MassTech International licensees have conducted tank tests up to 85 million litres containing a wide range of liquids from hydrocarbon fuels to caustic soda solution from the American continent to the Far East.
For most AST tank installations, part of the vertical walls are under liquid pressure but are visible so that it is only the integrity of the tank floor that is of interest. Sometimes though, above ground tanks have mounds created round them, not uncommon for military installations, and, in these cases, the test protocol may differ.
Though the tank is required to be out of service and blinded, MassTech International’s technologies do not need the tank to emptied of its product. They are able to overcome the fact that the thermal stability of ASTs is lower than USTs which happens because tanks are exposed to air temperatures directly and are not insulated by the ground and/or ground water. ASTs are more freely vented, and with higher temperatures, are more prone to evaporation losses.
ASTs are often many times larger than USTs affecting the time to complete a test or its precision and increasing the pressures that the sensor needs to accommodate.
Intrinsic safety may be a greater issue in ASTs since hazardous zones are larger. It may be that computers may not be able to be used on site but MassTech International equipment is designed to meet these standards. As with all MassTech International tests, all data is permanently recorded and tests are remotely analysed by dedicated experts.
For AST leak monitoring see under chemical fuses.