Oil Industry Flowmeters
Sensor/ Transmitter to ASME/BASEEFA Approvals
High Pressure Intrinsically Safe Sensor System
For Pelton Wheel & Helical Screw Flowmeters
No magnetic 'drag' is imposed on the rotor
Highest pressure rating systems tested to 11,400 barg, 165,300 psi (Pressure limited only by test jig leakage); Lloyd's Register witnessed
Sensor housing and pick-up all 316 Stainless Steel. Liquid seal retained for field change of pick-up cartridge
Certification of Design
Many purchasers seek approval of flowmeters to the code ASME B31.3. We can meet this requirement for the manufacture of our flowmeters. For Pelton Wheel Flow Meters the highest pressure design comprises of a body with a bolted-on cap which resembles a blank flange. The sensor system is attached to the meter cap and includes an in-service replaceable pickup or reed-switch. For Helical Screw meters the sensor system is attached directly to the meter body.
The Sensor Concept & Operating Pressure
The sensor outer shell is fixed to the flowmeter and has a field-replaceable internal pick-up. For the highest pressure version, the outer sensor shell is domed to form a pressure-resisting 'window' between the pick-up and the meter rotor. As a rigorous method of appraisal, Lloyds Register have verified the sensor design via ASME VIII Division 1: 1998 Subsection UG-101(m) burst-testing procedures. Many Lloyd's Register witnessed tests were performed with various materials and no samples failed. For the highest pressure design and using a cross- referenced but uncalibrated solid state sensor a 11,400 barg, 165,300 psi witnessed test was carried out, limited only by test jig leakage. This reconciles to a design pressure of 2,280 barg, 33,060 psi at 20 °C using a safety factor of five times. The inset picture is of a typical domed sensor end as used in this test. Only minor deformation occurred at 11,400 barg noting that the objective of the test was to crush and burst it.
Later tests for ASME B31.3 appraisal were limited by the necessity of using a test gauge with traceable calibration. The maximum traceable pressure was 10,345 barg, 150,000 psi. Taking a safety factor of five times a Maximum Allowable Working Pressure of 2020 bar, 30,000 psi at 50°C was certified based on actual material properties with traceable test pressure.
The exact features of the sensor dome as tested are incorporated in our high pressure sensor system. This ensures that the certified Maximum Allowable Working Pressures in Lloyd's Register plan appraisals can be used for production sensor assemblies.
I.S. Transmitter Assembly - Isolated Protection and IP68 Rated Enclosure
I.S. encapsulated transmitter electronics with secure 3 mA
Seawater-resistant Naval brass BS2870 CZ112 or 316 Stainless Steel Enclosure
Transmitter pre-amplifier in enclosure with 'O'-ring seal IP68 to 20m submersion
Quick Release Assembly with Adjustable Orientation
IP68 Integral Terminations Enclosure with M20 or M25 gland entry
I.S. Certification
Litre Meter are licensed by EECS (Electrical Equipment Certification Service) for the manufacture of an Intrinsically Safe sensor and transmitter system certified by BASEEFA (the British Approval Service for Electrical Equipment in Flammable Atmospheres). It is approved to the very high standard EEx ia IIc T5 to EN50 020 and to EN50 014. The certificate number is Ex 86B2104. The complete installation certification for the flowmeter and isolating protection devices is also to EEx ia IIc T5 to the European Standard BS 5501: Part 9: 1982 EN50 039. The BASEEFA number is Ex 862105. Protection devices are galvanic isolators (isolated voltage repeater not requiring an IS earth) and alternatively MTL or Stahl zener barriers. Installation can be Zone 0 hazardous areas for up to 135°C service or less as limited by the 'T' rating of the hazardous area. Further details are in the Litre Meter Pelton Wheel Flowmeter catalogue.
IP68 Seawater-resistant Naval Brass or 316 Stainless Steel Transmitter Enclosure
The IP68 rated enclosure has two compartments each with an O-ring sealed lid. One houses the Intrinsically Safe encapsulated transmitter pre-amplifier electronics. This is easily removable and can be exchanged in service. The second compartment is a terminations enclosure with screw terminals and gland entry.
The O-ring seals are re- usable assuring that the full submersion protection can be maintained in usage.
The enclosure is orientation adjustable and with quick-release for easy sensor maintenance.
Our Products
VFF Rotary Piston
LMX Pelton Wheel
Sierra Mass Gas Flowmeter
Helical Screw