Sch 2 para 12 Vessel checks
(1) For each individual type of vessel manufactured, the approved body must carry out the appropriate examinations and tests in order to verify the conformity of the vessel with the type described in the Type examination certificate and with the corresponding requirements of these Regulations. (2) The manufacturer must present the vessels in the form of uniform batches and must take all necessary measures in order that the manufacturing process ensures the uniformity of each batch produced. (3) When a batch is examined, the approved body must ensure that the vessels have been manufactured and checked in accordance with the technical documentation, and must perform a hydrostatic test or a pneumatic test of equivalent effect on each vessel in the batch at a pressure Ph equal to 1.5 times the vessel's design pressure in order to check its strength; the pneumatic test must be subject to acceptance of the test safety procedures by the Secretary of State . (4) In order to examine the weld quality, the approved body must carry out tests on test-pieces taken from, at the choice of the manufacturer, either a production test-piece or from a vessel. The tests must be carried out on longitudinal welds; however, where differing weld techniques are used for longitudinal and circumferential welds, the tests must be repeated on the circumferential welds. (5) For the vessels subject to the experimental methods referred to in paragraph 17 (experimental method) of Schedule 1, these tests on test-pieces must be replaced by a hydrostatic test on five vessels taken at random from each batch in order to check that they conform to the essential safety requirements set out in that paragraph. (6) In the case of accepted batches, the approved body must affix its identification number, or cause that number to be affixed, to each vessel and must draw up a written certificate of conformity relating to the tests carried out. All vessels in the batch may be placed on the market except for those which have not successfully undergone a hydrostatic test or a pneumatic test. (7) If a batch is rejected, the approved body must take appropriate measures to prevent the placing on the market of that batch. In the event of frequent rejection of batches, the approved body may suspend the statistical verification. (8) The manufacturer must be able to supply on request by the relevant authorities the approved body's certificates of conformity referred to in sub-paragraph (6). (9) The approved body must supply the Secretary of State and, on request, other approved bodies, ... with a copy of the inspection report issued by it. (10) The manufacturer must, under the responsibility of the approved body, affix the approved body's identification number during the manufacturing process. (11) In this paragraph, a “batch” of vessels must consist of no more than 3,000 vessels of the model of the same type.