valve components, enabling online replacement while maintaining the functional integrity and compact operation of the valve system

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the upper-wedge structure is employed with two valve plates and wedges as movable components, then the valve can achieve closed position sealing, but the seal performance of one valve plate adversely affects the other side

Engineering Contradiction:
Improvetwo-way sealing independenceVSAvoidsealing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing system is segmented into two independent sealing pairs, each with its own valve plate, wedge, and positioning mechanism. This segmentation ensures that the sealing performance of one side is independent of the other, allowing each sealing pair to function autonomously. The segmented structure increases the number of components but guarantees reliable two-way sealing where one failed seal does not compromise the other

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each side of the valve is given its own localized sealing components and adjustment mechanisms. The local quality of each sealing pair can be independently optimized and maintained, ensuring that issues on one side do not propagate to the other side. This localized approach increases component count but ensures independent sealing reliability

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides flexible and reliable sealing, allows for online disc spring replacement, and maintains sealing performance without affecting adjacent seals, resulting in reduced maintenance costs and extended service life.

Implementation Method 1

an energy storage disc spring is provided outside the valve chamber

Methodology Applied
Scientific EffectElastic potential energy: Elasticity

Implementation Method 2

the two valve plates are pushed apart to be pressed tightly on a valve seat by wedges, to form a forced seal

Methodology Applied
Scientific EffectWedge mechanism: Wedge

Implementation Method 3

the valve plates are always in close contact with guide plates, and the valve plates move in the guide plates without clearance, to form a floating seal to prevent the medium from entering the valve chamber

Methodology Applied
Scientific EffectFloating seal:

Data Source

PatentEP3670978B1Double-disc gate valve and use
Publication Date: 2023.10.18 BEIJING AEROSPACE PETROCHEM TECH & EQUIP ENG CORP LTD
  • EP3670978B1 patent drawingFigure 1~2
  • EP3670978B1 patent drawingFigure 3~4
  • EP3670978B1 patent drawingFigure 5~6

AI summary

A double-plate gate valve includes a valve body, a valve cover, a valve stem, a guide plate, a goggle plate assembly, a diversion hole assembly, a disc spring assembly and a valve plate and wedge assembly. The guide plate is nested in a valve chamber formed by the valve body and the valve cover. The goggle plate assembly provides mounting support for the diversion hole assembly and the valve plate and wedge assembly in the valve chamber, the goggle plate assembly is movable along with the diversion hole assembly and the valve plate and wedge assembly in the valve chamber, and floating seals are formed at a contact surface between the diversion hole assembly and the guide plate, and at a contact surface between the valve plate and wedge assembly and the guide plate. The diversion hole assembly is adjustable, that is, a face-to-face distance and a sealing force between a sealing surface of the diversion hole assembly and a sealing surface of the valve body are adjustable, to allow a straight through pipe to be formed and an elastic seal between the diversion hole assembly and a valve seat to be formed in a case that the valve is fully opened. The disc spring assembly is used for overcoming friction forces of the valve plate and wedge assembly and the diversion hole assembly during a closing process of the valve. The valve stem is configured to transmit actuating forces during opening and closing processes of the valve.