Klass.-Nr. 8K B1 6
The English translation is believed to be accurate. In case of discrepancies the German version shall govern.
Checking for Impurities
Preface This test specification is used in sample and series monitoring tests. It was written with the aid of DIN 8905-1 and DIN 8964-1. Changes The following changes have been made as compared to the November 1987 issue: ? Sections 1.1, 1.2 and 2.3.1 extended ? Figure 1 revised Previous Issues First issue: 02.79 Last change: 11.87
This test specification is used to determine the impurities rinsed from lines (e.g. fuel lines, brake lines, etc) and circuit parts (e.g. evaporators, radiators, etc). 1.2 Requirements (deviation acc. to drawing)
Cleanness of the Interior The lines shall be free of residues from drawing oil, drawing compound, rust, scale, chips or other solid/liquid processing aids. The soluble and insoluble floatable residue produced by washing out the lines with solvents acc. to section 2.1 must not exceed the following limit values (relative to the inner surface area):
? ? ?
Total foreign matter Insoluble matter Soluble matter
≤ 100 mg/m 2 ≤ 60 mg/m 2 ≤ 40 mg/m 2
(test acc. to section 2.3.1) (test acc. to section 2.3.2)
The following limit values apply specifically for brake lines:
Total foreign matter Insoluble matter Particle size Blackening of filter Soluble matter
≤ 30 mg/m 2 ≤ 10 mg/m 2 (test acc. to section 2.3.1) ≤ 20 ?m Discoloration no greater than RAL 9007 gray aluminum ≤ 20 mg/m 2 (test acc. to section 2.3.2)
Continued on pages 2 to 3
orm Fe 41 01.98 Fachverantwortung I/GQ-31 Normung: I/EK-P Gradl Tel: 33904
Vertraulich. Alle Rechte vorbehalten. Weitergabe oder Vervielf?ltigung ohne vorherige schriftliche Zustimmung der Volkswagen AG verboten. Vertragspartner erhalten die Norm nur über die zust?ndige Beschaffungsabteilung.
? VOLKSWAGEN AG - SEAT S.A. - ?KODA AUTO a.s. - AUDI AG
Page 2 PV 3336: 2000-02 2 2.1 Testing of Cleanness Brief Description
Manufacturing and processing methods can leave fatty, oily and solid impurities on the inner surface of the lines and circuit parts. The limit content of these insoluble, floatable and soluble (fatty, oily) residues must be kept low as they can result in physical, chemical and/or mechanical impairment of the overall system. The specimens are washed with a mixture of equal parts acetone (for analysis) and methanol (for analysis) and the mass of the eluted substances determined in order to ascertain the insoluble, floatable residue. 2.2 Test Apparatus
The setup illustrated in Figure 1 is recommended for the test apparatus. It allows the solvent to be drawn into the previously evacuated line or circuit part under turbulence, air bubbles to be avoided and fragments of dirt to be effectively rinsed off. The specimen part to be washed is connected at the lowest point (inlet) to the liquid-flow tube that is immersed in the store tank containing residuefree evaporated solvent. The hose section at the specimen part inlet is equipped with a shutoff cock. The specimen part outlet is connected to the glass receiver tank via a short section of hose. The capacity of the glass receiver tank must be greater than the volume of the specimen part to be washed so that the solvent can be collected. The glass receiver tank is connected by means of a hose to a vacuum pump. A preliminary trial must be carried out to make sure that the hoses are sufficiently resistant to the solvent. The solvent shall, if necessary, be purified by means of distillation.
A to the vacuum pump S Shutoff cock 2 G Shutoff cock 1 H Inlet K Store tank containing solvent
D Outlet F Specimen J Glass receiver tank (vacuum-stable)
PV 3336: 2000-02
Procedure Determination of the Insoluble, Floatable Residue
The test begins with shutoff cock 1 being closed and the specimen part connected to the vacuum pump being evacuated (vacuum ≤ 50 mbar). Shutoff cock 1 is then opened so that the solvent can be taken into the evacuated part. Both shutoff cocks (1 and 2) are closed once the liquid reaches the glass receiver tank and the specimen part is left immersed in the solvent for 10 minutes. The liquid is then suctioned into the receiver tank after the store tank has been removed and the shutoff cock opened. This procedure shall be repeated at least twice. The insoluble residue is separated by means of filtration using a G4 glass filter crucible accurately weighed to within 0.1 mg or a membrane filter with a pore size of 8 ?m, dried at (105 to 110)° C to the point of mass constancy and reweighed after cooling. 2.3.2 Determination of the Soluble Residue
The remaining filtered solvent is transferred to a vessel accurately weighed to within 0.1 mg and the solvent removed by means of distillation in order to determine the soluble residue. The soluble residue can be reweighed after drying in the oven at 105 to 110° C to the point of mass constancy. 2.3.3 Test Scope
The number of parts to be tested shall be selected such that an inner surface of at least 0.5 m 2 is examined.