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What Causes Valve Seat Damage, and How to Prevent It

If you’re dealing with valve seat damage, it’s ideal to know how to prevent this from happening again. Read this helpful guide.

What Causes Valve Seat Damage, and How to Prevent It - KB Delta

Valves are vital components that help control or regulate the flow of fluids by rhythmically closing, opening, or creating particle obstructions to numerous passageways. They are widely employed in industrial processes, including:


  • Sewage and water processing
  • Gas and petroleum
  • Mining
  • Plastic and chemical manufacturing
  • Processing of oil
  • Power generation, etc.


Valves come in seals that different engines use to control valve lubrication and oil consumption. But a valve will not function effectively without a valve seat.

The valve seat refers to the surface within the body of a valve that comes in direct contact with the disk. It is the moveable component that allows and restricts flow through the valve.

Valve seats must be compatible with the type of valves within an engine. These seats are induction-hardened and integral for wear resistance, like most cast iron heads.


The Role of Valve Seats

Valve seats play 2 crucial roles, which are as follows:


  • Airtightness Retention

The valve seat tightly holds precisely when the valve is seated, thereby preventing the leaking of combustion gas or compressed gas into the manifold between the valve seat itself and the valve.


  • Heat Conduction

During operations, high-temperature combustion gas and heating release heat from the valve. This is where the other crucial role of valve seats comes in at it involves minimizing cylinder head and vale friction simultaneously.

Valve seats also carry out the following functions:


  1. Maintain the strength of the seal when the valve has been mounted. The integrity and quality of valve seat rings play a crucial role in this area.
  2. Minimize wear resistance since the entire valve seat must be capable of withstanding the pressure of high loads and high heat.


Valve seats must display agreeable characteristics, including the smooth operation between the seat itself and the partner valve. It also helps keep work processes prolonged in order to ensure the operation is maintained at a reasonable cost.


Failing Valves

Valves may help ensure proper operation and safety, but they are delicate devices prone to failure.

Several factors are responsible for causing valves to fail, and they include:


  • Debris within the pipeline
  • Operating perpetually in excessively high-temperature conditions
  • Worn seat seals and elastomers
  • Inappropriate installation of the valve, maintenance, and assembly.


So, what are the symptoms that reveal a failing valve? One of the first signs of a failing valve is the warning signs it emits. Failing valves will start vibrating and sometimes lose some internal parts as the problem aggravates.

Another notable symptom of a failing valve includes significant component damage and wear as well as reverse flow.

A valve that is about to fail may also let out some noises. This situation – known as ‘Water hammer’ – occurs when the disc slams into the valve seat.

Water hammers can bring about severe damage as pipelines rupture. The best way to combat this problem is by installing a faster-closing valve. The check valve will efficiently prevent sudden pressure surges.

Another notable symptom of a failing valve is when it starts sticking and leaking as it breaks down. Sticking is a situation that occurs when valves are stuck in a specific position. It is caused by the introduction of debris into the disc and body bore. Leaks originate from a damaged disk or seat or contaminants within the pipeline.


Top Reasons Valves Fail

By now, you already know that the importance of valve seats cannot be overstated. Valve failure can be time-consuming and costly, leading to severe downtimes.

Here are some of the reasons why valves fail:


  • Faulty Seat Design

The most critical component of most valves is the valve seat. If the valve seat is faulty, the valve will not work.

The consequences of a faulty seat design include shortened life span, minimal leakage, and catastrophic failure. This can have life-threatening and explosive effects, depending considerably on the environment and media.


  • Inferior Soft Seat Carrier Design

Many valves utilize soft seats that use outer metallic seat carriers and valve seat inserts molded or pressed into them. This type of design has several benefits, but the wrong design can cause valve failure.


  • Substandard Material Choice

Valve seats are constructed using a wide variety of plastic materials. The wrong material choice for manufacturing valve seats can bring about unexpected failure.

This is because different operating conditions and applications require different valve seat materials. This is why it is crucial to study the physical properties of all available plastic materials before choosing the type suitable for a specific operation.


  • Excessive Torque/Friction

There is friction between the ball and seats, directly affecting the torque needed to turn the ball valve. Minimal seal force – within a ball valve – is required in order to prevent leakage.

But excessive circumferential seal force can bring about accelerated wear. It can also lead to an increase in the torque requirements. When temperature increases, the pressure between the ball and seat increases accordingly, resulting in greater friction.

In extreme cases, the valve may become locked in a specific position, i.e., it cannot be opened or closed. This brings about the mechanical failure of the seat as it gets torn into pieces within the valve. Once again, the selection of a choice material is crucial.


  • Cold Flow

PTFE (polytetrafluoroethylene) is one of the commonly-used materials for valve seats. This material is inert to nearly all known chemicals, has excellent sealing properties, and has a wide range of temperature applications.

Nevertheless, PTFE has a notable downside: its cold-flow resistance. The cold flow of the seat material during use and cycling can bring about a slow deterioration in the performance of valves. This can cause severe valve failure.

This is why choosing a filled grade PTFE that is less vulnerable to cold flow for seat design is essential.


The Importance of Maintenance and Valve Check

Maintenance and valve check is crucial. Any super-tiny damage that appears within the sealing surface can cause untold and widespread damage within the sealing surface within a short period.

Maintenance is preventive and helps minimize downtimes and costly repairs. It makes it easier to detect faulty components that require immediate replacement to prevent additional damage or wear and tear.

This is why regularly conducting valve checks, and maintenance should not be skimped for any reason, especially if the operation occurs in life-threatening or explosive environments.



The importance of well-designed, high-quality valve seats cannot be overstated. Failure can be grossly inefficient and costly, leading to severe downtimes.

This is why regular maintenance is crucial as it helps to minimize valve seat damage, especially when symptoms are observed. Any early sign of valve failure can be addressed instantly, eliminating the need for downtimes and costly repairs.



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