Measurement Solutions Marine & Commodities' Custody Transfers

In manufacturing industries, transportation and receiving raw materials, goods, and liquid substances is a day-to-day job. 

The transferring can be done between tanks and tankers, pipelines, producer to pipelines, producer to ships, or wherever the transferring is needed. 

However, transferring any raw material, liquids, fuel, or physical substances between tanks, tankers, ships, or any other segment requires a proper channel, so all the materials are transported with accurate measurement. 

This is where custody transfer or custody transfer measurement comes in handy.  

In the oil and liquid industry, custody transfer is the transfer of liquid between two parties. Custody transfer or custody transfer measurement is also known as fiscal metering; a name used to describe transactions where fluids are exchanged or transferred between companies. The transfer process can occur through any chain, for example, ships, tanks, or tankers. Whenever the fluids are transmitted from one place to another, custody transfer takes place.  

Custody transfer in the liquid industry does not only involve the transaction of fluid from one place to another, but it also includes accurate fluid measurement before and after the transfer using flow meter devices.

During the process of fluid transfer, custody transfer flow meters are used to measure the mass or volume of the liquid before and after the transfer process to assure accurate measurement of the fluid.  

The major difference between custody transfer and traditional flow meters is that custody transfer is higher in terms of accuracy and repeatability. Therefore, custody transfer is an advanced version of conventional flow meters as it offers highly engineered and accurate flow measurement and transfer applications with the use of metering systems. 

Components of A Custody Transfer: 

A custody transfer point isn’t just a vehicle that transfers liquid, but it is engineered as an entire metering system to perform various functions, for example, transfer and flow measurement of fluid. 

Liquid custody transfer systems consist of the following components/devices: 

  • Flowmeters
  • Meter provers; used for the calibration of meters. Calibration is performed before, during, and after the batch transfer.
  • Flow computers
  • Supporting automation
  • Quality measurement (Sampling and water monitoring system for liquids, online gas chromatography for measuring the energy content of gas)
  • Pressure and temperature transmitters

Flow meters are the essential component of the custody transfer system. Various types of flow meters can be used in the custody transfer of liquid, but each one of them has its own benefits and drawbacks. 

Why Is Accuracy Important In Custody Transfer Measurement? 

The ability of the flowmeter to measure to the nearest or actual value of the flow is termed accuracy. During custody transfer measurements, the accuracy of the meter and measuring system is of utmost importance. 

Because of the large amount of fluids being transferred and the high value of these goods, the measurement system in custody transfer must be highly accurate, properly designed as per the oil industry standards.

Moreover, payment is usually made based on the amount of gas or liquid fluid being transferred. Hence inaccuracy or small measurement errors can easily cause financial loss to the parties.