Floating Seat Plate Valve Sealing Under Thermal Cycling
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Solution Overview
Problem
The existing coke drum deheading valves experience thermal cycling issues due to extreme temperature variations, leading to weakened components and leaks, and require high steam pressure to maintain seals, increasing operational costs.
Innovation Solution
A floating seat plate that articulates with the gate to maintain a seal despite thermal expansion, isolating the valve body from process fluids and reducing steam leakage by using a bias system and INCONEL® bellows to accommodate thermal deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tight tolerances are used between seat and gate to form a seal, then sealing performance is improved, but the force required to slide the gate increases
Solution Approach 1:
The seat is designed to float and articulate dynamically rather than being fixed, allowing it to adapt its position and orientation to maintain sealing contact with the gate under varying thermal and pressure conditions. This dynamic adjustment reduces the force required to operate the gate while maintaining tight sealing performance.
Solution Approach 2:
The floating seat design allows for changes in the seat's position and orientation parameters in response to thermal expansion and pressure variations. By allowing the seat to move and articulate, the system adapts to parameter changes caused by thermal cycling, maintaining sealing effectiveness without requiring excessive operating force.
2Reliability
If steam is pressurized to maintain seal integrity, then sealing reliability is improved, but steam consumption and operational costs increase
Solution Approach 1:
The floating seat design enables the sealing system to self-adjust and maintain integrity through its own mechanical properties (浮力 and articulation) rather than requiring continuous external steam pressure. The seat automatically positions itself to maintain sealing contact, reducing or eliminating the need for pressurized steam to maintain seal integrity.
3Ease of manufacture
If fixed seat design is used, then manufacturing simplicity is improved, but adaptability to thermal deformation decreases
Solution Approach 1:
The seat is designed with floating and articulating capabilities, transforming it from a static component to a dynamic one that can adapt to thermal deformations. This allows the seat to move and reposition itself in response to thermal expansion and contraction of the gate, maintaining sealing effectiveness throughout thermal cycling without complex manufacturing.
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 enhances the longevity of valve components by preventing leaks and reducing steam consumption, thus lowering operational costs and maintaining effective sealing under thermal cycling.
Implementation Method 1
a bias system configured to bias the seat plate against the gate
Implementation Method 2
using a bias system and INCONEL® bellows to accommodate thermal deformation
Data Source
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AI summary
A seat plate which maintains constant contact and load against the gate to keep sealing surfaces protected is disclosed. The seat plate has a dynamic seat function ie live-loaded to follow the gate surface during stroking and high temperature changes. The valve maintains a positive barrier between body steam chamber and process fluid through port. The valve uses an extended seat plates to maintain constant contact with gate in all positions such that all process is captured and not allowed to enter body chamber. The seat plate allows for sufficient axial seat travel upstream and downstream to balance sealing load on both sides of gate. In addition, an axial hard stop on each seat allowing upstream seat to maintain sealing contact with gate