OAKTrust :: Browsing by Author "Schiavello, Bruno"

Browsing by Author "Schiavello, Bruno"

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Abnormal Vertical Pump Suction Recirculation Problems Due To Pump-System Interaction
(Texas A&M University. Turbomachinery Laboratories, 2004) Schiavello, Bruno; Smith, Donald R.; Price, Stephen M.; International Pump Users Symposium (21st : 2004)
It is well documented that the proper operation of vertical centrifugal pumps is greatly dependent upon the entire pump/piping system, which includes the piping geometry and the system operating conditions. Oftentimes, pump operate satisfactorily during shop tests but experience problems after they are installed in the field. Here, three large vertical pumps that operated satisfactorily on the test stand experienced excessive vibration after installation. Additionally, pulsation in the system piping was found to be causing unexpected vibration in downstream equipment. It was discovered that the problems were the result of complex interaction between several phenomena. Improper inlet conditions caused suction recirculation that generated broadband turbulence. The turbulent energy excited acoustical resonances of the pump/piping system, resulting in pulsation at several discrete frequencies. This energy subsequently excited mechanical natural frequencies of the motor/pump/piping system causing high amplitude nonsynchronous vibration of the pump and other structurers far downstream from the pump. Field data are presented. Diagnostic techniques and instrumentation needed to obtain the field data required to solve these problems are discussed. Also, additional data from pump hydraulic analysis and sump model tests are presented. Further, the solution strategy with two-step field changes (sump and pump) is shown. Following these modifications, the pumps have operated satisfactorily for more than four years.
Cavitation And Recirculation Field Problems
(Turbomachinery Laboratories, Department of Mechanical Engineering, Texas A&M University, 1992) Schiavello, Bruno; International Pump Users Symposium (9th : 1992)
Cavitation And Recirculation Troubleshooting Methodology
(Turbomachinery Laboratories, Department of Mechanical Engineering, Texas A&M University, 1993) Schiavello, Bruno; International Pump Users Symposium (10th : 1993)
High reliability and large rangeability are required of pumps in existing and new plants which must be capable of reliable on-off cycling operations and especially low load duties. The reliability and rangeability target is a new task for the pump designer/researcher and is made more challenging by cavitation and/or suction recirculation effects, primarily, the pump damage. Knowledge about design critical parameters and t heir optimization, and field problems diagnosis and troubleshooting has advanced considerably in recent years. The objective of the pump manufacturer is to develop design solutions, and troubleshooting approaches that improve the impeller life as related to cavitation erosion, and to enlarge the reliable operating range by minimizing the effects of the suction recirculation. A short description of several failure modes, including damage patterns and other symptoms, which are related to cavitation and/or suction recirculation is presented. The troubleshooting methodology is described in detail, focusing on the various steps of failure analysis diagnosis, and solution strategy, including quick fixes and ultimate solutions along with new material. The troubleshooting method essentially is focused on failures characterized by metal damage.
Cavitation/NPSH (Field Problems)
(Turbomachinery Laboratory, Texas A&M Engineering Experiment Station, 2018) Schiavello, Bruno; Visser, Frank; Green, Patrick; Henry, David; Atkins, Ken; Cicatello, Giancarlo; Annese, Francesco; Curtin, Greg; Adams, Ron; International Pump Users Symposium (34th : 2018)
Unexpected cavitation erosion Key parameters to consider for Root Cause Analysis when experiencing cavitation damage NPSHR, NPSHA, NPSH margin Performance loss due to insufficient NPSHA (margin) NPSH 40,000 hours Cavitation erosion rate and impeller life assessment Impact of dissolved and/or entrained gas Pumping hot water or hydrocarbons Reliability of operating with low NPSHA on hydrocarbons High cavitation-resistant materials Common types of pump cavitation, including: sheet cavitation, suction recirculation induced vortex cavitation, corner (vortex) cavitation, and tip vortex cavitation Suction specific speed Field cases (suggested by audience) : Quick fix and ultimate solution
Centrifugal Pumps: Operation, Maintenance and reliability, Vertical Pump Problems and Solutions
(Turbomachinery Laboratory, Texas A&M Engineering Experiment Station, 2018) Schiavello, Bruno; Yoo, Jihoon
Suggested Topics: • Seal plan which was not expected – wrong for the application • Preventive/predictive technologies Off design operation • Mean time between failure – how do we measure, and how do we use the metrics • How to create pump reliability in an unreliable plant • Seal-less versus sealed pump reliability, canned motor pumps versus mag drive pump reliability • Mechanical Integrity Inspections of VS 6 pumps in hydrocarbon service • Seals in light hydrocarbon service – operations, risk, leak response, maintenance • Pump predictive/preventive maintenance program elements 3. • Measures of effectiveness of preventive and predictive programs for pumps • Roles of operations and maintenance/reliability in improvements and data collection • Reliability experience with liquid versus non contacting gas seals applications • Maintenance philosophy for pumps • Spare parts – OEM versus non-OEM Repairs – OEM versus non-OEM service facilities • Pump foundation, alignment and pipe strain influence of reliability • Impact of corporate purchasing alliances on pump reliability o Repair facilities alliances o New equipment purchasing alliances • Repair techniques and material improvements • Portable and on-line monitoring – impact on reliability • Wireless monitoring – impact on reliability and risk of failure • Optimization of thrust bearings configuration • Lubrication system im
Enhancement of Pump/Plant Performance by Correct Evaluation of Process Fluid Viscosity Variations and Pump Geometry
(Turbomachinery Laboratories, Texas A&M Engineering Experiment Station, 2016) Cicatelli, Giancarlo; Schiavello, Bruno
Case Study 16: In the modern pump industry, processed fluids are characterized by a wide spectrum of viscosity values. An unpredicted variation of actual process fluid properties, including viscosity, may lead to unexpected pump performance alteration. Also manufacturing deviations from expected internal pump geometry may cause pump performance deterioration. Both causes may determine undesired limitations of the pump operating range and plant production loss. The present Case Study illustrates a real case story of incorrect evaluation of the process fluid viscosity and pump geometry deviations, both determining performance deteriorations, described through a detailed evaluation of the internal pump losses. From the presentation of a real case, this case study highlights the importance of both the correct evaluation of viscous effects and the internal pump geometry through the application of existing loss correlations.
Fast and Ultimate Vibration Field Solution: From Problem Detection to Field Performance Validation
(Turbomachinery Laboratory, Texas A&M Engineering Experiment Station, 2022) Cicatelli, Giancarlo; Schiavello, Bruno
Fast and Ultimate Vibration Field Solution: From Problem Detection to Field Performance Validation
(Turbomachinery Laboratory, Texas A&M Engineering Experiment Station, 2011) Cicatelli, Giancarlo; Schiavello, Bruno
Summary: The case. Initial analysis. Root cause analysis. Solution implementation. Results. Conclusions.
Fast And Ultimate Vibration Field Solution: From Problem Detection To Field Performance Validation
(Texas A&M University. Turbomachinery Laboratories, 2010) Cicatelli, Giancarlo; Panceri, G.; Scotti, A.; Schiavello, Bruno; International Pump Users Symposium (26th : 2010)
Improvement of Pump/Plant Performance by Sound Evaluation of Both Process Fluid Viscosity Change and Pump Internal Leakage
(Turbomachinery Laboratory, Texas A&M Engineering Experiment Station, 2022) Cicatelli, Giancarlo; Schiavello, Bruno
In the modern pump industry, processed fluids are characterized by a wide spectrum of viscosity values. An unpredicted variation of actual process fluid properties, including viscosity, may lead to unexpected pump performance alteration. Also manufacturing deviations from expected internal pump geometry may cause pump performance deterioration Both causes may determine undesired limitations of the pump operating range and plant production loss.The present Case Study illustrates a real case story of incorrect evaluation of the process fluid viscosity and pump geometry deviations, both determining performance deteriorations, described through a detailed evaluation of the internal pump losses. From the presentation of a real case, this case study highlights the importance of both the correct evaluation of viscous effects and the internal pump geometry through the application of existing loss correlations.
METS2 Short Course 2
(Turbomachinery Laboratory, Texas A&M Engineering Experiment Station, 2013) Schiavello, Bruno; Visser, Frank
Multiphase Gas-Liquid Pumping
(Texas A&M University. Turbomachinery Laboratories, 1996) Cooper, Paul; Schiavello, Bruno; Salis, Jacques de; Marolles, Charles D.; Prang, Allan J.; Broussard, Dan; International Pump Users Symposium (13th : 1996)
Pumping crude oil and gas without prior separation greatly reduces the machinery and platform space required. Multiphase pumps can be located at the surface or subsea and are designed primarily as a) two-screw rotary or b) multistage rotordynamic machines that can ingest 90 to 100 percent gas by volume. Each type has advantages and disadvantages, as can be seen from the growing body of test experience, both in the laboratory and the field. Six authors contributed the following five sections, in an effort to provide all facets of the subject in one tutorial.
P11 - Cavitation/NPSH (Field Problems)�
(Turbomachinery Laboratory, [2019]) Viser, Frank; Schiavello, Bruno; Korkowski, Frank; Henry, David; Annese, Francesco; Curtin, Gre; Atkins, Ken; Green, Patrick; Adams, Ron; Cicatelli, Giancarlo
Unexpected cavitation erosion Key parameters to consider for Root Cause Analysis when experiencing cavitation damage NPSHR, NPSHA, NPSH margin Performance loss due to insufficient NPSHA (margin) NPSH 40,000 hours Cavitation erosion rate and impeller life assessment Impact of dissolved and/or entrained gas Pumping hot water or hydrocarbons Reliability of operating with low NPSHA on hydrocarbons High cavitation-resistant materials Common types of pump cavitation, including: sheet cavitation, suction recirculation induced vortex cavitation, corner (vortex) cavitation, and tip vortex cavitation Suction specific speed Field cases (suggested by audience) : Quick fix and ultimate solution
P5 - Pump Cavitation - Physics, Prediction, Control, Troubleshooting
(Turbomachinery Laboratory, [2019]) Schiavello, Bruno; Visser, Frank
This short course gives insight into roto-dynamic pump cavitation and provides deeper understanding of particulars like cavitation inception, three-percent head drop, 40,000 hours life criterion, cavitation damage potential, NPSHR scaling laws, the effect of dissolved gas, and thermodynamic effect for hot water and hydrocarbons. Empirical correlations for predicting various types of NPSHR and the use of CFD will be discussed, and suction specific speed will be critically reviewed, along with criteria for NPSHA margin. Furthermore, the effect of fluid transients and viscosity will be addressed. Cavitation damage potential will be fully explained by the Cavitation Modes Map, which reflects fundamental insight gained since the 1940s; here in particular the striking departure in shape from the NPSH3 curve for part flows is highlighted, being a key reason of many cavitation pump problems. Attention is further devoted to Impeller Life Expectancy and Cavitation Control with modern designs tools. In conclusion, four field case studies will demonstrate the use of cavitation failure analysis and solution strategy.
Pump Cavitation - Physics, Prediction, Control, Troubleshooting
(Turbomachinery Laboratories, Texas A&M Engineering Experiment Station, 2015) Visser, Frank C.; Schiavello, Bruno; International Pump Users Symposium (31st : 2015)
Pump Cavitation - Physics, Prediction, Control, Troubleshooting
(Turbomachinery Laboratories, Texas A&M Engineering Experiment Station, 2016) Schiavello, Bruno; Visser, Frank; International Pump Users Symposium (32nd : 2016)
Pump Cavitation - Various NPSHR Criteria, NPSHA Margins, Impeller Life Expectancy (Unpublished)
(Texas A&M University. Turbomachinery Laboratories, 2007) Schiavello, Bruno; Visser, Frank C.; International Pump Users Symposium (23rd : 2007)
Pump Cavitation -- Physics, Prediction, Control, Troubleshooting
(Turbomachinery Laboratory, Texas A&M Engineering Experiment Station, 2018) Schiavello, Bruno; Visser, Frank; International Pump Users Symposium (34th : 2018)
This short course gives insight into roto-dynamic pump cavitation and provides deeper understanding of particulars like cavitation inception, three-percent head drop, 40,000 hours life criterion, cavitation damage potential, NPSHR scaling laws, the effect of dissolved gas, and thermodynamic effect for hot water and hydrocarbons. Empirical correlations for predicting various types of NPSHR and the use of CFD will be discussed, and suction specific speed will be critically reviewed, along with criteria for NPSHA margin. Furthermore, the effect of fluid transients and viscosity will be addressed. Cavitation damage potential will be fully explained by the Cavitation Modes Map, which reflects fundamental insight gained since the 1940s; here in particular the striking departure in shape from the NPSH3 curve for part flows is highlighted, being a key reason of many cavitation pump problems. Attention is further devoted to Impeller Life Expectancy and Cavitation Control with modern designs tools. In conclusion, four field case studies will demonstrate the use of cavitation failure analysis and solution strategy.
Pump Cavitation Physics, Prediction, Control, Troubleshooting
(Turbomachinery Laboratory, Texas A&M Engineering Experiment Station, 2017) Schiavello, Bruno; Visser, Frank; International Pump Users Symposium (33rd : 2017)
Pump Cavitation Physics, Prediction, Control, Troubleshooting
(Texas A&M University. Turbomachinery Laboratories, 2014) Schiavello, Bruno; Visser, Frank C.; International Pump Users Symposium (30th : 2014)
This short course deals with cavitation in general and rotodynamic pump cavitation in particular. It gives an introduction to the subject matter and provides insights in particulars like cavitation inception, 3% head drop, and 40,000 hours impeller life, as well as NPSH scaling laws. It further devotes attention to the effect of dissolved gases, and thermal suppression (i.e. thermodynamic effect) when pumping hot water or hydrocarbons. For (hydrocarbon) mixtures it will also be outlined that cavitation intensity can be expected to be far less than with pure fluids. With regard to numerical prediction capabilities the use of Computational Fluid Dynamics (CFD) shall be discussed, and empirical correlations will be presented. Furthermore, some guidance for cavitation damage diagnosis shall be given, including prediction of cavitation erosion rate, and assessment of impeller life expectancy. Also addressed are suction specific speed, and how this dimensionless group tends to cause bias and give rise to misunderstanding and misinterpretation. In this context also the corrected suction specific speed will be presented, and the concept of suction energy will be discussed. Furthermore, NPSHR criteria and establishing NPSHA margins will be outlined. As special modes of operation, the effect of fluid transients will be highlighted, demonstrating that such may yield excessive cavitation. Furthermore, a qualitative “Cavitation Modes Map” will be presented, which reflects five decades of fundamental cavitation observations and experimental facts (laboratory research and field data) published in the years 1941 – 1991. In particular, the typical shape of the erosion curve versus flow – seemingly peculiar, but fully supported by cavitation physics for all types of rotodynamic pumps – is discussed by highlighting an absolutely striking departure from the shape of conventional NPSHR3% curve (universally used for decades) at part flows. This deviation, which has been fully ignored in the past and is today still often neglected at various stages (pump specifications and selection, pump design, and field root cause analysis) is a primary reason of the majority of cavitation pump problems, as will be explained in this short course. The course further includes four Field Case Studies demonstrating the practical application of “Cavitation Failure Analysis – Methodology (Diagnosis and Solution Strategy)“, covering low and high energy, single- and multistage, pumps.

Browsing by Author "Schiavello, Bruno"

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