The “VW 01137 Fluid transport area - Cleaning requirements for coolant transport components” standard, developed by the Volkswagen automotive company , describes the cleaning requirements for components that transport coolant. These components are classified into four types according to the table provided in the standard:
As general requirements, the different cleanliness requirements should be taken from the relevant component performance specifications and drawings. The required cleanliness values should not be exceeded.
The components must be free of contaminants after cleaning by the manufacturer until assembly. To ensure this, a transport protection device according to the VW 50157 standard must be selected.
Sampling of components to verify that the cleaning requirements are met is carried out after the entire production process is completed. The cleaning check is carried out on individual parts or assemblies that are ready for assembly or delivery.
The requirements have been determined as follows:
The fluoride limit of 70 mg/l must not be exceeded throughout the cooling circuit. When a fluorine containing flux is used in heat exchangers through which the coolant flows, contamination caused by this flux must be limited and monitored to ensure that the above-mentioned limit is not exceeded. The fluoride concentration and particle residue testing for the relevant heat exchanger is carried out in accordance with the PV 3678 standard.
The coolant side must not exceed the applicable limits for the permissible fluoride concentration in the rinse solution and the gravimetric total particle residue content in the rinse solution, taking into account the cooler/radiator design and the respective type.
The fluoride concentration is determined according to the PV 3678 standard and then each heat exchanger is categorized according to the relevant type. The specifications of the highest possible category for the relevant heat exchanger type should be used.
In order to account for the soldering of the cooler/radiator pipes on the tube sheet, the solder seam length in heat exchangers with folded tube design is calculated according to the formula or calculation examples given in the standard.
For heat exchangers with stacked multilayer design, the calculation of the surface area on the coolant side is done according to the formula or calculation examples given in the standard.
Heat exchangers manufactured using chloride-containing fluidizing agents and the oxygen-acetylene brazing method must undergo special consideration. After subsequent production cleaning of the heat exchangers, the chloride content on the coolant-carrying component surfaces must comply with the chemical specifications described in standard TL 82403. Additional specifications must be based on the system requirements in accordance with standard TL 52541.
It must be ensured that all coolant-carrying component surfaces are free from residues of the process fluids used, e.g. paste, grease and oil (hydrocarbons). Process fluids that come into contact with coolant-carrying component surfaces must be removed without leaving any residue during the manufacturing or assembly process.
For engine-mounted parts, target cleanliness values, requirements according to the VW 01134 standard and component-specific standards, e.g. the PV 3347 standard for main engine components, the PV 3336 standard for hoses, lines and circuit parts, and the PV 3678 standard for heat exchangers apply.
The following terms are used as general descriptions for the particle types evaluated in the target values table:
Examples of abrasive particles: sand, corundum, residues from abrasives, silicates, oxides, minerals and ceramics, steels, irons, hard coating materials such as anti-wear coatings, polyamide plastics (glass fibre reinforced), glass fibres.
Fibres shall be measured using their effective length. Fibres are considered to be particles for which the ratio of their effective length to the maximum inscribed circle is at least 20. The maximum width measured as the maximum inscribed circle shall not exceed 50 µm.
Component cleanliness is assessed by means of particle size and type (morphology). The number of particles should be specified in size categories according to ISO 16232. To determine morphology, at least the largest dimension of a particle (particle length) in µm should be determined and assessed. If possible, the particle width should be specified.
Target cleanliness values for individual components and assemblies are given in the table provided in the standard. Functionally critical particles should have a value of no more than 600 µm.
Our organization, which has been trying to support businesses from every sector with its wide range of testing, measurement, analysis and evaluation studies for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services are also provided to businesses in accordance with the "VW 01137 Liquid transport area - Cleaning requirements for refrigerant transport components" standard.
To get an appointment, to get more detailed information or to request an evaluation, you can ask us to fill in our form and reach you.
