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1.
Korolev I. A. Alekseenko N. N. Porodnov B. T. Sapunov V. A. Savel'ev D. V. 《Measurement Techniques》2003,46(9):865-871
The design of a sylphon bellows sensor and the basic circuits of an LC-generator and of a microprocessor unit are presented. An analytical pressure–frequency conversion function and a special method of adjusting the sensor ensure an error of less than 0.05%. The dynamic range is up to 105. The instruments developed cover the ranges 103, 104, and 105 Pa. 相似文献
2.
Previous work by Li et al. in the area of axial vibrations of bellows dealt with fixed end conditions. However, it is seen on several occasions that bellow ends are welded to a small pipe spool that has a lumped mass such as a valve or an instrument. Hence, the present paper aims at finding out the effect of elastically restrained ends on the axial natural frequencies. The analysis considers finite stiffness axial restraints on the bellows, i.e. solving the set of equations with non-homogeneous boundary conditions. Two bellow specimens are considered for comparison having the same dimensions as taken by Li in his analysis. The transcendental frequency equation deduced is accurate as the first, second and third mode frequencies computed are in close agreement to the ones obtained by Li. 相似文献
3.
According to the characteristics of fluid-structure interaction(FSI) in the process of metal bellows inflating to disperse bomblets,a 3D dynamical FSI model(W model) which describes the interaction between a viscous compressible flow and a structure undergoing large deformationis established.Then the dynamic characteristics of the metal bellows deformation, the changing law of the internal flow field and the motion law of the bombs are acquired.Where the internal pressure and bombs'' moving law are approximate to interior ballistic results, which indicates the W model established reasonably.Besides, considering gaps existing atthe bellows'' tow ends, the dynamical FSI modelcontaining gaps(Y model) is also built.The results of the W and Y models are compared and the results show that the existence of the gaps has little influence to the flow field and the stress distributionin the bellows,but obviously reduces the separation speed of the bomblets about 10%. 相似文献
4.
采用金相显微镜和扫描电镜分析了热力管线中不锈钢 波纹管破裂原因.该波纹管破裂特征与一般环向开裂不同,裂纹沿轴向扩展.分析认为,破裂 属穿晶应力腐蚀.引起应力腐蚀的介质是土壤中的氯化物,而应力则来自环向工作应力和冷 加工残余应力,而环向工作应力起主导作用。 相似文献
5.
6.
在气体绝缘金属封闭开关设备(GIS)中,母线是重要的组成部分。针对母线因温度变化或地基沉降等导致尺寸变化的情况,根据计算模型,以ZF12-126型GIS为例分析了母线波纹管的设置原则,为相关的母线工程设计提供参考。 相似文献
7.
Errors of pressure measurement are considered. The error as a function of the pressure for a vacuum gauge rated at up to 1000
Pa is calculated as an example. It is 0.15 ≤ δp/p ≤ 0.2% over a pressure range of 14 ≤ p ≤ 1000 Pa and it increases hyperbolically
up to 100% with p = 0.01 Pa. The parametric reliability of the instrument and its immunity to an accidental increase in pressure
the atmospheric level is substantiated.
__________
Translated from Izmeritel’naya Tekhnika, No. 9, pp. 37–41, September, 2006. 相似文献
8.
针对当前混凝土圆柱施工工艺中采用木模板时截面尺寸难以保证或者实体观感较差以及采用定型钢模一次性投入过大,施工不方便的问题,通过市场考察以及实际试验操作,提出了采用PVC-U双壁波纹管作为模板材料的施工工艺,保证了工程质量和观感效果,并取得了较好的经济效益。 相似文献
9.
There were three consecutive occurrences of bellows failure in a particular pressure safety valve (PSV) of a petroleum refinery within a time span of one week. The bellows were made of 316L grade austenitic stainless steel, and the PSV was mounted on one of the vessels of vacuum gas oil service in a hydrocracker unit. Metallurgical analysis of the failed bellows revealed that the failure had occurred by stress corrosion cracking (SCC). It was found that the SCC was promoted in the bellows due to the presence of high amount of chloride ions in the operating environment. Studies confirmed that SCC had initiated from the outer surface of the bellows and propagated inwards, resulting in leakage of hydrocarbon from the PSV. The source of chlorine in the environment was identified. It was discovered that SCC in the bellows was caused due to a previous failure in the heavy polynuclear aromatics (HPNA) absorption bed located upstream the process flow line. This failure was due to the presence of high concentrations of chlorine in the granulated activated carbon that was used in the HPNA absorption bed. During the repair of the HPNA bed, there was deposition of carbon soot on the body of the PSV. This carbon soot was the source of chloride ions for SCC to occur in the bellows. Generally, in chloride SCC, crack propagation in 316L SS takes place by transgranular mode. In the present case, however, the crack propagation was predominantly by intergranular mode. The metallurgical factors responsible for this change in micro-mechanism of crack propagation during SCC have been discussed. 相似文献
10.