Development of a Single Mechanical Seal equipped with a High-Pressure Containment Seal for Multiple Fluid Pipeline Pumps

LecturesThis paper discusses the critical design aspects, calculations, laboratory verification testing and field experience of a mechanical seal arrangement for multiple fluid Pipeline Pumps. The seal cartridge consists of a single wet lubricated mechanical seal on the product side in combination with a high-pressure containment seal on the atmospheric side. The single mechanical seal has been designed to operate in a product range from the flashing hydrocarbons ethane, propane, butane all the way up to non-flashing hydrocarbons like Natural Gasoline. Basically the single seal runs product lubricated in the media with a specific gravity range of 0,35 up to 0,65 and is designed for a pressure window up to 100bar, respecting the Pipeline Pressure. To assure this, a lift off of the mechanical seal faces at all media and at all operation conditions was targeted. To achieve this the functional components of the mechanical seal were subject of an extensive performance calculation and optimization with FEM (Finite Element Method. The mechanical seal concept includes a containment seal which withstands the full pipeline pressure in the unexpected event of a catastrophic mechanical seal failure of the single product side seal. This means massive leakage cannot leave the seal gland in an uncontrolled way under any case. To achieve similar safety and environment protection with a mechanical seal in a multiple fluid pipeline pump, conventionally a double pressurized mechanical seal with a pressurized supply system was needed. The proposed mechanical seal design provides a reliable pump sealing solution for these critical applications with a “single mechanical seal” in combination with a “high-pressure containment seal”. It provides the performance advantage and the safety philosophy of a double pressurized seal arrangement with the more costefficient single seal arrangement

Development of a Single Mechanical Seal equipped with a High-Pressure Containment Seal for Multiple Fluid Pipeline Pumps

LecturesThis paper discusses the critical design aspects, calculations, laboratory verification testing and field experience of a mechanical seal arrangement for multiple fluid Pipeline Pumps. The seal cartridge consists of a single wet lubricated mechanical seal on the product side in combination with a high-pressure containment seal on the atmospheric side. The single mechanical seal has been designed to operate in a product range from the flashing hydrocarbons ethane, propane, butane all the way up to non-flashing hydrocarbons like Natural Gasoline. Basically the single seal runs product lubricated in the media with a specific gravity range of 0,35 up to 0,65 and is designed for a pressure window up to 100bar, respecting the Pipeline Pressure. To assure this, a lift off of the mechanical seal faces at all media and at all operation conditions was targeted. To achieve this the functional components of the mechanical seal were subject of an extensive performance calculation and optimization with FEM (Finite Element Method. The mechanical seal concept includes a containment seal which withstands the full pipeline pressure in the unexpected event of a catastrophic mechanical seal failure of the single product side seal. This means massive leakage cannot leave the seal gland in an uncontrolled way under any case. To achieve similar safety and environment protection with a mechanical seal in a multiple fluid pipeline pump, conventionally a double pressurized mechanical seal with a pressurized supply system was needed. The proposed mechanical seal design provides a reliable pump sealing solution for these critical applications with a “single mechanical seal” in combination with a “high-pressure containment seal”. It provides the performance advantage and the safety philosophy of a double pressurized seal arrangement with the more costefficient single seal arrangement

High Pressure, High Temperature Shaft Seal For A Multiphase Subsea Pump

LectureThe paper describes a totally re-engineered mechanical seal for multiphase subsea pumps with a focus on extended metal and seal face material selection as well as more stable seal behavior, achieved with a new face concept, which provides enhanced reliability and robustness. It reports the design process, starting from the project description with definition of targets followed by a theoretical evaluation of the seal performance and a description of the final design features. Increasing demand for high pressure and high temperature (HP/HT) pumps in Subsea multiphase applications requires the development of mechanical seals designed for pressure levels up to 15 kpsi and product temperatures up to 350°F with the capability to handle reverse pressure conditions. With the high pressure requirements the application of spring-energized polymer gaskets as static and dynamic secondary seals using a specific design for enhanced reverse pressurization capability were selected. To achieve enhanced robustness of the seal faces in transient dry running condition which may occur during upset conditions (such as reverse pressure) the design was optimized to include microcrystalline diamond coated seal faces. A detailed analysis of face deformation and seal performance under load with a combined structure and fluid analysis software together with an extensive test campaign and specific cooling jacket features lead to a robust mechanical seal design with optimized pressure distribution and mechanical contact zones

SUMO conjugation of STAT1 protects cells from hyperresponsiveness to IFNγ

The biologic effects of IFNγ are mediated by the transcription factor STAT1. The activity of STAT1 is inhibited by small ubiquitin-like modifier (SUMO) conjugation. This occurs both directly through decreasing STAT1 tyrosine phosphorylation and indirectly by facilitating STAT1 dephosphorylation consequential to increased STAT1 solubility because of suppressed paracrystal assembly. However, the physiologic implications of SUMO conjugation have remained unclear. Here, we used fibroblasts and bone marrow–derived macrophages (BMMs) from knockin mice expressing SUMO-free STAT1 to explore the consequences of STAT1 sumoylation for IFNγ signaling. Our experiments demonstrated buffer property of paracrystals for activated STAT1, such that SUMO-mediated paracrystal dispersal profoundly reduced phosphorylation of STAT1, which affected both the activating tyrosine 701 and the transcription-enhancing serine 727. Accordingly, the curtailed STAT1 activity in the nucleus caused by SUMO conjugation resulted in diminished transcription of IFNγ-responsive genes; and increased the IFNγ concentration more than 100-fold required to trigger lipopolysaccharide-induced cytotoxicity in bone marrow–derived macrophages. These experiments identify SUMO conjugation of STAT1 as a mechanism to permanently attenuate the IFNγ sensitivity of cells, which prevents hyperresponsiveness to this cytokine and its potentially self-destructive consequences. This sets the mode of SUMO-mediated inhibition apart from the other negative STAT regulators known to date

Suicide and Personality Traits: A Multicenter Study of Austrian and Italian Psychiatric Patients and Students

OBJECTIVE: The aim of this multicenter study was to investigate the differences in personality traits, particularly Neuroticism, in three clinical samples and three student samples in Austria and Italy and their impact on suicide. METHODS: In total, 1,043 people (410 psychiatric inpatients and 633 university students) were tested in three regions of Europe: central Italy, northeast Italy, and eastern Austria. Psychiatric diagnoses were evaluated using the Mini-International Neuropsychiatric Interview, and the following instruments were used: Sociodemographic Questionnaire, Columbia-Suicide Severity Rating Scale-B, Symptom-Checklist-90-Standard, and Big Five Inventory. RESULTS: The study found that the intensity of Suicidal Ideation was associated with the personality traits of Neuroticism, Anxiety, and Extraversion but also with Depression. CONCLUSIONS: In conclusion, without the presence of Depression symptoms, neuroticism was a protective factor against Suicidal Ideation, whereas neuroticism when comorbid with Depression symptoms increased suicide risk in psychiatric patients. In all three regions, the clinical samples had higher scores for Neuroticism and for Depression symptoms than the student sample and consequently higher scores for Suicide. Furthermore, we demonstrated an interaction between gender and culture on personality traits, supporting the hypothesis that the distribution of self-reported personality traits is organized geographically.status: publishe

Suicide and Personality Traits: A Multicenter Study of Austrian and Italian Psychiatric Patients and Students

Objective: The aim of this multicenter study was to investigate the differences in personality traits, particularly Neuroticism, in three clinical samples and three student samples in Austria and Italy and their impact on suicide. Methods: In total, 1,043 people (410 psychiatric inpatients and 633 university students) were tested in three regions of Europe: central Italy, northeast Italy, and eastern Austria. Psychiatric diagnoses were evaluated using the Mini-International Neuropsychiatric Interview, and the following instruments were used: Sociodemographic Questionnaire, Columbia-Suicide Severity Rating Scale-B, Symptom-Checklist-90-Standard, and Big Five Inventory. Results: The study found that the intensity of Suicidal Ideation was associated with the personality traits of Neuroticism, Anxiety, and Extraversion but also with Depression. Conclusions: In conclusion, without the presence of Depression symptoms, neuroticism was a protective factor against Suicidal Ideation, whereas neuroticism when comorbid with Depression symptoms increased suicide risk in psychiatric patients. In all three regions, the clinical samples had higher scores for Neuroticism and for Depression symptoms than the student sample and consequently higher scores for Suicide. Furthermore, we demonstrated an interaction between gender and culture on personality traits, supporting the hypothesis that the distribution of self-reported personality traits is organized geographically

Influence of Spiritual Dimensions on Suicide Risk: The Role of Regional Differences

The field of suicide prevention has been enriched by research on the association between spirituality and suicide. Many authors have suggested focusing on the various dimensions of religiosity in order to better understand the association between religion and suicidal risk, but it is unclear whether the relationship between spirituality and suicidality differs between countries with different cultures, life values, and sociohistorical experiences. To explore this, the aim of this multicenter study was to investigate the possible relationship between suicide and spirituality in Italy and Austria. In the two countries, two different groups of subjects participated: psychiatric patients and university students. The patients were evaluated with the Mini International Neuropsychiatric Interview. In addition, the following measures were used: a sociodemographic questionnaire, the Columbia-Suicide Severity Rating Scale-B, the Symptom-Checklist-90-Standard, and the Multidimensional Inventory for Religious/Spiritual Well-Being. Our results confirmed the multifactorial nature of the relation between suicide risk and the various religious/spiritual dimensions, including religious/spiritual well-being and hope immanent. However, regional differences moderated this relationship in both the clinical and nonclinical samples.status: publishe