前言:这是CSA标准CAN3-M423的第二版，现在是CAN/CSA-M423，耐火液压油。本标准以SI（公制单位）编写，取代了1984年出版的前一版。本标准将液压油分为三类。其原因是认识到目前的技术水平，并允许对油液和油液系统进行升级，以满足耐火性要求。这些类别描述如下:（a）第1类:这些油液是最耐火的在本标准规定的可燃性试验中，耐火且无可测量的火焰持久性。（b） 2类:这些液体不像1类液体那样耐火，但仍符合本标准中规定的可燃性试验（火焰持续时间更长）。 （c） 第3类:这些液体比矿物油具有更高的耐火性，但只需通过本标准中的喷雾可燃性测试即可。它们通常与使用矿物油的系统兼容。本标准是根据省级矿山检查员的要求编制的，旨在涵盖广泛用于采矿机械液压系统的液压油的安全方面的标准。与1984年版M423相比，主要变化如下:（a）第4.3条，流体稳定性:油包水乳液的可接受油分离率已从3%降至2%。（b） 第4.4条，毒性:该条款已扩展，包括关于急性毒性、急性皮肤刺激、急性眼睛刺激、致敏和慢性毒性的详细标准。 （c） 第5.1条，预处理试验:现在仅对非水液压油进行预处理试验。（d） 第5.4.3条，冻融稳定性试验:本试验中完成的暴露循环次数已从两个循环增加到七个循环。范围:1.1本标准涵盖了用于矿山的液压流体的油包水乳液分离的耐火性、毒性和稳定性。1.2本标准涵盖以下类别的流体:（a）第1类——在本标准规定的任何一项可燃性试验中均未显示可测量火焰持久性（即小于1s）的流体；（b） 2类——通过本标准规定的喷雾和灯芯可燃性试验的液体； （c） 3类-通过本标准规定的喷雾点火试验，但可能无法通过灯芯试验的液体。1.3本标准不包括燃烧产物或受到火灾或加热的液压油的热降解产物。注:虽然本标准的目的是为液压油建立合理的耐火等级，但任何液压油都可能在不同于本标准所述的条件下燃烧。

Preface:This is the second edition of CSA Standard CAN3-M423, now CAN/CSA-M423,Fire Resistant Hydraulic Fluids. It is written in SI (metric units and supersedes the previous edition published in 1984.This Standard divides hydraulic fluids into three categories. The reasons for this are to recognize the present state of the art, and to permit upgrading of fluids and fluid systems to meet requirements for fire resistance. The categories are described as follows:(a) Category 1: These fluids are the most fire resistant and show no measurable flame persistence in the flammability tests specified in this Standard.(b) Category 2: These fluids are not as fire resistant as the fluids in Category 1 but still meet the flammability tests (with longer flame persistence) specified in this Standard.(c) Category 3: These fluids are considerably more fire resistant than mineral oils but are only required to pass the spray flammability test in this Standard. They are usually compatible with systems designed to use mineral oil.This Standard has been prepared as a result of a request from the Provincial Inspectors of Mines for a Standard to cover the safety aspects of hydraulic fluids, which are used extensively in the hydraulic systems of mining machinery.The major changes from the 1984 edition of M423 consist of the following:(a) Clause 4.3, Fluid Stability: The acceptable oil separation for water in oil emulsions has been decreased from 3% to 2%.(b) Clause 4.4, Toxicity: This Clause has been expanded to include detailed criteria on acute toxicity, acute skin irritation, acute eye irritation, sensitization, and chronic toxicity.(c) Clause 5.1, Preconditioning Test: The preconditioning test is now to be carried out only on non-aqueous hydraulic fluids.(d) Clause 5.4.3, Freeze-Thaw Stability Test: The number of cycles of exposure completed in this test has been increased from two cycles to seven cycles.Scope:1.1This Standard covers the fire resistance, toxicity, and stability with respect to separation of water-in-oil emulsions of hydraulic fluids intended for use at mines.1.2This Standard covers fluid in the following categories:(a) Category 1 - fluid that shows no measurable flame persistence (ie, less than 1 s) in either of the flammability tests specified in this Standard;(b) Category 2 - fluid that passes both the spray and wick flammability tests specified in this Standard;(c) Category 3 - fluid that passes the spray ignition test specified in this Standard but may not be capable of passing the wick test.1.3This Standard does not cover products of combustion or products of thermal degradation from hydraulic fluids subjected to fire or heating.Note:While the object of this Standard is to establish a reasonable level of fire resistance for hydraulic fluids, it is recognized that any hydraulic fluid may burn under conditions different from those described in this Standard.