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$498.00. API 614 covers the minimum requirements for General Purpose and Special Purpose Oil Systems. The standard also includes requirements for Self-acting Gas Seal Support Systems. The standard includes the systems' components, along with the required controls and instrumentation. Data sheets and typical schematics of both system components and complete systems are also provided. Chapters included in API 614 include:.
General Requirements. Special-purpose Oil Systems. General-purpose Oil Systems. Self-acting Gas Seal Support Systems. This edition of API RP 614 is the modified national adoption of ISO, Petroleum, petrochemical and natural gas industries-Lubrication, shaft-sealing and oil-control systems and auxiliaries.
Product Details Edition: 5th Published: Number of Pages: 202 File Size: 1 file, 2.5 MB Redline File Size: 2 files, 7.6 MB Product Code(s): CX61402, CX61402, CX61402 Note: This product is unavailable in Cuba, Iran, North Korea, Syria Document History. Amendments & Errata. Browse related products from American Petroleum Institute.
The current proposal for the DSM-5 definition of social anxiety disorder (SAD) is to replace the DSM-IV generalized subtype specifier with one that specifies fears in performance situations only. Relevant evaluations to support this change in youth samples are sparse.The present study examined rates and correlates of the DSM-IV and proposed DSM-5 specifiers in a sample of treatment-seeking children and adolescents with SAD (N = 204).When applying DSM-IV subtypes, 64.2% of the sample was classified as having a generalized subtype of SAD, with the remaining 35.2% classifying as having a nongeneralized subtype SAD. Youth with generalized SAD, relative to those with nongeneralized SAD, were older, had more clinically severe SAD, showed greater depressive symptoms, and were more likely to have a comorbid depressive disorder. No children in the current sample endorsed discrete fear in performance situations only in the absence of fear in other social situations.The present findings call into question the meaningfulness of the proposed changes in treatment-seeking youth with SAD.
Results When applying DSM-IV subtypes, 64.2% of the sample was classified as having a generalized subtype of SAD, with the remaining 35.2% classifying as having a nongeneralized subtype SAD. Youth with generalized SAD, relative to those with nongeneralized SAD, were older, had more clinically severe SAD, showed greater depressive symptoms, and were more likely to have a comorbid depressive disorder. No children in the current sample endorsed discrete fear in performance situations only in the absence of fear in other social situations.
Social anxiety disorder (SAD) is one of the most common mental disorders affecting the general populationwith almost one in 10 individuals suffering from SAD at some point in their lifetime before even reaching young adulthood. Onset typically occurs in childhood or early adolescenceduring which time SAD diagnosis is associated with loneliness, dysphoria, poor social effectiveness, nicotine use, and increased peer victimization.
– Left to its natural course, SAD is associated with chronicity, multiple functional impairments, increasing comorbidity, and reduced health-related quality of life. SAD criteria have shifted across the past few decades as research on SAD phenomenology has progressed. The disorder was initially classified in DSM-III as a type of phobic reaction to a specific social situation akin to a specific phobia. With the advent of DSM-III-R and DSM-IV, diagnostic criteria for the disorder underwent significant changes. As it became clear that many individuals meeting criteria for social phobia experienced anxiety related to several varied social situations, the specifier “generalized” was introduced to the formal nosology to describe persons experiencing social fears in “most or all” situations. The label “social anxiety disorder” was introduced in DSM-IV to connote a more pervasive and interfering condition than implied by the label “social phobia” and the limited DSM-III diagnostic definition. Individuals endorsing only a circumscribed or limited number of social fears began to be classified as showing a “non-generalized” presentation of the disorder.
Generalized and nongeneralized SAD subtypes have been distinguished in several studies of adults using varied methodologies, – and in clinical studies of youth. Broadly speaking, generalized SAD has consistently been linked with clinical severity of diagnosis, and the generalized subtype assignment has come to characterize individuals with more severe disorder presentations.
Despite documented distinctions in severity between generalized and nongeneralized SAD, the validity and clinical utility of the generalized and nongeneralized specifiers have been the subject of criticism. The DSM advises to assign a “generalized subtype” if a person fears “most or all” social situations. Given imprecision in the wording of the DSM, subtype definitions have been inconsistently applied across studies, making it difficult to meaningfully compare findings. Given dissatisfaction with the limitations of the “generalized” specifier, it has been suggested that basing subtypes on thematic fear content rather than on quantity of fears may provide a more meaningful distinction with which to base future research and treatment development. As publication of the DSM-5 approaches, one key area for proposed SAD definition change concerns the removal of the “generalized” SAD specifier, and in its place including a “performance only” SAD specifier.
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This proposed specifier based on the thematic content of social fears would be utilized to identify those individuals whose “fear is restricted to speaking or performing in public.” Empirical work with adults has demonstrated that compared with other content areas, performance or public speaking fears most often occur in the absence of other social fears. Some research has supported the distinction between performance or public speaking fears from more widespread social fears among adults on a variety of measures, ranging from clinician-rated severity and temperamental vulnerability factors to psychophysiological reactivity during stressful tasks. Although empirical work has shown some support for the proposed specifier change in adult samples, relevant evaluations in youth are sparse and have not necessarily supported the proposed inclusion of a performance-only specifier for DSM-5 SAD. Recent epidemiological work in the U.S. Population using data from the National Co-morbidity Survey-Adolescent Supplement found only 0.8% of adolescents meeting criteria for SAD could be classified as having the performance-only SADcalling into question the relevance of the specifier with regard to youth. In contrast, 55.8% and 44.2% of SAD adolescents were classified as having generalized and nongeneralized presentations, respectively.
Epidemiological work with youth and young adults in Europe, by contrast, has shown some support for the utility of a performance-only SAD subtype. Specifically, Knappe and colleagues examined German youth and young adults ages 14–24 in the Early Developmental Stages of Psychopathology study and found roughly one third of those with SAD showed exclusively performance-based presentations. These performance-oriented SAD cases showed lower behavioral inhibition and clinical severity, although the inclusion of individuals up to the age of 24 limits the extent to which these findings can be interpreted as applying specifically to youth populations. Regardless, although findings from the National Co-morbidity Survey-Adolescent Supplement and the Early Developmental Stages of Psychopathology can inform our understanding of SAD presentation in the general population, such epidemiologic work does not speak to treatment-seeking youth.
Much remains to be learned about the nature and prevalence of isolated performance fears in the population of youth-seeking treatment for SAD. The present study evaluated patterns and correlates of the DSM-IV and proposed DSM-5 SAD specifiers in an outpatient treatment-seeking sample of children and adolescents. Specifically, to examine the clinical relevance of each subtype, we examined the percentage and clinical correlates of SAD youth showing generalized, nongeneralized, and performance-only presentations. PARTICIPANTS Participants included 204 consecutive treatment-seeking youth meeting diagnostic criteria for DSM-IV SAD and their parents, presenting for services at a university-affiliated center for the treatment of anxiety and related disorders in Boston, USA (2004–2012).
Children (57.4% female) ranged in age from 6 to 19 years ( M age = 13.0, SD age = 3.4); 77.9% self-identified as non-Hispanic Caucasian. Families ranged in resources: 19.6% were at or below 300% of the national poverty line for their year (e.g., in 2007 $63,609 for a family of 4; $75,240 for a family of 5) whereas 11.3% of households earned at least 600% of the national poverty line at their year of assessment (e.g., in 2007 $127,218 for a family of 4; $150,480 for a family of 5). Parents of the majority of children were married or cohabitating (80.4%); 16.7% of children’s parents were previously but no longer married, and 2.9% were never married. Regarding psychotropic medications, 23.5% of youth were taking antidepressant medication, 6.9% were taking stimulant or other ADHD medication, 6.4% were taking an antipsychotic medication, 5.4% were on taking a sedative or hypnotic medication, and 3.4% were taking a mood stabilizer.
SAD youth met additional diagnostic criteria for comorbid DSM-IV generalized anxiety disorder (42.2%), separation anxiety disorder (15.7%), specific phobia (13.2%), major depressive disorder (11.3%), obsessive–compulsive disorder (9.3%), attention-deficit hyperactivity disorder (8.8%), panic disorder with or without agoraphobia (7.8%), dysthymic disorder (5.4%), depressive disorder NOS (4.4%), selective mutism (2.9%), oppositional defiant disorder (2.9%), or posttraumatic stress disorder (0.5%). The mean number of mental disorders among SAD youth was 2.3 ( SD = 1.2). Anxiety Disorders Interview Schedule for Children and Parents for DSM-IV (ADIS-C/P) The ADIS-C/P is a semistructured diagnostic interview that assesses child psychopathology in accordance with DSM-IV criteria, with particularly thorough coverage of the internalizing disorders. The ADIS-C (child version) and the ADIS-P (parent version) collect data on children’s and parents’ reports of child anxiety, respectively. Child and parent diagnostic profiles are integrated into a composite diagnostic profile using the “or rule” at the diagnostic level, in which a diagnosis is included in the composite profile if either the parent(s) or child endorsed sufficient diagnostic criteria for that disorder.
Diagnoses are assigned a clinical severity rating (CSR) ranging from 0 (no symptoms) to 8 (extremely severe symptoms), with CSRs of 4 or above used to characterize disorders that meet full diagnostic criteria and CSRs of 3 and below used to characterize subthreshold presentations. The ADIS-IV-C/P was also used to classify SAD youth into DSM-IV and proposed DSM-5 subtypes (see SAD Youth Subclassification, below). The ADIS-C/P has been the most widely used diagnostic interview in clinical research evaluating child anxiety, likely due to its strong reliability, validity, and sensitivity to change, and in research evaluating SAD specifically.
In age ranges comparable to those of the present sample, the interview has demonstrated good reliability for parent ( κ range from 0.65 to 0.88) and child diagnostic profiles ( κ range from 0.63 to 0.88). Diagnostic reliability was strong in the present sample ( κ for all anxiety disorders ≥ 0.70).
Children’s Depression Inventory (CDI) The CDI is a widely used self-rating scale of depressive symptomatology in children. For each item, the child is asked to endorse one of three statements that best describes how he or she has typically felt over the past 2 weeks (e.g., “I am sad once in a while,” “I am sad many times,” or “I am sad all the time”). Each response is scored as either 0 (asymptomatic), 1 (somewhat symptomatic), or 2 (clinically symptomatic), contributing to an overall CDI score that can range from 0 to 54. The scale has demonstrated excellent internal consistency in both clinical and nonclinical samples ( α 0.80), – and acceptable test–retest reliability identified in both clinical and nonclinical samples.
, – Internal consistency was high in the present sample ( α 0.89). Research supports the use of the CDI as a continuous measure of depressive symptomatology in anxious youth.
PROCEDURE Participants were recruited from a university-affiliated outpatient center for the treatment of emotional disorders in Boston, USA. Families completed an initial telephone screening as part of clinic procedures. Children were excluded with current psychotic symptoms, suicidal or homicidal risk requiring crisis intervention, two or more hospitalizations for severe psychopathology (e.g., psychosis) within the previous 5 years, or moderate to severe intellectual impairments. Children on psychotropic medications were required to be stabilized at least 1 month on current dose prior to participation. Participating families were administered the ADIS-C/P and children completed the CDI as part of a prescreening battery for treatment. After obtaining informed consent, a diagnostician conducted separate child and parent interviews, and then integrated diagnostic profiles using the “or rule” to generate a composite diagnostic profile.
For each case, interview material was presented and reviewed at a weekly diagnostician staff meeting, during which time symptoms were reviewed and a team consensus on the diagnostic profile was obtained. Consistent with ADIS-C/P guidelines, diagnoses were generated in strict accordance with DSM-IV.
Diagnosticians included a panel of 22 clinical psychologists, postdoctoral associates, and doctoral candidates specializing in the assessment and treatment of pediatric anxiety disorders. All diagnosticians met internal certification and reliability procedures, developed in collaboration with one of the ADIS-C/P authors: observing three complete interviews, collaboratively administering three interviews with a trained diagnostician, and conducting supervised interviews until achieving the reliability criterion (i.e., full diagnostic profile agreement on three of five consecutive supervised assessments).
Demographic information was obtained from parent report. As in previous researchhousehold income was used to compute a poverty index ratio (i.e., household income divided by U.S. Poverty threshold in the interview year), resulting in four index ratio categories. SAD Youth Subclassification Among SAD youth, children were further classified into subtypes: (1) those exhibiting DSM-IV generalized SAD; (2) those exhibiting DSM-IV nongeneralized SAD; and (3) those exhibiting DSM-5 performance-only SAD. Generalized SAD was assigned by diagnosticians in accordance with DSM-IV—after consultation with the full diagnostic panel in a weekly staff meeting—to reflect cases in which the fears included most situations (e.g., initiating or maintaining conversations, participating in small groups, dating, speaking to authority figures, attending parties). Cases that were not assigned a generalized subtype were assigned a non-generalized subtype of SAD.
Agreement in the classification of generalized versus nongeneralized SAD was very high among diagnosticians ( κ = 0.82). To identify individuals meeting criteria for the performance subtype of SAD, a panel of doctoral-level experts from two leading pediatric anxiety disorders clinics ( N = 7) examined each of the ADIS-C/P SAD items.
Panelists were provided with the DSM-5 Development working definition for SAD performance-only subtype (i.e., “the fear is restricted to speaking or performing in public”) and independently rated whether they believed each of the 22 social situations assessed in the ADIS-C/P SAD module should be included as a “speaking/performance” symptom (see ). Social situations on which at least five of the seven panelists agreed characterized speaking or performing in public were carried forward to define youth with a performance subtype of SAD. This subtype was defined as SAD cases in which (1) at least one of these speaking/performance symptoms was endorsed with a fear rating of 4 or above (on the ADIS-C/P 0–8 fear scale), and (2) none of the remaining SAD symptoms assessed in the ADIS-C/P were endorsed with a fear rating of 4 or above. EVALUATING THE DSM-IV GENERALIZED VERSUS NONGENERALIZED SAD SUBTYPING Almost twice as many SAD youth were classified as showing generalized ( N = 131, 64.2%) versus nongeneralized ( N = 73, 35.8%) subtype. Generalized and non-generalized SAD youth did not differ with regard to gender, race/ethnicity, psychotropic medication status, or number of clinical diagnoses (see ). Generalized SAD youth were significantly older than nongeneralized SAD youth, showed greater SAD clinical severity, and exhibited higher levels of depressive symptomatology.
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Linear regression using SAD subtype to predict these clinical variables found the association between SAD subtype and SAD clinical severity persisted after controlling for child age B = 0.62, SE( B) = 0.12, β = 0.31, t = 5.12, P. EVALUATING THE PERFORMANCE-ONLY SPECIFIER PROPOSED FOR DSM-5 Evaluation of panelists’ ratings yielded seven speaking/performance items with which to define the performance subtype of SAD (see ). Almost every SAD case endorsed symptoms from this list ( N = 191, 93.6%). However, all of these cases also endorsed symptoms from the remaining list of 15 SAD symptoms that did not comprise the speaking/performance symptom set.
Accordingly, no SAD cases in the present sample (0%) were classified as meeting the criteria for the performance subtype of SAD. CONCLUSION Although it has been argued that adoption of a performance-only specifier in DSM-5 is empirically supported by work with adults, the current clinic-based investigation is consistent with general population research in failing to support the proposed SAD specifier change for children and adolescents.
Potential explanations for these findings include a potential later age of onset of the performance subtype and the developmental relevance of performance-based fears, differences in treatment-seeking behaviors across subtypes, and imprecision in the definition of the new subtype. Future research is needed to elucidate the contributions of each of these factors. Prudence would suggest SAD definition changes should be restricted to only the very minimum number of revisions necessary to offer clear improvements over existing criteria sets. The present analysis suggests that with regard to treatment-seeking children and adolescents, the proposed SAD specifier change does not offer a clear improvement.
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Printed Edition + PDF. Immediate download. $281.00. Includes December 2006 errata. API Std 613 covers the minimum requirements for special-purpose, enclosed, precision single- and double-helical one- and two-stage speed increasers and reducers of parallel-shaft design for petroleum, chemical and gas industry services. This standard is primarily intended for gear units that are in continuous service without installed spare equipment. This standard includes related lubricating systems, controls, instrumentation, and other auxiliary equipment.
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API Std 613 is not intended to apply to gear units in general-purpose service, which are covered by API Std 677; to gears integral with other equipment, such as integrally geared compressors covered by Std 617 or Std 672; or to gears other than helical. Product Details Edition: 5th Published: ANSI: ANSI Approved Number of Pages: 94 File Size: 2 files, 1.1 MB Product Code(s): C61305, C61305, C61305 Note: This product is unavailable in Cuba, Iran, North Korea, Syria Document History.
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The size and therefore the price of a gearbox depend on the gear-rating method specified. This comparison of eight commonly used standards published by the American Petroleum Institute (API), American Gear Manufacturers Association (AGMA) and the International Organization for Standardization (ISO) highlights the differences between them. Let us begin with a brief description of these standards: API 613 5th edition (2003): Special Purpose Gear Units for Petroleum, Chemical and Gas Industry Services. Since its initial publication in 1968, most of the main gearboxes in refineries have had to conform to this specification. If you specify this standard, you will probably pay substantially more for the gearbox than if another standard is used. API 613 covers not only gear rating, but also related lubricating systems, controls, and instrumentation. The conservative rating stems mainly from basing the material allowable stresses on the lowest grade materials (grade 1) from the American Gear Manufacturers Assn.
(AGMA) standard that was in effect in 1977, even though use of the better “grade 2” materials is now required. Although AGMA material-allowable stresses have increased over the years to reflect increasingly stricter metallurgical requirements, improved metallurgy and extensive field experience, the API ratings have remained unchanged. The sixth edition of API 613 is currently in development, and should be published sometime this year. It will not change the basic rating method or material allowables.
However, it does incorporate language to allow the use of alternate rating methods if the API method would result in excessive pitch line velocity or excessive face width. API 617 8th Edition API 617 8th Edition (2014): Axial and Centrifugal Compressors and Expandercompressors; Part 3 — Integrally Geared Centrifugal Compressors. This was first published in 1958 and covered only barreltype centrifugal compressors. The 2002 Seventh Edition expanded the scope to also cover Integrally Geared Centrifugal Compressors and Expander-compressors.
Each section has its own set of annexes, and Part 3 annex G, has a rating method based directly on ANSI/AGMA 2001, which specifies how each factor is to be calculated, and then imposes an additional 20% derating factor. It is fairly conservative, but not nearly as much as API 613. ANSI/AGMA 2001-D04 (2004): Fundamental Rating Factors and Calculation Methods for Involute Spur and Helical Gear Teeth. AGMA 2001 and 2101 (the metric version) are the basic AGMA gear-rating standards that most other AGMA rating standards are based on. They have evolved from standards originally published in 1946.
The user is given some flexibility in selecting the values of the factors to be used, so even given complete information on a gear set, two engineers may come up with different ratings. Therefore, specific application standards, such as API 617 part 3, AGMA 6011, or AGMA 6013, provide guidance on selecting the factors to be used in the rating. ANSI/AGMA 6013-B16 (2016): Standard for Industrial Enclosed Gear Drives. This standard generally does not apply to high-speed turbomachinery, but is included for comparative purposes. It presents general guidelines for design, rating and lubrication of parallel, concentric and rightangle shaft drives, but here we will only consider rating of parallel-shaft gearboxes.
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This standard only applies when the pitch line velocity does not exceed 35 m/s (7,000 ft/min). It specifies that ANSI/AGMA 2001- D04 is to be used for the rating, but provides the specific factors to be used. The rating is for 10,000 operating hours using the least conservative life factors. High-speed gear sets ANSI/AGMA 6011-J14 (2014): Specification for High Speed Helical Gear Units.
The first high-speed gear unit standard was adopted in 1943 and has evolved over time. It is now based on ANSI/AGMA 2001-D04, and applies when the pitch-line velocity exceeds 35 m/s. The designer has some limited choices when rating a long life gear set. The rating is for a minimum of 40,000 operating hours, using the most conservative stress cycle (life) factor. If the number of stress cycles exceeds the stress cycle factor graph endpoint, the user has the option of using the graph end point or extrapolating the curve to lower values. ISO 6336-2006 except part 5 is 2003: Calculation of Load Capacity of Spur and Helical Gears. This standard, which is composed of five separate parts, is largely based on prior DIN (German Standards Institute) standards, and is generally accepted everywhere outside of the U.S.
The AGMA Helical Gear Rating Committee has been working for many years to revise AGMA 2101 to align it with ISO 6336, but because of large philosophical differences between these standards, unification is still years away. Yet despite the differences between the AGMA and ISO rating methods, the gear ratings are often similar. The ISO working group is currently revising Parts 1 – 3, and a new edition might be published in about a year. API 672 4th edition (2004): Packaged, Integrally Geared Centrifugal Air Compressors for Petroleum, Chemical, and Gas Industry Services. Originally published in 1979, this standard directs the user to rate the gears according to ANSI/AGMA 6011. API 677 3rd Edition (2006): General- Purpose Gear Units for Petroleum, Chemical and Gas Industry Services.
This was first published in 1989, and used a modified K factor rating method. The 1997 second edition changed the rating method to that given in API 613. Table 1 Specific gear sets The gear sets used in this comparison are presented in Table 1, with changes between sets highlighted. All are alloy steel. Speeds range from 700 to 45,000 RPM. The resulting ratings range from 200 to over 18,000 HP.
An even wider range of gears could have been analyzed, but that probably would not significantly change the general conclusions of this study. Note that the values and factors chosen are sufficient for the purposes of this study, but they were selected for simplicity; they do not represent actual gears in production and should not be used as a recommendation or guide for gear design. Ratings are for 20 years of continuous operation, except ANSI/AGMA 6011-J14 specifies that ratings are for a minimum of 40,000 hours. Therefore, for comparison, ANSI/AGMA 6011 ratings are presented both for 40,000 hours and 175,200 hours (20 years). The ANSI/AGMA 6013 ratings are for 10,000 hours as stipulated. The rating results are presented even if the pinion speed or the pitch line velocity is too high or low for the standard to apply. Figure 1 shows the pitting (surface durability) power rating and Figure 2 shows the bending strength ratings, with each line representing one gear set.
Figure 3 shows the overall rating, which is simply the lower of the pitting and bending rating. For case- and surface-hardened gears, there is about a two-to-one ratio from the highest to lowest ratings for a specific gear set. This is a staggering difference. The API 613 ratings are consistently the lowest, both for bending and pitting. The highest ratings come from ISO 6336 and ANSI/AGMA 6013, though the inclusion of 6013 may be a bit unfair since it uses stress cycle factors for only 10,000 hours of operation. All other AGMA ratings are fairly consistent.
Figure 3: Overall Rating Another way to consider these results is to look at the ratio of the ratings. The ANSI/AGMA 2001-D04 rating was arbitrarily chosen as the basis of Figures 4 to 6, where each line represents one rating standard. For the pitting ratings, all ratings that use AGMA methods as their basis are consistent. API 613 ratios show a lot more variability (30%) due to factors in the AGMA standards that API 613 does not use. For the surface and case-hardened cases, ISO 6336 ratios show less variability than API, even though the rating method is substantially different from AGMA 2001. The major change comes with a change in material; ISO rates through-hardened steels far lower than AGMA.
This may be due to historical differences, particularly cleanliness, between the through-hardening steels used in Europe and those used in the U.S. Rest of the article is in the Turbomachinery Handbook 2017 John Rinaldo is a senior engineer with Atlas Copco Comptec LLC, a part of Atlas Copco Gas and Process division, where he designs gears for high speed integrally geared centrifugal compressors. For more information, contact [email protected].