Section 161.002-4 - General requirements(a) The purpose of fire detection systems is to give warning of the presence of fire in the protected spaces. To meet this end, the basic requirements of these systems are reliability, sturdiness, simplicity of design, ease of servicing, and the ability to withstand shipboard shock and vibration and the adverse effects of sea humidity. All fire detection systems must be designed, constructed, tested, marked, and installed according to the applicable standards as incorporated by reference in § 161.002-1 and 46 CFR chapter I, subchapter J (Electrical Engineering) of this chapter.(b) Approvals for detection systems issued before July 22, 2017 will remain valid until July 22, 2021.(c) Detection systems installed, with a valid approval, before July 22, 2021 may be maintained onboard vessels and repaired as indicated in 46 CFR 76.27-80(d).USCG-2012-0196, 81 FR 48275 , July 22, 2016