Section 160.151-31 - Production inspections and tests of inflatable liferafts(a) Production inspections and tests of inflatable liferafts must be carried out in accordance with the procedures for independent laboratory inspection in 46 CFR part 159, subpart 159.007, and with those of this section.(b) Each liferaft approved by the Coast Guard must be identified with unique lot and serial numbers as follows: (1) Each lot must consist of not more than 50 liferafts of the same design and carrying capacity.(2) A new lot must begin whenever the liferafts undergo changes of design, material, production method, or source of supply for any essential component.(3) The manufacturer may use a running-lot system, whereby the fabrication of the individual liferafts of a lot occurs over an extended interval under an irregular schedule. Each running lot must comprise not more than 10 liferafts of the same design and carrying capacity. Each running-lot system must be in accordance with a procedure proposed by the manufacturer and approved by the Commandant.(4) Unless a lot is a running lot, each lot must consist of liferafts produced under a process of continuous production.(c) Among the records required to be retained by the manufacturer under 46 CFR 159.007-13 , are affidavits or invoices from the suppliers identifying all essential materials used in the production of approved liferafts, together with the lot numbers of the liferafts constructed with those materials.(d) Each approved liferaft must pass each of the inspections and tests described in IMO Revised recommendation on testing, as amended by Resolution MSC.295(87), part 2, paragraphs 5.1.3 through 5.1.6 inclusive, (incorporated by reference, see § 160.151-5 of this subpart) and prescribed by paragraphs (e) through (g) of this section. For a davit-launched liferaft, these tests must be preceded by the test described in IMO Revised recommendation on testing, as amended by Resolution MSC.295(87), part 2, paragraph 5.2.(e) The test described in IMO Revised recommendation on testing, as amended by Resolution MSC.295(87), Paragraph 2/5.1.5, must be conducted under the following conditions:(1) The test must last 1 hour, with a maximum allowable pressure drop of 5 percent after compensation for changes in ambient temperature and barometric pressure.(2) For each degree Celsius of rise in temperature, 0.385 kPa must be subtracted from the final pressure reading (0.031 psig per degree Fahrenheit). For each degree Celsius of drop in temperature, 0.385 kPa must be added to the final pressure reading (again, 0.031 psig per degree Fahrenheit).(3) For each mm of mercury of rise in barometric pressure, 0.133 kPa must be added to the final temperature-corrected pressure reading (0.049 psig per 0.1 inch of mercury). For each mm of mercury of drop in barometric pressure, 0.133 kPa must be subtracted from the final temperature-corrected pressure reading (again, 0.049 psig per 0.1 inch of mercury). Corrections for changes in ambient barometric pressure are necessary only if a measuring instrument open to the atmosphere, such as a manometer, is used.(f) One liferaft from each lot of fewer than 30 liferafts, and two from each lot of 30 to 50 liferafts, must pass the test described in IMO Revised recommendation on testing, as amended by Resolution MSC.295(87), part 2, paragraphs 5.1.1 and 5.1.2. If any liferaft fails this test-(1) The reason for the failure must be determined;(2) Each liferaft in the lot must be examined for the defect and repaired if reparable, or scrapped if irreparable; and(3) The lot test must be repeated, including random selection of the liferaft or liferafts to be tested. If any liferafts from the lot have left the place of manufacture, they must be recalled for examination, repair, and testing as necessary; or else the required actions must take place at an approved servicing facility.(g) The manufacturer shall arrange for inspections by an accepted independent laboratory at least once in each calendar quarter in which production of liferafts approved by the Coast Guard takes place. The time and date of each inspection must be selected by the independent laboratory, to occur when completed liferafts are in the manufacturing facility and others are under construction. The manufacturer shall ensure that the inspector from the independent laboratory-(1) Conducts the inspection and witnesses the tests required by paragraph (f) of this section, and further conducts a visual inspection to verify that the liferafts are being made in accordance with the approved plans and the requirements of this subpart;(2) Examines the records of production inspections and tests for liferafts produced since the last inspection by an independent laboratory to verify that each required inspection and test has been carried out satisfactorily;(3) Conducts a design audit on at least one liferaft approved by the Coast Guard each year. If possible, different models of liferafts must be examined in the design audit from year to year. To retain Coast Guard approval, the manufacturer shall demonstrate to the inspector during each design audit that-(i) Each part used in the liferaft matches the part called for by the approved plans;(ii) Each part and subassembly are of the materials and components indicated on the approved plans or their bills of materials; and(iii) Each critical dimension is correct as shown either by measurement or by proper fit and function in the next-higher assembly.(h) The manufacturer must notify the cognizant Officer in Charge, Marine Inspection (OCMI) whenever final production inspections and tests are to be performed so that the OCMI may assign a marine inspector to the factory to witness the applicable tests and to ensure that the quality assurance program of the manufacturer is satisfactory.CGD 85-205, 62 FR 25547, May 9, 1997, as amended by USCG-1998-4442, 63 FR 52192, Sept. 30, 1998; USCG-2010-0048, 76 FR 62999 , Oct. 11, 2011; 77 FR 9865 , Feb. 21, 2012