PE80焊制管件的承压性能试验分析

根据相关标准以及国内外企业、行业协会的相关资料，对焊制管件的焊制原理进行了介绍；同时对热熔焊制管件的承压性能进行了试验分析和说明。     

聚乙烯焊制管件的焊制工艺

介绍聚乙烯管道用聚乙烯焊制管件的焊制设备和工艺，分析了焊制工艺的几个重要工艺参数，讨论了焊制聚乙烯管件的质量问题及解决办法。     

塑料热板焊的过程分析研究

在塑料热板焊的加热周期里,塑料热熔,并在压力下溢出流动。热熔体的流出量与各工艺参数之间有一个明确的对应关系。该关系式对于设计加热工艺,保证焊接成品的尺寸精度有重要的应用价值。在加热时装置进给量限制器,能更好地发挥加热效率,保证工艺质量。在热板焊的焊接周期里,通过热熔体的流变分析可以定量地确定焊区内的二维流速分布。这对于了解塑料在焊缝中的取向、结晶等过程,将是一个重要的基础。     

聚乙烯管材热熔对接焊冲击性能的研究

应用仪器化冲击试验机对聚乙烯热熔对接焊的冲击性能进行了测试，并对几种实际焊接情况进行了分析。结果表明，冲击试验可以作为评价热熔焊接品质的有效方法；工程中应避免PE100、PE80与PE63的焊接；当被焊管材的标准尺寸比（SDR）不 同时，焊接部位的冲击性能大幅度下降。     

GB／T14383-2008《锻制承插焊和螺纹管件》修订的主要技术内容

介绍了GB／T14383-2008《锻制承插焊和螺纹管件》修订的主要技术内容。新版国标在承插孔径和产品力学性能检验等方面进行了修订，以适应管道现场安装情况，保证管件在压力管道系统中的安全使用。     

塑料压力管道热熔对接自动焊机的研制

塑料压力管道热熔对接焊的工艺参数随管道尺寸和环境条件的不同而不同，同时还受人为因素的影响，因此笔者开发出了利用80C196单片机控制的塑料压力管道热熔对接自动焊机，提高焊接质量。本文还分析了塑料压力管道热熔对接焊的基本原理，并详细地介绍了热熔对接焊机的基本组成部分以及各部分的主要功能和实现方法。     

聚乙烯管材的连接方法和技术

为充分发挥聚乙烯（PE）管材的先进性，经济性和安全性，对PE管材的各种连接方法进行了广泛的研究。介绍了PE管材的热熔对接焊，电热熔焊，热熔承插焊，鞍形/侧壁熔焊，以及钢塑过渡接头连接方法和技术，并对热熔对接焊和电热熔焊作了较深入的探讨，同时进一步分析了不同塑料管材间的焊接方法。     

塑料压力管道的焊接方法及其发展动向

介绍了两种工程上广泛采用的焊接方法：热熔对接焊和电熔焊,并对两种方法的焊接过程和控制参数等进行了详细地阐述。对这两种方法的优缺点进行了比较,并分析了塑料压力管道焊接技术的发展现状以及我国在该领域的发展动向。     

热熔焊接工艺参数对聚乙烯管道力学性能的影响

聚乙烯（PE）管道在天然气运输中应用广泛，热熔焊接是连接PE管道的主要方式之一，焊接工艺参数影响热熔接头以及管道整体的性能。文章以焊接温度、加热时间和焊接压力等工艺参数作为主要影响因素，设计正交试验，制备不同的热熔接头拉伸试样，对比分析其抗拉性能。通过数值模拟得到带卷边热熔接头拉伸试样的本构模型。结果表明：焊接温度、加热时间和焊接压力使PE管道的抗拉性能先增高后降低，焊接温度和加热时间对热熔接头的抗拉性能影响显著。PE管道热熔接头的抗拉性能比基材好。载荷-位移曲线与实验曲线较吻合。基于有限元分析和Kwon聚合物本构模型可得到PE管道热熔焊接接头准确的本构关系。     

钢骨架塑料复合管电热熔管件慢速开裂性能研究与分析

通过对钢骨架塑料复合管电热熔管件慢速开裂性能进行研究和分析,进一步掌握该产品质量控制途径,提高技术研发水平。     

Analysis of Effect of Pressure and Heat on Mechanical Characteristics of Butt Fusion Welding of Polyethylene Pipes

The butt fusion process is one of the most effective processes in welding polyethylene pipes. The heating stage is the most important step in this process. In this investigation, while the main objective was to reduce the final bead's size of the weld, 9 different experiments with different heat and pressure conditions and equal timing for each heating stage were defined. Numerical modeling of Finite Element Method (FEM) of the heating process was carried out in the computer software considering governing physical conditions in the weld to determine heat distribution as well as primary bead geometry. Subsequently, the model was compared with results from experimentations. Cross-cut of the formed primary beads at the end of the heating process were prepared and compared with results from the model. To review final quality of the weld and its mechanical characteristics, all samples were welded under equal pressure conditions. Cross-sections of beads formed at the final stage as well as some samples for tension test and impact test from all welded areas were prepared according to standard for determination of mechanical characteristics and then compared with each other. From mechanical strength perspective, the weld formed in 210°C and 0.18 MPa pressure demonstrated higher values. However, impact strength in the weld formed in 180°C was higher. By reducing pressure in a specified heating process, value of impact energy required to break the piece was reduced. Mechanical strength in heating condition 240°C was lower than all other cases. As for geometry of the formed bead; its size in 180°C and 0.03 MPa pressure in the first stage of the heating process was smaller than other cases.     

塑料热板焊接传热的解析模型

对塑料热板焊接传热进行了探讨，给出简化的物理模型，并转化为双区域计算及熔化热数学模型(即Stefan Neumann问题)，同时做出解答。然后通过算例，应用所建立的数学模型计算出温度分布曲线及加热时间，并与通过实测得出的温度分布曲线及加热时间进行比较和讨论。结果表明，采用此数学模型计算得出的温度分布曲线与实测曲线基本符合，计算得出的加热时间值与实测加热时间值符合良好。     

Structure and aging in the welded bonds of PP- homopolymer with PP- copolymer (PP-R)

The present study deals with changes of welded material of pipes and fittings (isotactic polypropylene homo and copolymer PP-R grey pigmented) during the standardized internal pressure tests, which are commonly used for these products. Technical welding of polyolefines causes characteristic structures, which depend on the natural of the welded material and the welding conditions. In this investigation both the transition of material in the welding seam and the changes of internal stresses during internal pressure tests at 95°C until 18.100h test time were examined. The methods we used were Differential calorimetry of think layers, Polarization- and Electron microscopy, Fluorescence spectroscopy with extreme high local resolution. The effects of decomposition of the macromolecules in the welded samples during the internal pressure tests will be described in a separate paper (1). The internal pressure tests at 95O C cause a recrystallization and an increase of the particle size in the structure of the welding seam and in the structure of the welded parts themselves. Under the above described testing conditions the orientations and internal stresses initiated by the welding procedure will relaxe influenced by heat. However the creep effects that occur in the material when exposed to pressure introduce new internal stresses. It could be shown that in perfectly welded parts a continuous transition from PP to PPCO occurs, which did not change after long time application of internal pressure tests.     

全焊接板式换热器应力分析及评定

利用ANSYS软件建立了全焊接板式换热器管侧集合箱的有限元模型,通过有限元分析得到模型的应力大小和分布。并对管侧集合箱进行了应力等效线性化处理,分解得出均布薄膜应力和线性弯曲应力,继而根据有关标准对应力校核线所在的部位进行了应力分类,并给出了应力强度评定结果,为全焊接板式换热器的设计与制造提供参考。     

工业管道对焊管件的压力设计

对焊管件压力设计采用应力校核方法,也可用承压(削弱)系数的形式表达,后者更为实用。     

Development of pyrotechnic compounds for heat treating welded joints

Results are provided for a study of heating annular welded joints in steel pipes where the temperature gradient in the weld is provided by heating the pipe with various types of pyrotechnic compounds. An estimate is made of the nature of burning of compounds and their heat emission. It is shown that the level of residual stresses in a pipe after pyrotechnic treatment of a welded joint may be considerably reduced compared with the original condition.Chelyabinsk. Translated from Fizika Goreniya i Vzryva, Vol. 27, No. 4, pp. 73–79, July–August, 1991.     

Numerical Simulation of Fluid Flow and Heat Transfer in Thermoplates

A thermoplate is a heat transfer device consisting of two metallic sheets that are spot‐welded according to an appropriate pattern over the whole surface area whereas the edges – except for connecting tubes – are continuously seam‐welded. By applying a hydro‐form technique, a channel having a complex geometry is established between the sheets. Such heat transfer devices are encountered in several areas of cooling and heating techniques and process technology, e.g. as condensers or evaporators. The objective of the described investigations was to numerically obtain the optimal geometry of the thermoplate with respect to heat transfer of the inside fluid that passes through the channel as a single phase. The numerical experiments show that the heat transfer potential of the thermoplate having a staggered arrangement of welding spots is markedly higher than that of a common flat channel, particularly at larger Reynolds numbers. The variations of the geometrical parameters show the potential for the heat transfer improvement in comparison to a corresponding parallel plate channel.     

PVC-U管件专用料的研制

介绍了PVC—U管件专用料的研制过程,采用S-700作为基体PVC树脂,采用铅盐系列作为配方的稳定体系,合理调整内外润滑剂构成润滑体系,用ACR-401作为冲击改性剂。测试结果表明：该PVC管件专用料具有良好的力学性能、成型加工性和热稳定性,管件性能达到相关技术标准要求。     

Sintering behavior of SiO2 aerogel composites reinforced by mullite fibers via in-situ rapid heating TEM observations

The direct in situ TEM imaging method is adopted to investigate the sintering behavior of SiO₂ aerogels during the rapid heating process. The structural evolution of SiO₂ aerogels and composites at different times during the heat treatment process are further investigated via SEM, FT-IR, BET and XRD. The results indicate that the shrinkage of the SiO₂ aerogels and composites primarily occurs during the initial stage of the heating process (within 20 min) with the shrinkage primarily linked to the fusion of small aerogel particles at high temperatures. The aerogel structure then stabilizes with no further shrinkage observed as the heating process continues. The heat treatment process only promotes the space rearrangement and fusion of small aerogel particles with no observed changes to the amorphous structure of the aerogels, and the small-sized particles fusion was the main causes for the structural evolution of SiO₂ aerogels and composites under rapid heating condition.     

热能表示值误差检定的测量不确定度评定

热能表属于强制检定的计量器具,其准确与否直接关系到千家万户和供热商的切身利益。国家加强了对热能表等计量器具使用环节的计量监督管理,强化了对热能表安装使用前首次检定的监督管理,加快了热能表等供热计量器具体系建设步伐,各级计量技术机构都在积极筹建热能表检定装置的计量标准,为供热计量监督提供了技术保障。介绍了测量方法及原理、不确定度的评定,提出了在热能表检定过程中,要有流量、温度和计算器的检定,还要有热量的总量检定;在示值不确定度评定中,各部分要分别评定。