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valve overhauling Vs replacement

HI,

Is there a guideline which talks about valve overhauling/replacement, when to overhaul a valve Vs replace the valve. Any thoughts please. Is it a vendor recommendation or a user decision? 

Thank you 

4 Replies

  • John, my experience is on the less expensive valves, 60-65% cost of new is where most will go from an overhaul to a replacement. For the more expensive valves like Severe Service, the percentage goes higher, as much as 75-80%. Also the allowable time to turn the valve around during an overhaul comes in to play, for the smaller valves it might be cost effective to go with new and swap out turning field jobs (un-install and then Install) from two separate events to one event. Sometimes set up time for crane, etc. can make this very attractive.

    Craig Jeane | Business Mgr., Severe Svc
    Puffer-Sweiven | 903 Highway 146 South | La Porte | Texas | 77571 | US
    A Member of the Emerson Impact Partner Network

  • In reply to Craig Jeane:

    Seconding what Craig Jeane said, your cost estimation needs to look at downtime as well. At a minimum, critical components need a spare, so that if a valve is failing, you can it out with your good spare and then continue operation. If you don't have a spare, now is a good time to justify the purchase of a new unit. Then, once the swap is complete, you have the luxury of time to determine whether you are going to overhaul the failed valve or back fill your spare with another new one. Craig's percentages seem pretty reasonable to me, but it also depends on your operating margins and component cost. Above a certain cost, it gets very hard to justify buying a new valve, if it is simply unaffordable, while overhaul may be just within your budget. Conversely, for minor "consumable" parts, it may be cheaper to buy an overhaul kit, but the labor cost of the repair may make a new valve more cost-effective, net.

    Lastly, and here is the tricky / ugly bit: Is the valve in need of an overhaul needing that overhaul in a reasonable amount of time, given service and projected lifespan from the OEM? In other words: Is it the right valve for the job, or, before you buy a spare, should you revisit the specification? Generally valves and other big-ticket items are sufficiently long-lived that the process industry has likely come up with a generational improvement by the time you need a new one. And, if the valve's life is short, compared to what was expected, maybe you need to change materials, etc. to last longer in that service. Even if each overhaul is relatively cheap, there's no point in overhauling a valve time and again, when it could be replaced with the right one for the job.
  • Craig provided a very good guideline and practical response. I might add a recommendation to call the local sales office to discuss the particular situation at hand, as this isn’t a “one size fits all” approach. There are a lot of things to consider when deciding to overhaul or replace a valve, like criticality of the application, management of change requirements of the facility, return on investment of both options, etc. The sales office should be able to help work through the details to help decide the best option.
  • In reply to Jaime.Miller:

    If I may add, Valve Diagnostics will be useful in determining the condition of the valve prior to deciding whether to overhaul or replace the valve.

    If the control valve positioner on the valve that you are planning to overhaul/replace is capable of providing data related to the health of the valve assembly, you can first run diagnostics to check if there is a need to carry out maintenance work.

    There are lots of data available in a valve positioner that provide insights to the valve assembly, example like number of cycles and run time the valve has been through, to determine the needs of changing the soft parts.

    From the diagnostics, you can decide the next steps forward depending on:
    - Spare parts availability
    - Spare parts delivery
    - Schedule for resources and equipment
    - Maintenance window