Small Volume Unidirectional Captive Displacement Prover


FMD045 Small Volume Prover

Flow Management Devices’ line of Unidirectional Captive Displacement Small Volume Provers (SVPs) provide exceptional accuracy and rangeability. The FMD-045 is equipped with standard 8” ANSI B16.5 flanges on both the inlet and outlet and a flow range capability of up to 4,500 GPM (6,400 BPH, 1,022 M3H). Flow MDs small volume provers are built with quality in mind while providing exceptional performance and field durability, making the FMD-045 an outstanding choice for your application.

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*Max Flow Rate GPM BPH M3H
4,500 6,400 1,022
Displaced Volume Gallons **Liters
Primary Secondary Primary Secondary
35 25 132 95
Std Flange Size Standard Materials of Construction
8” ANSI – 150#, 300#, 600# or 900# 304, 316 - Duplex Stainless Flanges
1200:1 Turndown is typical of normal operations. Turndown ratio can vary significantly depending on installation and process conditions. Actual turndown may be much greater than 1200:1 in some conditions such as water draw, or much less in high pressure, dry product applications such as NGL service.


  • Accuracy: < 0.02% - Exceeds API Standard
  • Performance: Typically 0.005% (Water draw)
  • Uncertainty: 5 psi at max flow rate of each prover (calculated with water)
  • Pressure Drop:


  • Conforms to API 4.2 and API 4.6
  • Galvanized frame per ASTM A123/123M-02
  • Shock mounted isolation pads for independent drive and support
  • 3-point installation for secure mounting on uneven surfaces
  • 2” connection flanges for rapid draining
  • 2” vents with check thermowell and pressure verification ports
  • All wetted parts stainless/PTFE
  • Prover Interface Module (PIM) with advanced features
  • Smooth Belt Drive with clutch
  • Shock mounted Isolation Pads

Flow Management Devices’ goal is 100% customer satisfaction: therefore, we provide the following services at no charge.

  • Final Acceptance Testing (Includes: Water Draw, Hydrostatic & Dielectric Testing)
  • Training in our facility during Final Acceptance Testing
  • Free crating per ISPM-15 (Stationary only)
  • One day onsite startup and training


  • ISO 9001/2008
  • ISO 17025
  • CSA/US Class 1 Div. 1
  • CRN
  • ATEX
  • GOST (Russia)
  • Kazakhstan Metrology

* When sizing a flow meter for this prover, the maximum flow rate should be less than or equal to the maximum rate of the prover. All the FMD Small Volume Provers can operate at the maximum flow rates as specified. Nominal flow rates should not exceed 80% of maximum. All application information should be verified with FMD and will vary due to the meter technology used in each application.

**Please Note: Standard prover volume is in gallons, liters are optional. Prover requires non-standard switchbar for liters. Alternate displaced volumes are available for liters, please contact factory for additional information. Liters are a direct conversion and not indicative of Seraphin can sizes.