VALVE MAGAZINE Fall 2025

ADVANCED SEALING TECHNOLOGIES FOR SUBSEA

ensures tight sealing in high-pressure conditions; no need for gland tightening as seals react to changing pressure conditions; tight sealing up to 30,000 psi. Disadvantages : Design can be more complex and costly; requires more care in installation to avoid damaging critical sealing surfaces. • V-ring seals: These seals, with a V-shaped cross-section, are typically made from PTFE, PEEK and elastomers like NBR, HNBR, EPDM or FKM. With the use of male/ female adapters, they can easily be configured as unidi rectional or bidirectional seal assemblies depending on the orientation of the rings. Consisting of multiple sealing elements, materials and seal geometries are easily tailored to suit the specific challenges of an appli

valves and the applications where the valves will be used. Using the correct products is the best way to ensure the integ rity of the valve and protect the system, employees and the environment from product failures or malfunction due to incorrect specifications.

ABOUT THE AUTHOR

Mike Hedger is director of product management at CDI Products. He has nearly two decades of experience with high-tech polymer materials and specialized product design for sealing and bearing systems.

cation. To achieve constant tight sealing as temperatures/pressures fluctuate, the entire seal assembly is spring loaded axially by external springs often embedded in the valve body, keeping the V-rings flared out to maximize sealing stresses. V-rings are also commonly used in valve stem packing and can be added behind OEM seals to provide a more redundant and robust sealing system. Advantages: Flexible, adapting to misalignment and pressure dilation; more cost-effective and easier to install; suitable pressures up to 10,000 psi in dynamic applications. Disadvantages : Limited to lower pressures compared to spring-en ergized seals; seal wear greatly reduces applied spring loads reducing sealing stress over time and may create greater friction. Consequences of SPE and DPE seal failure in subsea valves Seal failures in subsea valves can lead to significant operational, safety, and envi ronmental consequences, with distinct impacts based on seat type and location ( see table, opposite page). Experience required to ensure long term seal success Choosing the correct seal types and configurations is paramount to ensuring performance as well as compliance with API standards. Users should work with their valve OEM or sales partner to ensure that the valves selected meet the requirements for their applications, including materials for the specific media that will be flowing through the

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FALL 2025

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