Standard Practice for Ammonia Colorimetric Leak Testing
|Publication Date:||15 June 2012|
This test method covers the testing of large single- and double-walled tanks, pressure and vacuum vessels, laminated, lined- or double-walled parts, complex piping systems, flexible containers (such as aircraft fuel tanks), glass-to-metal seals in hybrid packages, and systems that inherently contain or will contain ammonia (such as large tonnage refrigeration systems and fertilizer storage systems).
This method can be used on piping, valves and containers with welded, fitted, or laminated sections that can be sealed at their ends or between their outer and inner walls and that are designed for internal pressures of 34.5 kPa [5 psig] or greater.
Basic procedures are described based on the type of inspection used. These procedures should be limited to finding leakage indications of 4.5 3 10−12 mol/s [1 3 10−7 Std cm 3/s]2 or larger.
Units-The values stated in Std cm3/s or mol/s are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2 The gas temperature is referenced to 0°C. To convert to another gas reference temperature, Tref, multiply the leak rate by (T ref + 273)/273.