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Recent content by RefineryRR

  1. RefineryRR

    Fluid vaporising, but not cavitating...

    Has anyone experienced a phenomenon where their pumped fluid vaporises and condenses again, but does not actually cavitate. If so, what failures do you experience? What findings do you make on your pump internals (particularly your seals)? Etc.
  2. RefineryRR

    Sundyne LMV-322 Barrier Fluid Leak (MTBF ~20 hours)

    JJPellin, I am encouraged by your previous post as that is my theory of what is going on. My suspicion is that we have significant quantities of products with density extremes, causing the thrust on the high-speed shaft to vary. If this is the failure mode: what damage would you expect to see...
  3. RefineryRR

    Sundyne LMV-322 Barrier Fluid Leak (MTBF ~20 hours)

    We've measured the suction pressure and it is as per design - 10 bar. There are no strainers at the suctions of these points. Any significant obstruction would create an NPSH problem, which we do not see evidence of on the impeller, inducer or diffuser throat. The inducer is unchanged. There is...
  4. RefineryRR

    Sundyne LMV-322 Barrier Fluid Leak (MTBF ~20 hours)

    My apologies we do have an external flush (plan 32) on this pump in addition to the plan 53B. We will do those specification checks as you recommended. With regards to the gearbox issues you raised, I doubt these will be the cause as the gearbox used in this service is used in multiple other...
  5. RefineryRR

    Sundyne LMV-322 Barrier Fluid Leak (MTBF ~20 hours)

    Impeller Speed: 8,400 RPM There is no plan 11 or 31 on this pump; only 53B The barrier fluid pressure is 15 - 20 bar (measured operating stuffing box pressure is approximately 11 - 12 bar) The motor direction is correct The barrier fluid type has not changed. This barrier fluid is used...
  6. RefineryRR

    Sundyne LMV-322 Barrier Fluid Leak (MTBF ~20 hours)

    Good day All We have a Sundyne LMV-322 pump with a Plan 53B seal system, operating in HF Alkylation service (product is a combination of propane, butane & HF acid). This set of pumps are our refinery's number 1 & 2 bad actors. We experience a high-frequency of failures on these pumps will...
  7. RefineryRR

    Recip Compressor: Piston & Rider Ring Wear

    Due to various reasons, our rod-drop measuring capabilities are not available. What would be the best way of tracking piston & rider ring wear for a study? Some have suggested using a feeler gauge to measure the top clearances but this only gives you the sizes of the outermost (crack-end) rings...
  8. RefineryRR

    Angular Contact: Face-to-Face vs. Back-to-Back

    What is the impact (or consequence) of installing a pair of angular contact bearings (e.g. 7310BG) in a Face-to-Face orientation, vs. a Back-to-Back orientation? Similarly, what are the benefits & disadvantages of each configuration?
  9. RefineryRR

    Journal/Sleeve Bearing Clearance

    How do equipment manufacturers determine the journal bearing clearances for their pumps, compressors, etc.? Is there a rule-of-thumb for determining the optimal bearing clearances (metric)? Do manufacturers use 'hyper-theoretical' means of determining these clearances? By this, I mean, do they...
  10. RefineryRR

    Low Flow, High Pressure Water Injection (Refinery)

    shvet2008 What failures do you experience? Have you identified the root causes of your failures? What is the average MTBF for these pumps? Do you use any other types of wash water or water injection pumps?
  11. RefineryRR

    Low Flow, High Pressure Water Injection (Refinery)

    With such high differential pressures across a single impeller, is the machine not invariably exposed to discharge-to-suction internal recirculation and resulting cavitation? One would be inclined to say that if the API-specified min wear ring clearances are maintained this shouldn't be a...
  12. RefineryRR

    Low Flow, High Pressure Water Injection (Refinery)

    JJPellin, I am looking for more detail on what systems are being used at refineries worldwide; "centrifugal" pumps is not sufficiently detailed. As I said in my intro, I am looking for pump manufacturers & models. I am also looking for details regarding the achieved MTBF, lessons learnt...
  13. RefineryRR

    Low Flow, High Pressure Water Injection (Refinery)

    For those operating low flow, high pressure water injection pumps in crude oil refineries, can you please share with us: 1. What type of pump you are using (i.e. type, manufacturer, model) 2. Differential Head, Suction Head and Flow Rate 3. Average MTBF achieved I am operating a reduced crude...
  14. RefineryRR

    Priming a Pump in Suction Lift Service

    An excellent suggestion, LittleInch. A foot valve at the suction line entry may be the simplest, and most cost-effective approach. There is minimal DP across the theoretical check valve; the only consideration will need to be the head loss across is, as the NPSHA is already very close to the...
  15. RefineryRR

    Priming a Pump in Suction Lift Service

    Problem Statement: The pump (shown in the crude sketch attached) is a basic overhung, centrifugal pump which is required to pump out salt water from a pond (at approximately 20 m3/h). Due to the suction line extending over the bund wall to enter the pond, there is an accumulation of air in the...
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