Common Causes of Safety Valve Failure and How to Prevent Them

Incorrect sizing, corrosion, contamination, poor installation, and inadequate maintenance can all affect safety valve performance. Learn the common causes of safety valve failure and practical ways to prevent them.

Pressure Safety Valves · 2026-08-20

Safety valves are critical protection devices used to prevent excessive pressure from damaging industrial equipment. In pressure vessels, pipelines, gas systems, process equipment, storage systems, and pressure-control stations, a safety valve may be the final mechanical barrier against a dangerous overpressure event.

However, installing a safety valve does not automatically guarantee protection. Incorrect sizing, improper installation, corrosion, contamination, poor maintenance, incorrect set pressure, and unsuitable operating conditions can all affect valve performance.

A safety valve that fails to open when required may expose equipment to dangerous overpressure. A valve that opens too early or fails to reseat properly can cause process disruption, product loss, and repeated pressure fluctuations. Understanding these common causes is essential for plant engineers, maintenance teams, EPC contractors, consultants, and operators.

What Causes Safety Valve Failure?

Safety valve failure can originate in valve selection, process conditions, installation, operation, maintenance, or environmental exposure. Some failures are gradual, such as corrosion or spring deterioration. Others result from an incorrect design decision, such as selecting a valve with insufficient relieving capacity.

Incorrect Valve Sizing

One of the most serious mistakes is selecting a safety valve based only on line size or equipment connection. The valve must be sized according to the required relieving capacity under the governing overpressure scenario. An undersized valve may not discharge enough fluid to prevent pressure from continuing to rise, while a significantly oversized valve can experience unstable operation, frequent cycling, or poor reseating.

How to Prevent It

• Perform a proper relief-load calculation for set pressure, relieving pressure, relieving temperature, fluid properties, required mass or volumetric flow, back pressure, and the applicable design code.
• Select a valve with adequate certified capacity for the required application.

Incorrect Set Pressure

The set pressure determines when the valve begins to open. If the setting is too high, protected equipment may reach an unsafe pressure before the valve operates. If it is too low, the valve may open unnecessarily during normal process fluctuations.

Set pressure should be established from the maximum allowable working pressure (MAWP) of the protected equipment and the applicable design code. It should also be evaluated against normal operating pressure to reduce unwanted valve lifting.

Corrosion

Corrosive process fluids or harsh environmental conditions can damage valve bodies, springs, seats, discs, and other internal components. Corrosion can cause leakage, loss of sealing, spring deterioration, reduced flow capacity, and sticking of internal components — particularly in Chemical, Petrochemical, Oil & Gas, Hydrogen, and other demanding applications.

Select materials based on the actual process medium and environmental conditions. Where necessary, use corrosion-resistant materials, suitable trim, protective coatings, or specialised valve construction, and inspect regularly for early signs of corrosion.

Contamination and Deposits

Dirt, rust, scale, process solids, polymer deposits, and other contaminants can accumulate around the seat and disc. Even a small amount of contamination can prevent proper seating and cause continuous leakage; deposits can also restrict the valve flow path.

Maintain clean process piping and consider suitable filtration or upstream protection where appropriate. During maintenance, inspect the seat, disc, nozzle, and internal components, and prevent foreign material from entering the system during installation.

Improper Installation

A correctly selected valve can still perform poorly if it is installed incorrectly. Incorrect orientation, excessive piping loads, undersized inlet piping, poor discharge piping design, excessive pressure drop, and unsupported discharge lines can affect stability, capacity, or reseating.

Follow the manufacturer's installation instructions and applicable engineering standards. Ensure that inlet and outlet piping are properly designed and supported, with sufficient access for inspection and maintenance.

Excessive Back Pressure

Back pressure is the pressure present at the valve outlet, from a discharge header, downstream equipment, or connected systems. Excessive or variable back pressure can affect opening characteristics, relieving capacity, and reseating performance.

Evaluate back pressure during valve selection and system design. For significant back pressure, a balanced bellows safety relief valve or another engineered configuration may be required.

Incorrect Operating Conditions

When normal operating pressure is too close to the set pressure, repeated opening and closing — valve simmering or chattering — can damage internal components and reduce service life. Maintain an appropriate operating margin and keep process controls in good condition to prevent unnecessary pressure fluctuations.

Spring Deterioration

In spring-loaded safety valves, high temperature, corrosion, mechanical fatigue, or unsuitable operating conditions can affect spring performance. A deteriorated spring can result in incorrect set pressure or unreliable operation. Select the correct spring material and temperature range, and include the valve in the plant's periodic inspection, testing, and recalibration programme.

Poor Maintenance and Testing

A safety valve may remain unused for long periods, but it still requires periodic inspection. Without proper maintenance, corrosion, deposits, seat damage, or incorrect set pressure may remain undetected until the valve is needed.

Establish a documented inspection and maintenance programme based on manufacturer recommendations, plant operating conditions, applicable codes and regulations, service severity, and historical valve performance. Testing should verify operating characteristics and set pressure as required.

Key Warning Signs of Safety Valve Problems

• Continuous leakage from the valve
• Unexpected valve lifting
• Repeated opening and closing
• Abnormal noise or vibration
• Corrosion around the valve
• Visible damage
• Pressure instability
• Failure during testing
• Incorrect or missing documentation

Any unusual valve behaviour should be investigated rather than ignored.

How to Prevent Safety Valve Failure

• Select the valve correctly by evaluating pressure, temperature, fluid, relieving capacity, back pressure, materials, connection size, and applicable standards.
• Use certified equipment with the appropriate certifications and documented performance where required.
• Install correctly and ensure inlet and discharge piping are properly designed and supported.
• Inspect regularly for corrosion, leakage, deposits, mechanical damage, and other signs of deterioration.
• Test and recalibrate periodically to confirm that the valve opens at the required set pressure.
• Maintain records of valve specifications, test results, maintenance activities, set pressure, and inspection history.

Why Choose Nirmal Industrial Controls?

Nirmal Industrial Controls Pvt. Ltd. has more than 50 years of engineering expertise since 1973 in pressure control and industrial flow applications. Its portfolio includes pressure regulators, pilot-operated and direct-acting pressure regulators, safety relief valves, tank blanketing systems, pressure reducing stations, metering and regulating stations, City Gate Stations, District Regulating Stations, custody metering skids, heating skids, CNG decompression systems, and complete packaged skids.

This integrated portfolio addresses both pressure regulation and overpressure protection as part of a complete pressure-control solution for Oil & Gas, Chemical, Petrochemical, Pharmaceutical, Hydrogen, CGD, Steel, Power, and Industrial Gas Systems.

Conclusion

Safety valve reliability depends on much more than the valve itself. Correct sizing, set pressure, material selection, installation, back-pressure evaluation, inspection, testing, and maintenance all influence whether the valve will perform when required. A properly selected and maintained safety valve provides an essential layer of protection against abnormal pressure conditions.