A water draw is the procedure for determining the base volume of a pipe prover (also called a small-volume prover or unidirectional prover). Water is drawn through the prover between detector switches and collected in certified volumetric reference vessels — the prover's true volume is computed from that draw.
Lonetti designs complete water draw systems: certified reference vessels (typically 1,000L–5,000L prover tanks), pump skid, valving, detectors, temperature compensation, and the supporting documentation required by API MPMS Ch. 4.9 and OIML R117.
Every system is engineered for the specific pipe prover: diameter, pressure rating, expected base volume, and on-site geometry. Configurations include trailer-mounted, skid-mounted, and permanent installations.
6 properties that define a Lonetti calibration systems.
Specification points worth comparing against any other supplier — accuracy class, material grade, standards compliance, and configurability.
Both methods supported
Volumetric water draw (per API MPMS 4.9.2) and gravimetric (4.9.3) procedures, in one system.
Engineered as a system
Reference vessels, pump, valving, temperature probes, and instrumentation are matched to your prover's geometry.
±0.02% uncertainty
Total system uncertainty as low as ±0.02% with class-0.025 reference vessels and ITS-90 temperature compensation.
Field-mobile configuration
Trailer or skid mounting available — bring traceable calibration to the prover, not the other way around.
Full documentation kit
Procedure documents, calibration certificates, and the math worksheet template required by API.
Detector switch interface
4–20 mA / volt-free contact interfaces to existing pipe prover detector instrumentation.
Built to your spec, certified to ours.
These are the parameters our engineering team needs to start a quote. For a full technical datasheet, request the PDF.
Download full datasheetWhere Lonetti calibration systems go to work.
The same engineering platform serves several distinct use cases. Configuration varies; accuracy class doesn't.
Pipe prover commissioning
Initial base-volume determination on new unidirectional or bidirectional pipe provers.
Periodic recalibration
5-year recalibrations required by API MPMS and many regulatory regimes.
Custody transfer audit
Independent verification of base volumes for fiscal metering audit trails.
Reference traceability
Establishing field-to-lab traceability for petroleum measurement systems.
Workshop, field, and deployment.
Common questions.
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