This article is about Automatic Tank Gauging ATG Level Transmitters Material Selection Criteria & Design For Level Measurement of Instrumentation and Control Systems as per International Codes and standards for Commercial Buildings, Plants and Refinery Projects.
ATG Level Transmitters Material Selection Criteria & Design
Material Receiving General Checklist for Instrumentation & Control
Purchase Order and Instrument specification sheet criteria shall be confirmed and compared with instrument stainless steel tags / labels and nameplates, and shipment checked for damage, prior to acceptance of the shipment
Verify that all the instruments are from technically acceptable vendors (Attachment 1).
“Displacement level transmitters may be used for liquid level ranges up
to and including 1,830 mm. Use of this technology shall be limited to
non-viscous process fluids with low concentration of solids.
Displacement transmitters shall be considered for a specific application
only if GWR or differential pressure level devices are not suitable.”
“Maintenance Access Requirements:
Sufficient access space above the tank in the X-Y-Z planes shall be provided to facilitate easy removal of the gauge. These dimensions should be in accordance with the vendor’s recommendations.”
“Product Temperature Measurement:
Permanently installed, multiple spot temperature elements shall be used whenever the functional specification requires automatic computation of Gross Standard Volume (GSV) or Net Standard Volume (NSV). The design and installation shall be per API MPMS 7, “”Temperature Determination.”””
“Local Indicators:
An electronic local digital indicator shall be provided at the grade level. The indicator shall display the liquid level in meters-cm-mm or in ft-in-16th graduations and the product temperature when applicable, in user configurable units. The local indicator shall be installed 1.4 m above grade level.”
“Hazardous Area Classification:
RTG equipment installed in classified areas shall meet the listing/certification requirements specified in SAES-P-100 and in the NEC.”
“Intrinsic Accuracy:
For high accuracy applications, the laboratory tested accuracy of the gauge shall be equal to or better than ± 1 mm over the entire range of the RTG. Vendors shall provide certification from a recognized international agency, such as the Dutch Nederland Meetinstituut (NMI) or the German Physikalisch-Technische Bundesanstalt (PTB), to support their claims.
For general service, the laboratory tested accuracy of the gauge shall be equal to or better than ± 3 mm over the entire range of the RTG. Vendors shall provide certified test data to support their claims.”
“Safety Requirements:
The RTG, during normal operation, bench testing or field service, shall not generate microwave power levels hazardous to humans. The maximum power level shall not exceed 2 milliwatts. The RTG shall have approval from the Federal Communication Commission (FCC, USA) and the Saudi Arabian Standards Organization (SASO). The vendor shall provide certification documentation to Saudi Aramco, upon request.
International Codes and Standards for ATG Level Transmitters Material
- Flow Nozzle Material Selection Criteria Design & Flow Measurement
- Venturi Tube Material Selection Criteria Design & Flow Measurement
3. SAES-J-002 – Technically acceptable instruments, 23 June 2008
4. SAES-J-300 – Level, 27 February 2007
5. SAES-B-057 – Safety Requirements: Refrigerated and Pressure Storage Vessels, 29 June 2005
1. Attachment 1: Tank Gauging Technically Acceptable Instruments – SAES-J-002.
2. Attachment 2: Liquid level Gauge Glasses Instrument
