ASTM E515-11(2022) PDF

Overview

ASTM E515-11(2022), Standard Practice for Leaks Using Bubble Emission Techniques, is a widely recognized non-destructive testing (NDT) method designed to identify and locate leaks in pressure-retaining components and systems. Developed by ASTM International, this standard describes effective procedures for detecting leaks by observing bubble emission in a suitable liquid medium, such as during immersion or liquid application tests.

This leak detection practice is particularly valued in industrial, laboratory, and field environments due to its simplicity and ability to rapidly pinpoint the location of leaks in many types of components. While the standard focuses on qualitative “go/no-go” results, it allows operators to estimate leak size based on observed bubbles. The method described is not intended for accurate measurement of leakage rates but for leak localization and approximate sizing.

Key Topics

• Techniques Described:

  • Immersion Technique: Test specimens are submerged in a liquid, and bubbles indicate the location of leaks. Often used for small sealed containers that can be immersed.
  • Liquid Application (Film) Technique: A liquid film is applied to surfaces or joints; bubbles forming in the film signal a leak. Suitable for larger structures and systems that cannot be immersed.

• Sensitivity and Accuracy:

  • Normal detection limit is approximately 4.5 × 10⁻¹⁰ mol/s (1 × 10⁻⁵ Std cm³/s).
  • Appropriate for finding leaks equal to or greater than this sensitivity.
  • Repeatability and reproducibility are within ±5–10% for leaks at or above the method’s threshold, depending on operator skill.

• Limitations:

  • This practice is not suitable for quantitative leakage rate measurements.
  • Total system leakage assessments require other methods.
  • Proper surface preparation and fluid selection are necessary to minimize false indications.

• Materials and Safety:

  • Ensure compatibility of test fluids with tested materials (metals, plastics, etc.).
  • Evaluate safety, health, and environmental considerations before application, including regulatory compliance.

Applications

• Pressure Vessel and Tank Testing: Used to check welds, seams, and joints in vessels, tanks, and piping systems in industries such as petrochemical, energy, and manufacturing.

• Component Testing: Effective for inspecting small parts, valves, fittings, and assemblies prior to service or after repair, especially when pressure integrity is critical.

• Vacuum Equipment and Storage: Applying the vacuum box variation, the bubble emission technique can identify leaks in storage tanks’ floors and roofs, and in other structures where only one side is accessible.

• Quality Control and Maintenance: Widely used in routine inspections during manufacturing and ongoing maintenance, helping ensure reliability and safety of pressurized systems.

• Aerospace and Defense: Used for leak detection in sensitive systems where loss of containment could present safety or operational hazards.

Related Standards

• ASTM E543: Specification for Agencies Performing Nondestructive Testing - outlines requirements for organizations conducting NDT, complementing the competence expectations of ASTM E515.
• ASTM E479: (Withdrawn) Guide for Preparation of a Leak Testing Specification - provides foundational information on leak test specifications.
• ASTM E1316: Terminology for Nondestructive Examinations - aids in consistent definitions across NDT standards.
• SNT-TC-1A, ANSI/ASNT CP-189, NAS-410: Standards for qualification and certification of NDT personnel, referenced for required operator competence.
• ASME Boiler and Pressure Vessel Code, Section V, Article 10: Additional guidelines on leak testing of pressure components.
• MIL-L-25567D: Specifies properties for leak detection compounds, notably for oxygen systems.

Regular reference to these and associated NDT standards ensures reliable, consistent, and safe application of the bubble emission leak detection techniques in line with international best practices.

Keywords: bubble leak testing, immersion technique, leak location, NDT, pressure vessel inspection, vacuum box leak testing, film solution leak test, non-destructive testing standards, ASTM E515