Document ID: chunk:federal_register_of_legislation:F2007L04654:body:0:p4
Version: federal_register_of_legislation:F2007L04654
Segment Type: other
Provision Reference: 
Character Range: 8216–11051

glass bead peening, sand blasting etc.). If such mechanical treatment is unavoidable, it should be followed by a light cutting action such as that provided by hand sanding with sharp "wet and dry" papers, well‑lubricated with cleaning solvent of a type described in paragraph 1.3.

2 Application of penetrant

       2.1The method of application of penetrant is not critical and may be by dip, spray, brush or any other method which ensures complete coverage of the surface under inspection.

       2.2The temperature of the surface to which penetrant is applied must be within the range 2-50C unless the penetrant used has been qualified by the manufacturer as being effective outside this temperature range.

       2.3The penetrant must remain in contact with the surface of the part for not less than 20 minutes.

       2.4Where post-emulsification is to be used, the penetrant must be drained from the part in such a way as to ensure that the coating of excess penetrant remaining is of uniform thickness on the surfaces to be inspected.

3 Removal of excess penetrant

       3.1When a solvent remover is used, great care must he taken to avoid overcleaning. A lint-free, clean cloth moistened (not soaked) with the solvent must be used. On no account must the solvent be applied directly to the surface unless it is in a foamed form.

       3.2When a water-washable penetrant is used, excess penetrant must be removed by water spray. The water temperature must be in the range of 10-45C. Detergents must not be used. Whenever possible, washing must be accomplished with a hand‑held nozzle, on a hose, at standard water mains pressure. The water jet should be directed at the surface at a glancing angle and must not be allowed to remain stationary on any part of the surface. Washing must be discontinued immediately the surface is sufficiently free from excess penetrant to provide an acceptable "background" allowing flaw indications to be clearly visible after development.

       3.3If a post-emulsifiable penetrant is used, emulsifier must be applied to the surface before water washing. Application of the emulsifier must be such that all surfaces are evenly covered in 1 operation. Application must be by immersion or by gently flow coating. Emulsifier must not be applied by brush or forceful spray. Draining of parts during emulsification must be effected in such a way as to ensure that the emulsifier remains evenly dispersed over the surface of the part. Emulsification time is critical and must be obtained experimentally by determining the minimum time required for a given part at a given temperature to achieve an acceptable "background" allowing indications to be clearly visible after development. After emulsification, parts must be washed with water as described in paragraph 3.2.

4 Application of