Balanced Plug Valve Sealing for Easier High-Pressure Actuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Plug valves used in high-pressure fluid transportation systems, such as those for fracturing oil and gas wells, face challenges with abrasive and corrosive fluids due to high friction, pressure locking, and material costs, as they are difficult to actuate and require durable, heavy materials.
Innovation Solution
The design includes a plug valve with a housing, seat inserts, and a valve body featuring an annular undercut chamber, main seal rings, and plug seal rings, which reduce material usage and weight while providing reliable sealing and easier actuation by balancing pressure loads and minimizing friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If durable, heavy materials are used to withstand abrasive and corrosive fluids at high pressure, then reliability is improved, but weight and material cost increase
Solution Approach 1:
The valve body is divided into multiple segments or sections, allowing the use of different materials in different areas. Critical areas exposed to abrasive and corrosive fluids use durable materials, while non-critical areas use lighter materials, reducing overall weight while maintaining reliability.
Solution Approach 2:
The valve employs composite material construction, combining heavy-duty materials in critical sealing and pressure-bearing areas with lighter materials in structural areas. This selective material application maintains reliability where needed while reducing overall weight and material cost.
2Ease of operation
If conventional plug valve design is used to control flow at high pressure, then flow control is achieved, but actuation difficulty increases due to pressure locking and high friction
Solution Approach 1:
The valve incorporates dynamic sealing elements that can move or adjust during actuation. The seal rings are designed to flex or deform under pressure, maintaining sealing contact despite pressure locking forces, while reducing static friction during the transition from open to closed position.
Solution Approach 2:
The sealing parameters are optimized to change with pressure conditions. The seal ring geometry and material properties are selected to provide adequate sealing force at high pressure while minimizing the breakout torque required for actuation. The seal contact pressure is designed to increase with system pressure, maintaining reliability without requiring excessive actuation force.
Data Source
AI summary
A plug valve for controlling flow through high-pressure fluid flow lines has a valve chamber and a rotatable valve body. The chamber has an undercut. First and second valve seat inserts are mounted in the chamber undercut. The valve body has a midsection, a flow port extending through the midsection, a passage extending between an upper surface and a lower surface of the midsection, an upper valve stem extending from the midsection upper surface, and a lower valve stem extending from the midsection lower surface. The upper surfaces of the valve body exposed to internal fluid pressure and lower surfaces of the valve body exposed to internal fluid pressure have substantially equal surface areas. First and second plug seal rings having substantially equal diameters are mounted, respectively around the upper valve stem and the lower valve stem.