Understanding Valve Leakage: Causes, Solutions, and Preventive Measures

Valve leakage is one of the most common problems in industrial piping systems. Whether used in oil and gas, chemical processing, water treatment, or power generation, faulty valves can lead to costly fluid loss, environmental contamination, equipment damage, and even serious safety risks.

This article explores the main causes of valve leakage, categorized by internal and external leakage, and offers practical solutions and preventive strategies to help plant engineers, maintenance teams, and procurement professionals address the issue effectively.

What Is Valve Leakage?

Valve leakage refers to the unwanted flow of fluid either through the valve when it should be closed (internal leakage) or from the valve body or its connections to the environment (external leakage). Both types can compromise system integrity if left unresolved.

Internal Valve Leakage: Common Causes & Fixes

Internal leakage occurs when the valve fails to fully shut off the flow.

Common Causes:

1.Damaged sealing surface

Erosion by solid particles in the medium (e.g. sand, welding slag)

Corrosion from aggressive chemicals (e.g. acids, chloride ions)

2.Worn or aged sealing materials

Rubber or PTFE soft seals may crack or harden over time

Metal-to-metal seals wear out from frequent use

3.Valve not fully closed

Incomplete operation due to insufficient torque or actuator malfunction

Valve stem or drive mechanism blockage

4.Foreign objects lodged between valve seat and disc

Rust, scale, or debris can prevent full closure

Solutions:

• Inspect and clean sealing surfaces
• Regrind or replace damaged seals
• Ensure full closure via manual or actuator adjustment
• Flush pipeline and install upstream filters if needed
• Use corrosion-resistant materials (e.g., stainless steel, lined valves)

External Valve Leakage: Types, Causes & Remedies

External leakage means fluid escapes from the valve body, stem, or connection points.

1.Leakage at the stem (stuffing box/gland leakage)

Causes:

Worn or aged packing materials (e.g., graphite, PTFE)

Loose gland bolts

Scratched or corroded valve stem

Fixes:

Tighten or replace packing (avoid overtightening)

Repair or replace damaged stem

2.Leakage at valve body or flanged joints

Causes:

Loose flange bolts or insufficient preload

Gasket failure (wrong type or damaged)

Valve body casting defects (e.g., sand holes, cracks)

Fixes:

Retighten bolts using a diagonal torque pattern

Replace gaskets with appropriate materials (e.g., spiral wound or metal gaskets for high temperature)

Repair or replace defective valve body

3.Leakage at bonnet or weld seams

Causes:

Poor welding quality or casting flaws

Thermal fatigue cracks due to pressure/temperature cycling

Fixes:

Shut down and replace the valve

Evaluate the weld or casting; repair only if it’s safe and certified

Preventive Maintenance: Your Best Investment

Proactive valve maintenance can prevent most leakage issues before they occur.

Essential Measures:

Routine inspection of seals, packing, and stem

Avoid aggressive operation, especially over-torqueing or rapid closing

Match the valve type and material to the media and temperature (e.g., ceramic-lined valves for corrosive fluids)

Install strainers or filters upstream of sensitive valves

Always pressure-test new valves before commissioning

Emergency Handling for Leakage

When leakage occurs and shutdown is not immediately possible:

Use temporary sealants such as epoxy or metallic repair compounds

Apply external leak clamps or wrap systems for flange leaks

Isolate and depressurize systems for hazardous fluids like toxic or flammable media

Consult professional valve repair services for permanent solutions

Conclusion: Solve the Root, Not Just the Symptoms

Valve leakage is not just a maintenance issue—it’s a performance and safety risk. By understanding the specific cause of leakage—whether internal or external—you can adopt targeted solutions and build a more resilient, cost-efficient fluid control system.

At Haihao Group, we not only manufacture a wide range of industrial valves but also support our customers with failure analysis, material selection guidance, and custom sealing solutions for all kinds of working conditions.

Need help diagnosing or solving a valve leakage issue? Contact our technical support team today! Email:sales@haihaogroup.com