本欧洲标准规定了符合EN 12953-1规定的外壳锅炉安全系统的限制器（或限制装置）的要求。 限制器（或限制装置）可以是: - “压力设备指令”第1条第2.1.3款中定义的安全附件，需要包括安全逻辑和最终执行器，或 - 安全系统的一个要素，例如，用作“压力设备指令”第1条第2.1.3款所定义的安全附件的一部分的自监控水位传感器。整体锅炉保护功能需要与额外的安全逻辑（如果适用）和最终执行器相关联。 本欧洲标准涵盖了限制器的设计要求和功能能力检查。 有关限幅器（或限制装置）的范围的说明，请参见图A.1

This European Standard specifies requirements for limiters (or limiting devices) which are incorporated into safety systems for shell boilers as defined in EN 12953-1. A limiter (or limiting device) can be either: - a safety accessory as defined in the Pressure Equipment Directive, Article 1, clause 2.1.3, and needs to include the safety logic and final actuator, or - one element of a safety system, for example, a self-monitoring water level sensor used as part of a safety accessory as defined in the Pressure Equipment Directive, Article 1, clause 2.1.3. The overall boiler protection function needs to be provided in association with additional safety logic (where appropriate) and a final actuator. The design requirements and examination of functional capability for the limiters are covered in this European Standard. For an explanation of the extent of the limiter (or limiting device) see Figure A.1.