BS EN 15612:2020 pdf free.Railway applications – Braking -Brake pipe accelerator.
BS EN 15612 1 Scope This document is applicable to brake pipe accelerators designed to vent the brake pipe of railway vehicles when an emergency braking is initiated, without taking the type of vehicles and track gauge into consideration. This document specifies the requirements for the design, manufacture and testing of brake pipe accelerators.  2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 14478:2017, Railway applications – Braking – Generic vocabulary EN 14601:2005+A1:2010, Railway applications – Straight and angled end cocks for brake pipe and main reservoir pipe EN 15355:2019, Raiway applications – Braking – Distributor valves and distributor-isolating devices EN 45545-2:2013+A1:2015，Railway applications- Fire protection on railway vehicles- Part 2: Requirements for fire behaviour of materials and components EN 50125-1:2014, Railway applications – Environmental conditions for equipment – Part 1: Rolling stock and on-board equipment.4.2.1 General Brake pipe accelerators shall be able to operate with all distributors valves that conform with EN 15355:2019 and all existing brake pipe accelerators that comply with the requirements of this document. The brake pipe accelerator shall be ready to operate when the brake pipe has reached the normal working pressure. The brake pipe accelerator shall operate in response to a defined rapid fall of brake pipe pressure to ensure a continuing rapid fall to below 2,5 bar. 4.2.2 Operating requirements The following operating requirements are defined in relation to the normal working pressure of (5,00土0,05) bar. When an emergency braking occurs, the brake pipe accelerators shall create a sufficiently rapid reduction in brake pipe pressure to ensure the rapid increase in brake cylinder pressure on every vehicle in the train set. When the pressure in the brake pipe has fallen quickly to below 2,5 bar, and within no more than 4 s after the brake pipe accelerator commences operation, the brake pipe accelerator shall stop venting air so that the brake pipe can rapidly be refilled. This requirement shall be proven by testing in accordance with 5.2.4.4. No functional errors shall occur in the operation of the brake pipe accelerator at input pressures of (5,00土1,00) bar. This requirement shall be proven by testing in accordance with 5.2.4.10.BS EN 15612 pdf download.