Pipelines should be marked at least once in each room; at each penetration point in bulkheads and decks, close to each valve and within a distance of 3 - 5m along the length of the pipeline. Local conditions may require more marking due to pipe bends or the close proximity of pipes for different services. Prior to application, pipes should be dust and oil free. The tape should overlap by at least 20mm on the ‘blind side’ of the pipe, however on pipes with an external circumference of over 200mm the tape only needs to cover half the circumference of the pipe.