330 likes | 465 Views
Workshop: Vacuum Metrology for Industrial Environments 27 June 2013. QUALITATIVE AND QUANTITATIVE METHODS FOR LEAK TESTING. Definition according ASNT. Non-Destructive Testing
E N D
Workshop: Vacuum Metrology for Industrial Environments 27 June 2013 QUALITATIVE AND QUANTITATIVE METHODS FOR LEAK TESTING
Definitionaccording ASNT • Non-DestructiveTesting • “Non-destructive testing is to determine the physical conditions of an object avoiding to compromise the functions for which the object was constructed.” LEAK TESTING: definition Torino, 27 June 2013
LeakTesting Torino, 27 June 2013
The unitofmeasurementofgaseous flow: mbar·L/s Torino, 27 June 2013
The CorrectApproach Torino, 27 June 2013
MethodsforLeak Detection Torino, 27 June 2013
PressureChangeMethod Torino, 27 June 2013
PressureChangeMethod Torino, 27 June 2013
PressureChangeMethod Torino, 27 June 2013
Bubble test Torino, 27 June 2013
Bubble test Torino, 27 June 2013
Bubble Test Application (vacuum) Torino, 27 June 2013
Ultrasonic Detection The directionality of ultrasound is a fundamental characteristic, while the intensity is an inverse function of source-sensor distance. Torino, 27 June 2013
Ultrasonic Detection Torino, 27 June 2013
Ultrasonic Detection Torino, 27 June 2013
for being detected. TracerGases Torino, 27 June 2013
TracerGases:ThermalConductivity These characteristics varies with dependence from molecular size and speed. They can be used with different gas or gas mixtures, since each of them produces a different thermal conductivity respect to the air. Torino, 27 June 2013
TracerGases:ThermalConductivity Torino, 27 June 2013
TracerGases:ThermalConductivity Torino, 27 June 2013
TracersGases: Mass Spectrometry Torino, 27 June 2013
TracersGases: QuartzCapillary In this leak detector, the detection system of the tracer gas (helium) is constituted by a membrane in quartz, permeable only for helium and not other gases present in the atmosphere. Torino, 27 June 2013
He Torino, 27 June 2013
Test Methodswith Mass Spectrometry Torino, 27 June 2013
Test Methodswith Mass Spectrometry Torino, 27 June 2013
Test Methodswith Mass Spectrometry Torino, 27 June 2013
It is firstly possible distinguish two different types for the leak testing: • Leak Detection Methods (QUALITATIVE), generally controlled by operator, with localization of leak: • Method in Water withpressurizedpiece (visualinspection); • MethodwithBubble (soap solution) withpressurizedpiece (visualinspection); • MethodwithUltravioletLampswithpressurizedpiece (visualinspection); • Methodwith Hot Air (visualinspection at infrared); • MethodwithDielectricVariation on plastic components (ionic system at high voltage). Torino, 27 June 2013
B) Leak Detection Method (QUANTITATIVE) withindicationofGood, RejectPiece and valueof leakrate: • Measurementwithpresurized gas (Helium); • Measurement the flow meterof the pressurizedpiece; • Measurementof the pressuredifferentialbetween the pressurizedpiece and the reference sample; • Measurementof the pressure decay of the pressurizedpiece; • Measurement “compliance” ofpressureincrease in vacuumbell. The instrumentation of this type allows you to monitor in time any drifts of quality, if it is applied throughout the production. Torino, 27 June 2013
MetrologicalLaboratory Torino, 27 June 2013
Gas Injection System Pumping System LT-SP-1 Pumping System LT-SP-2 Leak in Calibration PressureGauge LT-TP-1 Mass Spectrometer ReferenceCapillaryLeak ReferenceCapillaryLeak ReferenceCapillaryLeak Scheme of calibration system ReferencePermeationLeak Torino, 27 June 2013
The calibration requires a calibrated device: REFERENCE LEAK Torino, 27 June 2013
JRP14i – Joint Research Project - Work Packages 2 – Optimization of the process of measurement and leak testing in an industrial environment. Torino, 27 June 2013
JRP14i – Joint Research Project - Work Packages 2 – Optimization of the process of measurement and leak testing in an industrial environment. Study and analysis of the main parameters of the leak detector for refrigerants. Manufacturing of Capillary Leak with Gas Refrigerants (respect to atmosphere). Study of the behavior of the flow of Gas Refrigerants through capillary leaks. Torino, 27 June 2013