Radial Load as a Lip Seal Design and Quality Control Factor

1968 ◽  
Vol 90 (2) ◽  
pp. 405-411 ◽  
Author(s):  
W. A. Schmitt
Keyword(s):  
Quality Control ◽  
Working Conditions ◽  
Control Factor ◽  
Radial Load ◽  
Lip Seal ◽  
New Device ◽  
Seal Design

A new device for the measuring of radial load in the laboratory and quality control is described. Equations are derived for the evaluation of the radial load and the influence of materials and seal dimensions on the radial load are shown. Obtainable production tolerances for the radial load of a seal are discussed. Considerable changes of radial load due to working conditions can cause the failure of a seal. More attention should be paid to a thorough consideration of the working conditions before a seal is designed.

How to measure the radial load of radial lip seals

2021 ◽  
Vol 68 (3-4) ◽  
pp. 5-12
Author(s):  
Simon Feldmeth ◽  
Mario Stoll ◽  
Frank Bauer
Keyword(s):  
Practice Guideline ◽  
Best Practice ◽  
Parameter Study ◽  
Radial Load ◽  
Measurement Device ◽  
Lip Seal ◽  
Study Results ◽  
Lip Seals ◽  
German Standard ◽  
The University

The radial load of a radial lip seal indicates how strongly the sealing lip is pressed on the shaft. The radial load significantly affects the function of the seal. The German standard DIN 3761-9 describes the measurement of the radial load according to the split-shaft method but leaves room for interpretation. During the revision of the standard, a parameter study was conducted at the University of Stuttgart. This study analyses the influence of the measurement device, the mandrels and the measuring procedure on the results. Based on the study results, recommendations are derived and summarized in a best-practice guideline, which should enable an appropriate and reproducible measurement of the radial load.

scholarly journals Quality control in oocytes by p63 is based on a spring-loaded activation mechanism on the molecular and cellular level

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Daniel Coutandin ◽  
Christian Osterburg ◽  
Ratnesh Kumar Srivastav ◽  
Manuela Sumyk ◽  
Sebastian Kehrloesser ◽  
...  
Keyword(s):  
Dna Damage ◽  
Quality Control ◽  
Cellular Level ◽  
Activation Mechanism ◽  
Control Factor ◽  
Dna Double Strand Breaks ◽  
High Concentration ◽  
P53 Family ◽  
Strand Breaks ◽  
Induced Apoptosis

Mammalian oocytes are arrested in the dictyate stage of meiotic prophase I for long periods of time, during which the high concentration of the p53 family member TAp63α sensitizes them to DNA damage-induced apoptosis. TAp63α is kept in an inactive and exclusively dimeric state but undergoes rapid phosphorylation-induced tetramerization and concomitant activation upon detection of DNA damage. Here we show that the TAp63α dimer is a kinetically trapped state. Activation follows a spring-loaded mechanism not requiring further translation of other cellular factors in oocytes and is associated with unfolding of the inhibitory structure that blocks the tetramerization interface. Using a combination of biophysical methods as well as cell and ovary culture experiments we explain how TAp63α is kept inactive in the absence of DNA damage but causes rapid oocyte elimination in response to a few DNA double strand breaks thereby acting as the key quality control factor in maternal reproduction.

scholarly journals Spatial quality control bypasses cell-based limitations on proteostasis to promote prion curing

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Courtney L Klaips ◽  
Megan L Hochstrasser ◽  
Christine R Langlois ◽  
Tricia R Serio
Keyword(s):  
Quality Control ◽  
Molecular Chaperone ◽  
Protein Misfolding ◽  
Elevated Temperatures ◽  
Control Factor ◽  
Control Mechanisms ◽  
Cellular Environment ◽  
Effective Activity ◽  
Spatial Quality

The proteostasis network has evolved to support protein folding under normal conditions and to expand this capacity in response to proteotoxic stresses. Nevertheless, many pathogenic states are associated with protein misfolding, revealing in vivo limitations on quality control mechanisms. One contributor to these limitations is the physical characteristics of misfolded proteins, as exemplified by amyloids, which are largely resistant to clearance. However, other limitations imposed by the cellular environment are poorly understood. To identify cell-based restrictions on proteostasis capacity, we determined the mechanism by which thermal stress cures the [PSI+]/Sup35 prion. Remarkably, Sup35 amyloid is disassembled at elevated temperatures by the molecular chaperone Hsp104. This process requires Hsp104 engagement with heat-induced non-prion aggregates in late cell-cycle stage cells, which promotes its asymmetric retention and thereby effective activity. Thus, cell division imposes a potent limitation on proteostasis capacity that can be bypassed by the spatial engagement of a quality control factor.

scholarly journals Phosphorylation of the C-terminal tail of proteasome subunit α7 is required for binding of the proteasome quality control factor Ecm29

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Prashant S. Wani ◽  
Anjana Suppahia ◽  
Xavier Capalla ◽  
Alex Ondracek ◽  
Jeroen Roelofs
Keyword(s):  
Quality Control ◽  
Control Factor ◽  
Proteasome Subunit

scholarly journals A novel UGGT1 and p97-dependent checkpoint for native ectodomains with ionizable intramembrane residue

2015 ◽  
Vol 26 (8) ◽  
pp. 1532-1542 ◽  
Author(s):  
Jessica Merulla ◽  
Tatiana Soldà ◽  
Maurizio Molinari
Keyword(s):  
Quality Control ◽  
Protein Quality ◽  
Structural Defects ◽  
Control Factor ◽  
Loss Of Function ◽  
Functional Protein ◽  
Aaa Atpase ◽  
Golgi Transport ◽  
Defects Identification ◽  
Pharmacologic Inhibition

Only native polypeptides are released from the endoplasmic reticulum (ER) to be transported at the site of activity. Persistently misfolded proteins are retained and eventually selected for ER-associated degradation (ERAD). The paradox of a structure-based protein quality control is that functional polypeptides may be destroyed if they are architecturally unfit. This has health-threatening implications, as shown by the numerous “loss-of-function” proteopathies, but also offers chances to intervene pharmacologically to promote bypassing of the quality control inspection and export of the mutant, yet functional protein. Here we challenged the ER of human cells with four modular glycopolypeptides designed to alert luminal and membrane protein quality checkpoints. Our analysis reveals the unexpected collaboration of the cytosolic AAA-ATPase p97 and the luminal quality control factor UDP-glucose:glycoprotein glucosyltransferase (UGGT1) in a novel, BiP- and CNX-independent checkpoint. This prevents Golgi transport of a chimera with a native ectodomain that passes the luminal quality control scrutiny but displays an intramembrane defect. Given that human proteopathies may result from impaired transport of functional polypeptides with minor structural defects, identification of quality checkpoints and treatments to bypass them as shown here upon silencing or pharmacologic inhibition of UGGT1 or p97 may have important clinical implications.

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