Krohne Flowmeters | Custody Transfer LNG Ship Loading & Unloading

Published 15 Jun 2020

Process Measurement Instruments – Flow, Temperature, Level & Pressure Measurement

KROHNE Flow Meters

Process Instrumentation for Industrial, Hazardous Area & Explosive Atmopheres

Ultrasonic Flow Measurement

KROHNE flowmeters and measurement instruments provide accurate and reliable measurement of industrial liquids, gases and other media (including emulsions, corrosive liquids and gases) with a range of low/high flow rates.

KROHNE is a world-leading manufacturer and supplier of solutions in industrial and explosive atmosphere process instrumentation – with over 30 worldwide approvals for hazardous area gas and dust Zones including ATEX, IECEx, usFMc, NEPSI, INMETRO, KGS, GOST-R and PESO/CCOE. The range of flowmeters manufactured by KROHNE incorporates multiple explosion proof and protection concepts – including IS (Intrinsically Safe) and Ex d (Flameproof) for flow measurement and metering in the hazardous area industries.

Flowmeters by KROHNE | the world-leading manufacturer and supplier of solutions in industrial and hazardous area process instrumentation: flow meters, level meters, temperature meters and pressure measurement.

Background

Bahía de Bizkaia Gas (BBG) operates a plant for the reception, storage, regasification and loading of Liquefied Natural Gas (LNG) in the port of Bilbao, Spain. Only recently has the storage capacity been increased up to 450,000 m³ (15,891,600 ft³).

In this way, the company is able to receive larger LNG carriers as well as to load LNG carrier ships quickly and efficiently. The jetty can accept vessels of 270,000 m (9,534,960 ft³) storage capacity. The terminal has a maximum gas send-out rate of 800,000 Nm³/ h (498,442 SCFM).

Flow Measurement requirements

BBG were searching for Coriolis mass flowmeters to accurately and reliably measure LNG and BOG with flow rates ranging from 15…186 t/h. Due to the nature of the LNG application, it was critical that the meters were CT approved and conformed to Measuring Instruments Directive (MID) MI-005 for liquids other than water

Safety is a high priority for BBG which meant the meters required ATEX approval for hazardous environments. They were also required to integrate with a flow computer for CT metering.

KROHNE Solution

KROHNE delivered a complete custody transfer cryogenic system as part of a ship loading system approved according to MID 2014 /32/ EU. The OPTIMASS 6400 F mass flowmeter offered a solution for custody transfer loading and unloading of LNG. The KROHNE device features a twin V-shaped measuring tube made of stainless steel (316L). It was supplied in nominal size DN 150.

Another high accuracy (MI-002 approved) OPTIMASS 6400 flowmeter (DN 100) was also included to measure BOG produced by the loading process as it was returned to storage. In addition, KROHNE also provided the SUMMIT 8800, a digital flow computer for CT measurement. The flow computer transfers all measurement data to the distributed control system (DCS) via Modbus RS-485.

Measuring system (MID MI-005, 2014/32/EU) for ship loading of cryogenic liquids as suggested by KROHNE 1 LNG tank; 2 Pumps; 3 Valves; 4 OPTIMASS 6400 (MI-005 flowmeter); 5 OPTIMASS 6400 (master meter); 6 Pressure transmitter; 7 Temperature sensor; 8 Circulation line; 9 Pressure gauge; 10 Ship loading; 11 LNG tanker; 12 Line with boil-off gas (BOG); 13 OPTIMASS 6400 (MI-002 gas flowmeter); 14 SUMMIT 8800 flow computer; 15 Distributed control system (DCS)

Customer benefits

BBG benefits from a complete CT system. The OPTIMASS 6400 provides a high accuracy CT measurement of LNG as well as a flow measurement of BOG. Due to its integrated Entrained Gas Management (EGM™), the meter continues to measure even during start-up phase when vapour break out might occur. The EGM™ functionality reduces the cooling time, enabling a faster loading and unloading process. The 2-phase flow diagnostics signal is used to control start/stop.

Using the OPTIMASS 6400 with EGM™ functionality has helped Bahía Bizcaia Gas to considerably increase the accuracy and repeatability of measurement and allowed them to better meet the production quality criteria. KROHNE fully complied with the quality requirements that BBG had for the measurement.

Working together with the main instrumentation vendor KROHNE payed off for the customer. From consultation to project management to the supply of the Coriolis mass flowmeters and the SUMMIT flow computer to the integration of the CT system into the customer’s DCS – everything has been provided from one source.

High accuracy Coriolis mass flow measurement of LNG with a large flowrate
Complete custody transfer (CT) measuring system for cryogenic liquids
Continuous and consistent measurement results from start to finish even in the event of entrained BOG (Boil-off Gas)

KROHNE Flowmeters Used

OPTIMASS 6400 Meter

Hazardous Area Process Instrumentation, Meters & Measurement – KROHNE OPTIMASS 6400

The OPTIMASS 6400 is the standard high performance Coriolis mass flowmeter for the process industry. The twin bent tube meter offers superior performance and high accuracy in virtually any application: From process control in (petro)chemical applications to concentration measurements in the food and beverage industry to custody transfer filling and transport measurements in the oil and gas industry.

Its high-end options also make the OPTIMASS 6400 the optimum device for cryogenic media like Liquefied Natural Gas (LNG) with temperatures down to -200°C / -328°F as well as applications involving high operating temperatures (up to 400°C / 752°F) or pressures (up to 200 barg / 2900 psig).

Twin bent tube design
Entrained Gas Management (EGM^TM): No loss of measurement with gas entrainment in liquid applications
Device commissioning, verification, diagnostics and monitoring via a secure wireless Bluetooth^® connection (<20 m / 65.6 ft)
Fast and completely digital signal processing
Integrated temperature measurement
Optimised flow splitter for minimum pressure loss
High accuracy mass, density and volume flow measurement (optional ±0.05% of MV)
Highest OIML accuracy class of 0.3 for custody transfer (CT)
SIL2/3 capable up to DN200 / 8″
Extensive sensor and process diagnostics (incl. NE 107)
Available in three different sensor materials (incl. Duplex and alloy 22)
Many options (heat tracing, purge port etc.)
Self draining when mounted vertically
Immunity to crosstalk: resistant to installation and process effects
On-site verification of flowmeter with OPTICHECK service tool possible

Hazardous Area Electrical Distributors

Explosive Atmosphere Experts

Thorne & Derrick are Specialist Distributors of Hazardous Area Electrical, HVAC & Process Instrumentation Equipment with IECEx & ATEX Certifications to the onshore and offshore oil, gas, petrochemicals and process industries.

We supply major UK and international infrastructure projects and also MRO (Maintenance, Repair, Operations) requirements for both planned and unplanned plant shutdowns – we react with a rapid response to customer demand to ensure downtime is minimised and reliable Power, Light & Heat is restored or provided.

We distribute Innovative products to manage the planned replacement of legacy equipment conformant with international classifications including ATEX and IECEx.

ATEX Process Instrumentation