- Published on Tuesday, 15 April 2008 20:56
- Written by Patrick Leask
In today’s competitive business environment, myriad challenges face the owner/operator of an industrial process plant. With economic pressures to get more out of invested assets, a steady progression toward truly global supply chains and end-user markets, and more stringent regulatory constraints, the industrial world is increasingly complex. To prosper in this environment, owner operators are relying more on equipment suppliers and business partners to ensure compliance to regulatory standards and to leverage the latest developments in technology. Add to this mix elevated criticality of safety in the process arena, and it is clear industry must make the most of every opportunity to effectively manage complexity and mitigate risks.
Between Risk and Reward
In managing a business in this environment the proper balance between risk and reward must be established and maintained. For a process plant the most potent risks are those that threaten safety or reduced process uptime or availability. Despite the high associated risk, not all process plant owner operators rely solely on OEM parts for engineered equipment or OEM or OEM-certified third parties for servicing that equipment. Use of non-OEM parts and non-certified service suppliers are arguably the one common sourcing practice that poses the highest safety and/or downtime risk in a modern process plant. Further, it can be argued that OEM sanctioned supply of parts and service is particularly prudent for support of industrial valve assets.
Of all the equipment in a process plant, valves are perhaps the most omnipresent and critical components and are subjected to the full brunt of the process flow stream. For example, as the final control element, a control valve must reliably throttle while being subjected to the forces of fluid flow, temperature and pressure. Inaccuracies or sluggishness of control caused by poor quality final control elements cannot be overcome with the best DCS installation, advanced loop tuning or state-of-the-art measurement devices and schemes. Other industrial valves, such as emergency shutdown or safety relief valves, play a critical role in maintaining safe plant operations. From tight shutoff isolation and overpressure protection to emergency shutdown, a wide range of critical functions are performed by industrial valves.
Safeguarding Your Investment
The significant investment in valves within any industrial process plant must be safeguarded with efforts to sustain high quality and reliable performance. Exacting factory design, manufacturing, testing and certification of industrial valves must not be compromised later through ill-advised maintenance practice. In many cases the compromise to product integrity that results through sourcing of non-certified valve servicing introduces significant risks of performance degradation in control or safety function. In some instances, defects from improper servicing can lead to process downtime or even catastrophic consequences in the event of valve failure.
The impact of poor performance or failure of industrial valves is clear, but why does uncertified or worse, unqualified, service pose such a high risk to proper valve function? Unqualified technicians using improper service methods can affect the quality of individual valve component parts, and improper assembly technique clearly can affect overall valve performance integrity. When using sources not sanctioned by the OEM for valve service, the process owner cannot be assured that industry standards and equipment certifications are maintained. Indeed, ANSI, ASME, PED, OSHA, FM and other industry and product qualifications and certifications can be compromised through improper service or maintenance practice. Furthermore, non-sanctioned sources using improper servicing practice can compromise basic function, performance or safety integrity of the valve as originally designed and manufactured. Simply put, poor service technique yields poor valve quality. And of course, poor valve quality impacts process reliability and safety.
In addition to increased incidence of problems (Table 1), the use of non-sanctioned service providers gives the plant owner/operator less recourse in product liability cases. OEM manufacturers typically do not honor warranty obligations if non-qualified, third-party servicing causes any deterioration of product integrity. Similarly, legal recourse is limited as the owner/operator has contributed to the problem by adding risk through the use of non-qualified suppliers.
To ensure problems don’t occur, only the OEM can draw upon knowledge of product design details and ready access to the most relevant experience in product specific application skill. To ensure design integrity is maintained throughout the product lifecycle, servicing is ideally performed by the OEM or OEM-certified service organizations that deploy technicians who are trained extensively prior to certification. After receiving both classroom and hands-on experience, technicians typically are tested through written and practical application. Each certified service organization must also maintain proper certificates of authorization, such as those from ASME, in addition to maintaining OEM certification enforced through regular audit.
A Range of Services
Furthermore, most OEMs offer a broad range of services not available from the non-OEM, constituting a whole set of capability that can be described as “service to improve” rather than “repair to restore.” While the non-OEM source can typically only recondition or repair a valve to “as was” condition, the OEM has full technical backing to help end- users improve valve performance and reliability through advanced services such as diagnostics, design and application engineering support, and migration to improved technology. Even for non-critical valves being reconditioned, OEM-certified technicians, through their valve expertise, are better equipped to deploy preventive maintenance practice that translates into significant reduction of unplanned maintenance. That capability coupled with higher quality of repair from the OEM can yield significant savings in product life-cycle costs.
To reduce the risk of valve performance problems, valve failures or process downtime, a process plant owner operator is best served by using OEM or OEM-certified repair throughout the valve’s lifecycle. OEM service and repair ensures the proper technical expertise and maintenance practice leads to reliable product performance and increased process availability. Given the importance of industrial valve assets, their contribution to safe and profitable plant operation and the risks introduced by non-sanctioned repair, OEM certified and warranted servicing is the only way to go. VM
What Can Go Wrong?
Component Dimensional Integrity
Improper fit of guiding surfaces
Excessive friction; high wear and poor control
Improper shaft/stem finish
Excessive packing wear; Leaks to environment
Improper flange gasket finish
Leaks to environment
Inaccurate seat geometry
Seat leakage; shorter trim life
Materials of Construction
Improper selection –corrosive
Shorter trim life; unexpected part failure
Improper heat treat or surface treatment
Shorter trim life; possible part failure
Improper use of lubricants / sealants
Seizing of moving parts; accelerated corrosion
Improper welding procedure
Assembly / Calibration Integrity
Improper torquing of bolted joints
Compromise of pressure containment
Improper positioner calibration
Loss of control performance
Improper seat alignment / seal assembly
Poor actuator alignment
Excessive wear; shorter life
Processing and Certification
Lack of non-destructive examination
Failure of pressure containing part
Lack of positive material identification
Failure of trim component
Lack of code qualification
Compromise of safety related integrity
Improper test & inspection
Increased level of defects at start-up
How to Find an OEM-Certified Facility
You’re responsible for maintaining valves, actuators and controls in an industrial application, and you recognize the importance of using OEM or OEM-certified service facilities. But how do you go about locating OEM or OEM-certified valve repair and service facilities? It’s simple. Turn to the members of the Valve Repair Council (see list of members on page 51).
The VRC was formed 20 years ago when the member companies of the Valve Manufacturers Association of America saw a need to promote both safety and quality in valve and actuator repair. As a result, the service operations of VMA members banded together to create the Valve Repair Council. Membership in the council is open to all VMA members who have either in-house service operations or out-of-plant service facilities, as well as their authorized independent facilities.