Multi-valve Seat Seal Assembly for Gate Valves
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Solution Overview
Problem
Existing gate valves in oil and gas fields face challenges with seal longevity, especially in corrosive environments and high temperatures, and metal seals suffer from premature wear and insufficient sealing capacity.
Innovation Solution
A multi-valve seat seal assembly is introduced, comprising a primary metal seat seal with a dynamic leg and polymeric coating, a secondary seat seal with an anti-extrusion ring, and a tertiary seat seal for redundancy, along with a sand excluder to prevent particle ingress, enhancing sealing performance and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If metal seals are used to withstand high temperatures and pressures, then temperature and pressure resistance is improved, but premature wear and damage to sealing surfaces occur
Solution Approach 1:
The invention uses a composite sealing structure combining metal seat seals with polymeric coatings. The metal provides structural integrity and temperature/pressure resistance, while the polymeric coating reduces friction and wear. This composite approach allows the seal to withstand high temperatures and pressures without premature wear, resolving the contradiction between temperature resistance and seal longevity.
Solution Approach 2:
The invention changes the surface properties of the metal seal by applying polymeric coatings with specific friction and wear characteristics. This parameter change allows the sealing surface to maintain low friction and wear resistance under high temperature and pressure conditions, preventing premature wear while maintaining temperature resistance.
2Reliability
If elastomeric seals are used for sealing, then sealing capacity is improved, but longevity in corrosive environments and high temperatures deteriorates
Solution Approach 1:
The invention creates a composite seal system where polymeric coatings are applied to metal seat seals. The polymeric material provides excellent sealing capacity similar to elastomeric seals, while the metal substrate provides longevity and resistance to corrosive environments and high temperatures. This composite structure combines the advantages of both materials.
Solution Approach 2:
The polymeric coating acts as an intermediary layer between the metal seal and the corrosive environment. It provides the sealing function of elastomeric materials while protecting the metal substrate from corrosion and thermal degradation, thereby extending seal longevity in harsh conditions.
3Device complexity
If single seal design is used to simplify structure, then device complexity is reduced, but sealing reliability under varying conditions deteriorates
Solution Approach 1:
The invention segments the seal into multiple functional components: a metal seat seal structure and a polymeric coating layer. Each segment performs a specific function - the metal provides structural support and temperature/pressure resistance, while the polymeric coating provides sealing and wear protection. This segmentation improves sealing reliability without significantly increasing overall complexity.
Solution Approach 2:
The multi-component seal design creates a universal sealing solution that can handle varying operating conditions including different temperatures, pressures, and corrosive environments. The combination of materials provides multi-functionality, making the seal reliable across a wide range of conditions while maintaining a relatively simple overall structure.
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 multi-valve seat seal assembly provides improved sealing integrity and longevity, maintaining effective sealing under high pressures and temperatures, and preventing sand and debris entry, thus reducing leakage and wear.
Implementation Method 1
The first leg is also configured to seal against the valve body, and may have a polymeric coating
Implementation Method 2
The sand excluder is positioned between the seat ring and the valve body adjacent the flow passageway, and has a spring and an excluding arm
Data Source
AI summary
A gate valve for use in oil field applications and including a seat seal assembly. The seat seal assembly includes primary, secondary, and tertiary seals for sealing the space between the seat rings and the valve body. The provision of multiple seals in the seat seal assembly provides redundancy that allows for maintenance of the seal between the components even if one or two of the individual seals fail.