DOXA GLOBAL LOGISTICS LIMITED specialize in Flow Calibration, Pressure Testing, Hydro Testing And Leak Detection Test, Technical Audit Of Terminal Metering, Metering Consultancy Services, Gas Measurement, Auto Sampling, Quality Assurance And Inspection Service.

FLOW CALIBRATION
FLOW METER CALIBRATION AND REPAIR: Using a high precision Master Meter or Prover Tank the meters be calibrated to a maximum error of + 0.05% and a period of six months for re-calibration. Dynamic SLIP TEST on the meters enables us to predict the mechanical state of meter and permits useful recommendation. When the meter is out of calibration, repair is carried out (with client’s consent) and recalibrated.
PROVER TANK CALIBRATION: We undertake calibration of Prover Tank of all sizes using the Automatic Over flow pipe pipette gravy metrically calibrated to within 0.002% and traceable to international standards. We certify the Prover Tanks at 0.02% accuracy.
SHORE TANK CALIBRATION (VERTICAL, HORIZONTAL BARGES ANDSHIPS)
The necessity of accurate tank calibration becomes particular evident where tanks are used for Stock Control or Custody Transfer Measurements. We undertake calibration of Vertical Storage Tanks using Strapping Method in accordance with API 2551 Bottom volumes for Vertical Tanks can be determined by liquid fill or physical floor survey as requested. Horizontal Tanks, Ship and Barge Tanks can be determined by liquid fill or physical floor survey as requested. Horizontal Tanks, Ship and Barge Tanks are calibrated by Physical Strapping in accordance with API 2551 and 2553 respectively.
ROAD TRUCK CALIBRATION
We undertake calibration of Road Trucks of Petroleum product in the clients’ premises with our high precision Master or at oil Installation if required using the gantry Meters. The calibration can also be done within our premises (flow Lab)
SURFACE AND UNDERGROUND TANK CALIBRATION
These are calibrated by liquid fill method, the most accurate method of calibration using our high precision Master Meters. The liquid fill method in determining incremental volume of the tank takes into account the tilt of the tank underground.
DISPENSING PUMP CALIBRATION
We undertake calibration of petroleum product dispensing pumps using our standard measures traceable to international standards for purpose of precise control of product quantities.
PROVER LOOP CALIBRATION
The foundation of accurate measurement is the confidence of the Prover Loop base volume accuracy. To achieve and maintain accurate results with Flow Meters, it is necessary to have a Measurement Standard against which to check them at frequent regular intervals. If the base volume, which should be calibrated annually, is inaccurate, all subsequent meter factors would lack integrity and cause severe oil losses. In the crude oil terminals where the Measurement Standard is usually the Prover LOOP, it becomes very important and necessary to have them calibrated regularly. We calibrate and certify Prover Loop base volume to 0.02% accuracy. Our staffs have tremendous experience internationally in Prover Loop calibration using the Master Method.
LPG VESSEL CALIBRATION
we also undergo the calibration of LPG vessels and tank within our customer’s premises to ascertain the quality and quantity of the vessels.

PRESSURE TESTING, HYDROTESTING AND LEAK DETECTION TEST
It is necessary to regularly Pressure Test the air receiver tank, surface tank, underground tanks, LPG Vessels and associated pipeline and equipment as recommended by the Department of Petroleum Resources (DPR). Pressure testing enables the identification of leaking Tanks and pipeline. We also undertake repairs and installation for LPG and associated equipment.

1. TECHNICAL VALUATION
It is normal for Oil Producing Companies to demand from their contractors a valuation certificate issued by an independent Inspector like DOXA GLOBAL LOGISTICS LIMITED for all machines and equipment they intend to use on their site. When we are mandated by any company to offer this service on their behalf, a technical evaluation of all the machines to be involved in the contract is conducted. A complete technical evaluation can be carried out on machines like Cranes Compressor, Generators, and Welding Machines etc. to check for Safety, Functionality and specification conformity. These machines are then accordingly, certified after evaluation.
2. TECHNICAL AUDIT OF TERMINAL METERING
This is a specialized service to evaluate the performance of metering systems, in complying with the requirements as laid down in the American Petroleum Institute (API) Measurement Standards. The major components of a Technical Audit are;
1. An evaluation of the condition and design of each metering system with regards to Electronic Condition as per API Standard.
2. Verification of throughout, calculations for Gross Measured Volume Standard Volume Validation of any other Computer Constants and or functions.
3. Calibration checks on Temperature and Pressure Instrumentation.
4. Check on-line sample analysis Procedures and function test auto sampler.
5. Establishing flow curves for meters over the flow range for linearity and repeatability.
6. Verification of Proving calculation and examination of current prover loop calibration Certificate, checking current base volume is in use and correct defect switch pair is selected. Examination of internal condition of Prover.
7. Prove that all critical valves in system are bubble tight when closed under normal operating condition;
function check associated leak detector system. Calibration of instrumentation can also be conducted in the course of the exercise to reduce errors and improve overall measurement uncertainty.
3. METERING CONSULTANCY SERVICES
The scope of consultancy covers:-
i. Design of metering systems.
ii. Review and vetting of metering systems at loading gantry or Crude Oil terminal to ensure their conformity to relevant International codes and Standards for accurate measurement.
iii. Validation of flow measurement equipment.
The validation of Metering System is to make valid the metered volumes of gas condensate on crude oil.
These services calibrate all measuring components of a metering system which includes:
i. Pressure Transmitters,
ii. Temperature Transmitters,
iii. Densitometries,
iv. Flow Computers,
v. Parameter Input,
vi. Calculations
vii. Integration Check over twenty four (24) hours.
The final accuracy of a metering system is then provided for the system as a variable called the uncertainty, which takes into account the sum of all the instruments’ errors used in the system.
4. GAS MEASUREMENT
With assistance of our UK based experts DOXA GLOBAL LOGISTICS LIMITED can Verify the accuracy of optic measurement in accordance with either the AGA 3 or ISO 5167 methods of flow computation.

Our tests would calibrate each component associated with the gas meter run. The orifice plate would be inspected for upstream condition. The differential pressure transmitter would be calibrated using an air dead weight tester. The temperature and pressure transmitter can be calibrated for accurate measurement.
If gas densitometers are in use, a vacuum pump is used to conduct the zero check to confirm the transducer performance. Gas chromatography used for analysis of gas composition can also be verified and or calibration to ensure actual performance.
In conclusion, using a portable computer we would generate a calculation check against the flow computer’s computer values and ascertain the “Uncertainty” limits within which the gas metering systems computes gas measurement in units of volume or mass.
5. AUTO SAMPLING
We offer mobile Auto - sampling equipment to clients on hire to assist and sellers and ship operators to obtain reliable and representative samples during loading or discharge of oil cargoes. It is generally accepted that physically obtained composite samples from ships tanks underestimate the true BS &W and density value. The Auto-sampler allows continuous Flow Proportional sampling at the shipboard manifold that is unbiased and accurate.

QUALITY ASSURANCE AND INSPECTION SERVICES

i. Non-Destructive Testing (NDT)
We are positioned to be a leading organization in NDT services to the petrochemical, refinery, oil & gas, power and steel, water, waste, medical, engineering, construction fabrication, marine and the automotive industrial in Nigeria. Typical services within our scope include:
Dye Penetrant Testing (DPT or DPI)
- Magnetic Particle Testing (MPI)
- Ultrasonic Testing (UT)
- Radiographic Test (RT)
- Metallographic Replication
- Assisted visual inspection and endoscopic inspection of components.
- Eddy current inspection of both Ferro and non ferromagnetic metallurgical evaluation of components.
- Internal oxide (magnetic) layer measurement using ultrasonic methods. These services are offered to assist in the detection and measurement of surface and internal defects using qualified Engineers and Technicians.

CARGO SUPERINTENDENCE

Cargo superintendence is a process of determining the quality and quantity of crude/petroleum products. This involves the fiscalization and de-fiscalization of bulk crude/petroleum products in storage tanks be it land tanks or ship tanks.

THIRD PARTY INSPECTION SERVICES (CONTRACTORS)
These services aims to control the manufacturer or subcontractors premises, the quality of workmanship and conformity of manufactured equipment with the purchase requirement/ specifications, applicable drawings, codes or standards. The level of DOXA GLOBAL LOGISTICS LIMITED involvement would be set in a quality plan mark up and dependent on the equipment and applications. It may include stages or phase inspection, witness testing or final inspection.
We support these services from all phase of delivery from the raw materials through to completion, commissioning and handover.
The relevant components of the service are:
i. Manufacturing Capability Studies
ii. Supplier/Vendors Audits
iii. Development of Vendor Requirement
iv. Shop Inspection

DOCUMENTATION REVIEW AND ADMINISTRATIVE ASSISTANCE:
Material Control and Warehousing Support to Maintain Availability of Essential Parts:

EXPEDITING AND PROJECT MONITORING
This aims at providing the progress of activities with services predetermined time schedule based on critical part network to detect and analyze key area, which might entail delays. The essence of the service is to suggest constructive solutions in order to meet the targets, inform the client of the real situation existing and of all decisions taken to meet schedule.

STATUTORY INSPECTION.
DOXA GLOBAL LOGISTICS LIMITED has certificated engineers, local and expatriates to undertake these inspections. We are approved by Federal Ministry of Labor and Productivity (Factories Act) to engage in these services through our field engineers. We provide statutory inspection service as part of the client’s risk assessment programme and to meet the legal requirements for periodical inspections.
Plant and equipment inspected include:
We provide statutory inspection service as part of the client’s risk assessment programme and to meet the legal requirements for periodical inspections.

Plant and equipment inspected include:
i. Boilers.
ii. Pressure vessel and pressurized systems
iii. Lifting equipment and tackles.
iv. Cranes or excavators
v. Power presses and forklifts
vi. Electrical Installation
vii. Lift and Hosts
viii. Breakdown & condition survey
ix. Generator
x. Technical audits or whole plants and equipment, factories etc.

CONSULTANCY ENGINEERING PROJECTS Through the services of experienced engineers and technicians DOXA GLOBAL LOGISTICS LIMITED are able to assist clients both in Government and Private sectors in realizing their goals on any projects. These include tender preparation, bidder selection process, procurement, field execution, commissioning, and hand over of project deliverables. We will achieve this through our local and expatriate engineers operating locally and engineers in India and South Africa, where we have working agreements with recognized professional engineering companies specialized in our areas on need. We are also capable of recruiting specialist on project specific requirement basis.

COMPARISON OF SHIP BOARD MEASUREMENT AND SHORE TANKS. The importance of ship board measurements, taken immediately after loading or before discharge of crude oil or petroleum product cannot be over emphasized. They are very valuable checks on shore figures, whether these are produced from land tank measurements or metered quantities. In some installation, where cargo loaded are small compared with tank and/ or pipeline capacities, the ship tanks is bound to provide more reliable measurement than any other source because of the complexity of pipeline system at some terminals. In case of disputes regarding product losses, ship figures are always regarded to be more reliable than shore figures. This is due to intricate nature of storage terminals pipeline system which makes it virtually impossible to be sure of the state of all sections of line at any given time.

METROLOGY (INSTRUMENTS CALIBRATION) As a company that prides itself on quality service delivery and customer satisfaction, we are prepared and we do provide solution to calibration requirement for compliance to ISO 9001:2008 and also provide National and International Traceable Calibration and Testing Services to industries backed up with a team of highly qualified and experienced manpower. With our state of the heart laboratory, we provide and delivers efficient quality metrological services.