The shortcomings of existing tightness test methods of buried gas pipeline are analyzed, and a tightness test method based on measurement of pipe wall temperature is proposed. The method has the following characteristics: the measured outside pipe wall temperature is converted to the medium temperature inside the pipe according to the empirical formula, so the precision of temperature measurement is improved; the pressure drop inside the pipe is dynamically measured during the test process, and the gas leakage is precisely ascertained; in the light of different measurement ranges of testing pressure meters, the different allowable pressure drop values are used as acceptance criterion of tightness test.

本文就波形膨胀节疲劳分析设计的安全系数及我国有关规范中关于疲劳试验的要求和规定进行了分析探讨,提出了一些问题和建议,供膨胀节工作者参考讨论.

Many buried cracks were founded out in the circle weld seam on the cylinder of a prehydrogenating reactor with non destructive inspection. In order to find out the crack causes, the chemical compounds and mechanical performance of the base layer (SA387Gr11C12) and the compound layer ( SA240TP321) materials were inspected, the heat treatment and weld process parameters of the reactor were analyzed, the sensitive indexes of the weld cracks of the reactor cylinder material were calculated, it was concluded that the major factors of the weld cracks of the cylinder were because of the lack of the high temperature temper insulation time, the high sensitive index of the weld cracks of the reactor cylinder, the low preheating temperature before welding and the weld complicacy of the intermediate layer of the compound steel sheets. Some heat treatment and weld process parameters were proposed for the reference of the same type apparatuses.

本文介绍了在开发大型信息管理系统时,如何在Oracle中创建多个数据库,如何为每个数据库进行优化配置.

通过慢拉伸应力腐蚀试验,研究了16MnR钢在含H2S介质中的应力腐蚀行为,采用均匀设计方法分析了H2S含量、C-含量、温度和pH值等参量对16MnR钢应力腐蚀敏感指数的影响,并对试件微观断口形貌进行了扫描电镜分析.

通过4种合成纤维滤布的强力拉伸试验,测得了滤布在干、湿两种状态下的力学性能指标,得出了不同拉伸速度对滤布断裂强度和断裂伸长率的影响,同时指出当滤布的应力超过屈服点时,会出现应力松驰现象.

以4种常用工业滤布为过滤介质,分别进行了透过空气、清洁水和酞氰蓝染料悬浮液的渗透性试验,测得了滤布的透气阻力、透水阻力和透过悬浮液的过滤介质阻力,并推出了它们之间的关系.通过悬浮液的过滤试验,提出了一种理论预测滤布的颗粒截留能力的方法.