Gate Valve Sealing With Rectangular Cavity and U-Shaped Seals
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Solution Overview
Problem
Existing gate valve assemblies are heavy and bulky, requiring larger seats and more material for the same size throughbore, limiting their use in various oilfield applications due to weight, size, and sealing issues across different temperatures, pressures, and fluid types, and lack flexibility for bidirectional sealing options.
Innovation Solution
A gate valve design featuring a body cavity with a combination of circular and rectangular cross-sections, utilizing non-elastomeric U-shaped seals for bidirectional sealing with downstream backup, and a skirt assembly to prevent contaminants, allowing for reduced weight, size, and versatility across different conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a round body cavity is used, then the valve body requires more material and is heavier, but the gate and seats can be larger for better sealing
Solution Approach 1:
The body cavity uses an asymmetric rectangular cross-section instead of a traditional round cross-section. This asymmetric shape reduces the material required for the valve body, decreasing weight by approximately 32%, while still providing adequate space for the gate and seats to function properly.
Solution Approach 2:
The invention changes the geometric parameters of the body cavity from a round cross-section to a rectangular cross-section with specific dimensions (e.g., 4.5 inches by 5.5 inches). This parameter change optimizes the balance between weight reduction and sealing effectiveness, allowing slimmer gates and seats to achieve reliable sealing.
2Reliability
If larger seats are used, then sealing is improved, but the valve size and weight increase
Solution Approach 1:
The rectangular body cavity creates an asymmetric space that allows for more efficient packing of the gate and seats. This asymmetric geometry enables the use of slimmer, more compact sealing components that achieve effective sealing without requiring large seat areas, thus reducing the overall valve body dimensions.
Solution Approach 2:
By changing the body cavity geometry to rectangular, the invention alters the spatial parameters available for seat placement. This enables the design of compact seats with reduced dimensions (e.g., 1.6 inches width) that maintain sealing reliability while minimizing the valve body area and overall size.
3Adaptability or versatility
If traditional elastomeric seals are used, then sealing is effective, but the valve cannot operate across all temperature and pressure ranges
Solution Approach 1:
The invention changes the material parameter of the seals from elastomeric to non-elastomeric materials (such as PTFE or other high-performance polymers). This material parameter change enables the seals to operate reliably across extreme temperature ranges (-50°F to 350°F) and high pressures (up to 20,000 psi) without degrading, while maintaining sealing effectiveness through the combination of multiple seal types (U-shaped seals, support rings, retainer rings).
Solution Approach 2:
The sealing system uses composite material construction with non-elastomeric seal materials combined with metal springs and support structures. This composite approach provides both the flexibility needed for sealing and the thermal/pressure resistance required for oilfield applications, achieving versatility across all operating conditions while maintaining reliability.
4Adaptability or versatility
If the valve is designed for bidirectional sealing, then versatility is improved, but the number of seals and parts increases
Solution Approach 1:
The valve design incorporates universal sealing capabilities in both upstream and downstream directions using the same basic seal components (U-shaped seals, support rings, retainer rings). This multi-functional sealing system allows the valve to provide bidirectional sealing without requiring entirely separate seal sets for each direction, thereby reducing the overall number of components compared to traditional bidirectional designs while maintaining versatility.
Data Source
AI summary
The present invention discloses a gate valve with a first side and a second side relative the throughbore. A circular body cavity is on the first side and a rectangular body cavity on the second side and a portion of the first side whereby the gate is operable to move up and down within the body cavities. Due to the rectangular body cavity, the seats are slimmer than the gate. A skirt assembly is used which is inserted over the gate to cover the gate opening when the gate is moved to the closed position to prevent debris and other contaminants from entering the body cavity. Four U-shaped seals are mounted to provide that the gate valve is a bidirectional gate valve with upstream sealing having back up downstream sealing in case an upstream seal fails.