Cloud Point — EN 23015 / ASTM D2500 / CFPP EN 116

What Is Cloud Point?

The cloud point is the temperature at which paraffin crystals become visible in a cooled fuel and the product becomes cloudy. The sample is cooled in a controlled manner and the temperature at which the first turbidity is observed is recorded. It is used together with the cold filter plugging point (CFPP) to evaluate the cold behavior of the fuel.

Purpose of Cloud Point

The aim is to determine the temperature at which the fuel begins to decompose into paraffin in the cold. Below this temperature, crystals can begin to clog the filters.

Which Products Is Cloud Point Applied To?

Diesel and biodiesel blends
Heating fuels
Jet fuel (with freezing point)
Crude oil and intermediate products
Marine distillate fuels

In Which Sectors Is Cloud Point Used?

Oil & GasPetrokimyaEnergyAutomotiveMaritime

Standards Related to Cloud Point

TS EN 23015 / ISO 3015 (cloud point)
ASTM D2500 (cloud point)
TS EN 116 (cold filter plugging point — CFPP)
ASTM D5773 (automatic method)

Cloud Point Conditions

Cooling rate: Controlled cooling defined in the standard
Observation: Manual visual observation or automatic optical detection
Sample clarity: The sample should initially be clear; water creates turbidity and distorts the result
FAME etkisi: Biodiesel content changes clouding behavior

Equipment for Cloud Point

Cloud point cooling bath
Automatic cloud point device
CFPP device
Kalibreli termometreler

Sample Requirements for Cloud Point

Sampling determines the validity of the result in fuel analysis: ISO 3170 (manual) and ISO 3171 (automatic in-line) define the sampling rules. The sample must be taken into a clean container of a suitable material, filled with no air gap, and kept cold for volatile products.
The sample must be clear and anhydrous.
If FAME rate is known, it should be reported
The sample should not be heated before the experiment.

Duration of Cloud Point

Due to controlled cooling, the experiment takes several hours. When cloud point and CFPP are desired together, the duration increases.

Cloud Point Procedure

1Verify that the sample is clear and free of water.
2It is filled into the test tube at a defined level.
3It is cooled at a controlled rate.
4Turbidity is observed at defined levels.
5The initial cloud temperature is recorded.
6If necessary, CFPP test is also applied.

Cloud Point Acceptance Criteria

The acceptance criterion comes from the relevant product specification and varies by season, market and class. Specification versions are updated; the limit values in force for your product are confirmed from the specification text at the quotation stage.

Evaluation of Results

The cloud point indicates the beginning of crystal formation, and CFPP indicates the point where the problem of passing through the filter begins. Specifications often define limits via CFPP; Cloud point is used to evaluate storage and tank behavior. Turbidity from water produces incorrect results.

Cloud Point Report

Sample description and FAME content
Standard and method applied
cloud point
CFPP and pour point results if available
Comparison with specification limit

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

Fuel and LPG market technical regulations (EPDK)
EU 2009/30/EC (fuel quality directive)
Communiqués on the placing of lubricating oils on the market

Petroleum, Fuel and Oil Analysis — What Does This Testing Field Cover?

The section below describes the field that the Cloud Point test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Petroleum, fuel and oil analysis determines whether a fluid meets its specification and how it behaves in use. Standards in this field consist largely of ASTM and EN publications, with a separate method defined for each parameter.

What distinguishes this family is that product specifications are written as PARAMETER LISTS. Specifications such as EN 590 (diesel), EN 228 (petrol), EN 14214 (biodiesel) and ISO 8217 (marine fuels) state for each parameter both the limit and the method by which that limit is to be measured. If the method changes the result may change too; the specification therefore binds the method as well, and the use of an "equivalent method" is possible only where the specification allows it.

On the fuel side, parameters describe three different properties of the product. Physical properties (density, viscosity, distillation curve, pour point, cloud point) determine pumpability and cold weather behaviour. Combustion properties (cetane number, octane number, calorific value) indicate performance in the engine. Contaminant and stability parameters (sulphur, water, sediment, oxidation stability, copper strip corrosion) affect both emissions and storage life.

Oil analysis is carried out for two different purposes and the two must not be confused. Analysis of NEW oil verifies the conformity of the product to its specification: viscosity index, additive content, flash point. Analysis of USED oil, by contrast, is done to read the condition of the machine — elemental analysis shows wear metals (iron, copper, chromium, aluminium), water and fuel contamination point to leaks, and oxidation and acid number determine the remaining life of the oil.

Used oil analysis is therefore a PREDICTIVE MAINTENANCE tool. The trend of samples taken at regular intervals is followed; it is the trend rather than a single result that is meaningful. Iron levels climbing over the course of months allow intervention before a failure occurs.

Marine fuels are the most active sub-body of the field. The global tightening of sulphur limits has brought new blended fuels onto the market; for these fuels stability, compatibility (whether two fuels form deposits when mixed) and catalytic fines content have become critical parameters.

Sampling is part of the result in this family too. A sample taken from the bottom of a tank shows different water and sediment content from one taken from the upper level; in commercial deliveries the sampling point and method are set by contract.

Method groups in this field

Physical properties
Density (oscillating U-tube and hydrometer), kinematic viscosity, distillation, pour and cloud point, flash point.
Combustion properties
Cetane number and cetane index, research and motor octane number, calorific value.
Sulphur and elements
Sulphur by UV fluorescence and XRF; elemental analysis and additive content by ICP.
Stability and corrosion
Oxidation stability, copper strip corrosion, water and sediment, filter blocking tendency.
Composition analysis
Boiling range distribution by gas chromatography, hydrocarbon types (FIA), benzene and aromatics content, fatty acid methyl ester content.
Used oil
Wear metals, contamination (water, fuel, soot), oxidation, acid and base number, change in viscosity.

Commonly confused in this field

The specification binds the method as well; a result measured by a different method may not be accepted for specification conformity.
A single result on used oil is not meaningful; the decision is made on the trend.
The sampling point determines the result; the tank bottom and the upper level show different water and sediment.
The cetane index is a calculated value and is not the same thing as a measured cetane number.
Fuels blended with biodiesel behave differently in terms of storage life and microbial growth; classical diesel parameters are not sufficient.
Mixing marine fuels from different sources can cause deposits; compatibility is assessed separately.

Which decisions these results support

Conformity of a fuel lot to specification and commercial delivery
Predictive maintenance decisions based on used oil analysis
Determining parameters for customs and tax classification
Quality verification after storage, blending and transport
Compliance with sulphur limits under emissions legislation

Related Tests

Frequently Asked Questions About Cloud Point

Does the cold flow additive lower the cloud point?

It usually does not drop; The additives improve CFPP by inhibiting the growth and coalescence of crystals. Therefore, while the cloud point remains high in additive fuel, CFPP can drop significantly.