SPSE flowmeter proving

Foreword
SPSE owns and operates a centralized flowmeter proving facility. This accredited flow laboratory is used for SPSE's own needs and by third parties (mainly manufacturers).

The following text describes how the specific requirements of a flowmeter manufacturer were met in the facility.

Cofrac accredited proving facility
In the early seventies, as no existing facility fulfilled SPSE flowmeters calibration needs, it was decided to invest in an adapted flowmeter calibration laboratory. This choice of a centralized calibration guaranteed a better metrology performance.

This facility, being the only one in the world in such a range of flowrates (up to 4000 m3/h) and viscosities (0.5 to 500 cSt) soon attracted flowmeter users and manufacturers.

To obtain the (recognition of its skills and competences by the international authorities, and offer its clients the best services, SPSE decided to turn to accreditation.

The accreditation gotten in 1998 has just been renewed in January this year till 2012.

Cofrac accreditation guarantees
Being in relation with the manufacturers requires the strict adherence to confidentiality of the personnel performance tests, acceptance inspections, technical expertises and endurance tests in perfectly objective conditions.

The laboratory connects the flowmeters to national standards and carries out primary and periodic calibrations. It also carries out tests or expert studies for all types flowmeters with meter manufacturers.

This accreditation is based on quality and technical process that proves that all calibration meanings are related to national Standards.

SPSE Laboratory guarantees:

• Traceability of results
• Independence
• Confidentiality
• International recognition

Bidirectional calibration
Our client wished to calibrate bi-directional coriolis meters. As a special requirement, he wished the meters to be calibrated in both flow directions without disassembling between testing.

On standard calibration, a bidirectional flowmeter is first calibrated in one flow direction. Then it is disassembled to be turned around and calibrated in the other flow direction. The fluid always goes in the same direction.

For this requirement, it was decided to use the two parallel calibration lines as a valve system allowing the flow direction to be changed in a custom built third line.

The calibration was made with 4 different fluids with a viscosity range from 1cSt up to 100cSt. The results were good in both directions. A master meter was connected in series with the meter to be tested. The master meter was turned around when necessary. The results showed that the intermediary disassembling/assembling didn't have any significant consequences on calibration results.

Therefore, the bidirectional line is only interesting for assembly cost reduction. From a metrology point of view the classical calibration method gives the same overall performance.

Skids or big size flowmeter assembly possibilities

Case story
The calibration facility has got 3 main lines for standard calibration. These lines allow the assembly of meters from 6” up to 24”. This is usually enough for most meter manufacturers or users. A fourth line can be assembled in order to calibrate bidirectional flowmeters.
On a particular case, the manufacturer wished to test a complete metering skid prior to its assembly on an offshore production rig. This skid was to be tested and a calibration certificate issued. The rig contained 3 turbine meters and a prover loop. Our job was to install this in series with our own prover loop, test it up to 2000m3/h with crude oil (expected viscosity: 12cSt).

The metrology work was usual for SPSE. The main problem to be solved was how to install a 3 pieces 40 tons skid 20m long and 10m wide. The available space was there, but the connections to the rig had to be custom built and strong enough to hold the pressure and flows without vibrations and risk of damage. To make the tests, a study of piping connections, soil support, electrical connections and air supply was made by SPSE and the necessary works conducted.

Thanks to the facility possibilities and the internal studies team, we were able to meet the challenge. The skid left our facility in a delay compatible with its departure to its production site. This experience added a new possibility of service to our company and customers.