Are Your Safety Valves Safe?

There was a recent article in Empowering Valves that outlined and defined various valves that are used in critical applications.

The human heart has four valves that control blood flow through the body.  Industrial valves act in a similar manner and control how fluid flows through a pipe or a duct.  There are many different types of valves used for various applications and it is extremely important that the valve is made of the correct materials.  The article explained how valves may need to stand high pressure or may have caustic fluids flowing through them that will eventually corrode the material.  If a pressure relief safety valve blows on a steam boiler, there could be injuries to employees. Leaks in safety valves used in gas or vapor situations could cause environmental hazards.  In the oil and gas industry, there are valves not only throughout the pipelines, but also on storage tanks to control fugitive emission losses that can result from handling flammable and hazardous petroleum products that produce vapor.

The author explained that:

Liquids and other media flowing through valves during critical operating conditions can be affected by a number of hazards…. The symptoms of valves that may be failing include an increase in noise emission, valve and pipe component erosion, or mechanical vibration in the valves and the connected pipelines. Under many critical applications, neglecting these signs can result in negative outcomes on plant performance, the costs of ownership, fugitive emissions, and even serious safety hazards. This why many safety valves are required to be made to ASME, ANSI, and/or API standards.

In a previous article, we wrote about an effort to address the flow-accelerated corrosion, or FAC issue, in nuclear and fossil-fuel power plants.  Calculation methods of piping wall thinning due to erosion-corrosion were reviewed and benchmarked to develop maintenance guidelines. FAC occurs when carbon steel piping and components are degraded by flowing water or steam water with low-dissolved oxygen. As the water flows against the carbon steel material, the stable surface oxide layer (typically Fe3O4) is dissolved into the flowing stream – thinning the walls of piping over time and causing them to rupture. (See this infographic outlining 10 Reasons To Use Handheld XRF On Oil & Gas Pipelines.)

You Need to Verify You Have The Right Metal for the Job

Industries that use safety valves in their operations must remember, however, that valves are affected in the same way as pipes.  Fluids are not only passing through them but there is also pressure on the materials when safety valves are open and closed, which could lead to greater or more rapid corrosion.  So verifying metal alloys is essential to manufacturing quality assurance. If you are the one producing the valves, you need to ensure that the products that go out the door match the customer’s specifications and meet industry standards.  Is the metal or alloy correct?  Are you sure?  Your reputation and brand depend on it.  If you are the one using the valves, you better make certain that the incoming product matches your specifications.  Lives could depend on it.  And if your company relies on those valves to keep operations running smoothly, you better have a maintenance schedule in place to make sure that there has been no degradation over time.

Portable x-ray fluorescent (XRF) analyzers are essential tools for verifying that all critical metals conform to requirements independent of certifications and markings from the manufacturer. They can identify material other than that specified and help ensure product reliability and safety. These x-ray fluorescence analyzers are used for in-house QA/QC of alloy materials, coating/plating thickness verification, positive material identification of incoming alloy raw material stock, machined and fabricated parts and wear metals in oil. They give users immediate, nondestructive chemical analysis and alloy grade identification – which can help avoid hazards.

No matter what industry, material verification and positive material identification of the metal alloys used in valves has never been more important for product reliability and safety. After all, what good is a safety valve if it’s not very safe.

Additional Resources:

• Download our free eBook: A Practical Guide to Improving Steel Manufacturing Processes and Production Methods
• Visit our center for Improving Steel Manufacturing Processes and Production