Gate Valve Dual Seal Design for High Pressure Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gate valves, particularly resilient wedge gate valves, face challenges in maintaining a consistent liquid or gas tight seal due to production tolerances and debris accumulation, leading to reduced sealing capability under high fluid pressures, especially in larger valves, which complicates operations like double block and bleed processes.
Innovation Solution
The gate valve design incorporates multiple seals on each face, with at least two pairs of seals arranged in a semi-circular or angular profile, allowing for consistent compression and enhanced sealing capabilities, including backup seals to ensure reliable operation under high pressures without the need for additional valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single seal is provided on each sealing face, then the device complexity is reduced, but the reliability of sealing deteriorates under high fluid pressures
Solution Approach 1:
The gate is divided into multiple sealing sections, with at least two seals provided on each sealing face. This segmentation allows the sealing function to be distributed across multiple elements, improving overall reliability while managing complexity through functional division
Solution Approach 2:
Backup seals are provided in addition to primary seals. These backup seals remain inactive during normal operation but activate automatically if the primary seal fails, providing beforehand protection against sealing failure under high pressures
2Ease of operation
If the gate is allowed to move freely under fluid pressure, then the ease of operation is improved, but the sealing performance deteriorates due to reduced compression on upstream face
Solution Approach 1:
Different parts of the gate have different properties: the first and second seals on the upstream face are designed with specific geometries and materials optimized for high-pressure sealing, while the third and fourth seals on the downstream face are optimized for their respective conditions. This local optimization allows the gate to move freely while maintaining sealing performance at each location
3Ease of manufacture
If resiliently deformable material is used on the gate, then the manufacturing precision requirements are reduced, but the sealing consistency deteriorates due to varying material thicknesses
Solution Approach 1:
The sealing material thickness is varied intentionally across different parts of the gate. The first and second seals have different thicknesses from the third and fourth seals, with each thickness optimized for its specific sealing location and pressure conditions. This parameter variation compensates for manufacturing tolerances while maintaining consistent sealing performance
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
This design significantly improves sealing performance across the entire periphery, enabling the valve to handle higher fluid pressures with reduced leakage and operational torque, enhancing safety and reducing installation costs by eliminating the need for dual valves in double block and bleed operations.
Implementation Method 1
the wedge shaped gate is coated with or possibly formed from, a resiliently deformable material such as a rubber material. This resiliently deformable material seals against the valve seat cast in the valve body and can adapt to some extent to imperfections in the profile of the valve seat, and in the gate valve itself, thus providing an improved seal as long as sufficient compression of the resilient material is maintained
Implementation Method 2
such that the compression of all parts of the seal is substantially constant
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A gate valve (1) is disclosed for mounting in a pipeline, the gate valve (1) comprising a valve body (3) and a gate (21) mounted in the valve body (3) so as to be movable between an open position, and a closed position where a valve opening (7) formed in the valve body (3) is closed by the gate (21). The gate (21) comprises two opposed faces (24, 25) spaced from the transverse plane (22) of the gate (21), at least one face (24) being provided with at least two seals (41, 43) that each extend around the face (24) one seal being located within the periphery of the other such that both seals (41, 43), when the gate (21) is in the closed position, seal against a seat (5) of the valve body (3) to seal against the pressure of fluid acting on the gate (21) in use. A gate (21) is disclosed having four seals (41, 43, 45, 47) in total, two (41, 43) on the upstream gate face (24) and two (45, 47) on the downstream gate face (25).