Hardened Valve Plug Assembly for Wear Without Carbide Cracking

Solution Overview

Problem

Control valves in severe service applications, such as those used in the petrochemical industry, face rapid wear and damage from erosive and corrosive process fluids, leading to reduced operating life and potential leakage due to the use of carbide materials, which are brittle and prone to cracking under high actuator thrust forces and vibrations.

Innovation Solution

A four-piece valve plug assembly comprising a plug holder, spacer, sleeve, and carbide tip, where the sleeve is composed of a softer material to absorb deformation and vibrations, and a split coupler design with differential thermal expansion rates to maintain retention of the carbide tip, along with a segregated throttling and shutoff configuration, and an anti-coking wiper to prevent material buildup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If carbide materials are used for valve plugs in severe service applications, then wear resistance is improved, but brittleness increases leading to cracking under high actuator thrust forces and vibrations

Engineering Contradiction:

Improvewear resistanceVSAvoidcracking resistance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The valve plug is divided into multiple segments: a carbide tip insert for wear resistance, a metallic body for structural strength, and a metallic sleeve for retention. This segmentation allows each material to perform its optimal function without the weaknesses of the others.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The valve plug combines different materials (carbide, stainless steel) to create a composite structure that exhibits both the wear resistance of carbide and the ductility and toughness of metallic materials, eliminating the brittleness problem of pure carbide plugs.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If carbide valve plugs are used, then erosion resistance is improved, but susceptibility to damage from vibrations and thrust forces increases

Engineering Contradiction:

Improveerosion resistanceVSAvoiddamage resistance

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The valve plug is divided into multiple segments: a carbide tip insert for wear resistance, a metallic body for structural strength, and a metallic sleeve for retention. This segmentation allows each material to perform its optimal function without the weaknesses of the others.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The carbide material is applied locally only where erosion and wear occur (at the tip), while the body and retention mechanisms use ductile metallic materials that can absorb vibrations and thrust forces without cracking.

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If a four-piece assembly design is used with differential thermal expansion rates, then retention of carbide tip is maintained, but device complexity increases

Engineering Contradiction:

Improveretention stabilityVSAvoidassembly complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The metallic components (body and sleeve) are designed with thermal expansion characteristics that maintain compression on the carbide tip across a range of temperatures. The differential expansion between materials is accounted for in the design to ensure continuous retention.

Inventive Principle:

Principle #37Thermal expansion

Solution Approach 2:

The valve plug is divided into multiple segments: a carbide tip insert for wear resistance, a metallic body for structural strength, and a metallic sleeve for retention. This segmentation allows each material to perform its optimal function without the weaknesses of the others.

Inventive Principle:

Principle #1Segmentation

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

Enhances the operating life and reliability of control valves by reducing wear, preventing leakage, and improving responsiveness through a combination of materials and design features that mitigate cracking and enhance sealing performance under severe conditions.

Implementation Method 1

a split coupler design with differential thermal expansion rates to maintain retention of the carbide tip

Methodology Applied

Scientific EffectDifferential thermal expansion: Thermal Expansion

Implementation Method 2

the sleeve is composed of a softer material to absorb deformation and vibrations

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the sleeve is composed of a softer material to absorb deformation and vibrations

Methodology Applied

Scientific EffectVibration damping: Damping

Data Source

PatentUS12422043B2Valve plugs including hardened tips

Publication Date: 2025.09.23 FISHER CONTROLS INT LLC

AI summary

Valve plugs including hardened tips are disclosed herein. An example apparatus disclosed herein includes a plug holder, a sleeve coupled to the plug holder, the sleeve including a lip, a valve plug tip retained by the lip, and a spacer disposed between the plug holder and the tip, the sleeve surrounding the spacer.