共查询到19条相似文献,搜索用时 109 毫秒
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针对中大口径供水管路应用旋启式止回阀和单阀瓣蝶式缓冲止回阀存在的问题,根据水利学防止水锤发生的原理,介绍了双阀瓣蝶式缓冲止回阀设计计算,动作原理,结构特点,主要零部件的材料及其适用范围。 相似文献
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调节阀是改变流体流量的装置。我厂通过引进先进技术 ,对调节阀阀瓣的形线进行了最佳设计 ,制造了锻钢调节阀 ,并通过试验得到了流体的流量特性。1 特性锻钢调节阀由组合阀门和流量控制标尺组成。阀门手轮旋转一周 ,标尺指针位移 1 %刻度。任何需要的开启调量 ,都可以通过旋转手轮达到。该阀阀瓣为单瓣抛物线形及V形缺口型。此结构可以确保阀门开启全程中流体按比例流过 ,达到最佳可控性。有 1个V形缺口的称为双瓣式阀瓣。有 2个V形缺口的称为 4瓣式阀瓣。阀座堆焊STL硬质合金 ,阀瓣经过表面硬化 ,因此密封副耐磨、耐腐蚀和耐冲刷。… 相似文献
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根据新型安全阀柔性阀瓣技术,对柔性阀瓣进行了数值模拟和试验研究,首次全面探讨了柔性阀瓣的性能,并与传统刚性阀瓣进行若干比较。通过对密封面接触压力进行数值分析发现,相同情况下,由于柔性阀瓣密封面最大接触压力总是大于刚性阀瓣,因此,柔性阀瓣具有更好的密封性能。试验测试表明,相同情况下,柔性阀瓣的整定压力一般低于刚性阀瓣;而且柔性阀瓣可以降低系统刚度,吸收冲击变形能,使系统抗冲击和抗疲劳能力提高,对保障系统稳定运行有利。 相似文献
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为了保证核电截止阀阀瓣堆焊钴基的焊接质量,有效地提高阀瓣堆焊的焊接一次合格率,对核电截止阀阀瓣堆焊钴基的材料特性、焊接特性进行了工艺研究,并分析了核电截止阀阀瓣堆焊钴基最常见的焊接缺陷类型及其成因。通过对核电截止阀阀瓣堆焊焊接缺陷的成因机理进行分析,并结合阀瓣制造过程中各工序的质量控制要求,从工艺的角度,增加了焊后后热和保温的工艺要求,并改进了阀瓣焊接坡口的基面尺寸结构。从质量的角度,严格控制阀瓣堆焊前焊接坡口以及堆焊后焊缝的外观、尺寸以及无损要求;严格控制阀瓣堆焊的层间温度以及堆焊层厚度。通过这些工艺质量措施的实施,可以有效地提高核电截止阀阀瓣堆焊钴基的焊接质量,降低阀瓣堆焊的返工率。 相似文献
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高性能止回阀结构设计的分析研究 总被引:5,自引:0,他引:5
对各种上回阀结构进行了分析对比,通过图解法和阀瓣运动规律分析,寻找出缩短蝶极开关周期,提高关闭速度,减小或预防水锤压力,减小流阻和阀瓣惯性,提高密封性能的方法。 相似文献
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通过对38in.150磅级(DN950mm,PN2.0MPa)蝶阀蝶板的有限元分析,介绍了有限元分析法在加强筋布置方面的应用。 相似文献
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介绍了海水淡化的主要工艺方法。根据不同的淡化工艺及其系统对阀门的特殊要求,给出了低温多效蒸馏法(MED)淡化工艺用蝶阀的结构形式和蝶板材料的选择方法。 相似文献
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长寿可靠型连杆式切断蝶阀是一种长寿、可靠、安全、高效的中高温气体切断蝶阀,在高炉炼铁系统中用作煤气、空气或烟气管道的切断阀门,应用范围越来越广泛,逐步取代了笨重的闸阀。主要介绍了长寿可靠型连杆式切断蝶阀新的设计理念和结构优化设计方案,对蝶阀四杆机构运动轨迹进行了研究分析,提出了密封补偿机理研究分析理论,优化了密封副设计和材质选择。还介绍了长寿可靠型连杆式切断蝶阀寿命试验及其结果,为连杆式切断蝶阀的工作状况、实际性能等各方面的研究提供了试验数据支撑,对阀门结构优化设计提供了依据。寿命试验对比测量了纳米材料复合电镀自润滑轴套与普通铜基自润滑轴套磨损量,为深入研究长寿可靠型连杆式切断蝶阀长寿安全可靠免维护性能提供了试验条件和技术支撑。 相似文献
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针对嘉利特多级输油泵中的平衡盘磨损快,寿命短的问题,进行了调查,分析研究,找出问题的原因是平衡套的回油间隙偏小,没有完全平衡轴向力,故平衡盘的磨损快,并提出针对性的改进措施,很好地平衡了泵轴向力,延长了泵平衡盘的使用寿命,减少了泵的维修。 相似文献
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Investigation of the mechanical behavior of a flexible solid metal seal for a cryogenic butterfly valve 总被引:1,自引:0,他引:1
Ahn Jun Tae Lee Kyung Chul Lee Kwon Hee Han Seung Ho 《Journal of Mechanical Science and Technology》2011,25(9):2393-2400
Seat tightness at the fully shut position should be a consideration in the development of a butterfly valve for use in a liquefied
natural gas (LNG) vessel. A flexible solid metal seal offers sufficient tightness of the butterfly valve and meets the specifications
for cryogenic temperature. In the present study, characteristics for a cryogenic butterfly valve, such as the flow coefficient
and the pressure loss coefficient, were estimated by numerical fluid analysis carried out to simulate 3-D flow and to study
performance as it was affected by the opening angles of the valve disc. A design criterion to ensure the seat tightness of
the butterfly valve at the fully shut position was proposed, in which the contact pressure between the metal seal and the
valve disc would be compared with the fluid pressure. Numerical structural analysis showed that the contact pressure can be
calculated by simulation of the frictional contact behavior on the surface of the metal seal and the valve disc. As a result,
an adequate flexibility of the metal seal and the valve disc was required in order to accomplish a contact pressure that would
be high enough to satisfy the seat tightness requirement. Under cryogenic temperature, thermal shrinkage caused the metal
seal to adhere closely to the valve disc periphery at both sides and raised the contact pressure to a relatively high value,
though there was no contact across a small area at the center position, which is susceptible to leakage. An additional displacement
of the metal seal and the valve disc appeared at an operating fluid pressure of 6.9 bar and produced sufficient contact pressure
at the no-contact area. This was verified by experimental leakage tests performed at room and cryogenic temperatures. 相似文献
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F. J. Ía Garc de Blas A. Romn C. de Miguel F. Longo R. Muelas A. Agüero 《Lubrication Science》2004,11(2):103-111
High‐temperature‐resistant self‐lubricating coatings are needed in space vehicles for components that operate at high temperatures and/or under vacuum. Thick composite lubricant coatings containing quasicrystalline alloys as the hard phase for wear resistance can be deposited by a thermal spray technique. The coatings also contain lubricating materials (silver and BaF2 CaF2 eutectic) and NiCr as the tough component. This paper describes the vacuum tribological properties of TH103, a coating of this type, with a very good microstructural quality. The coating was deposited by high‐velocity oxygen fuel spraying and tested under vacuum using a pin‐on‐disc tribometer. Different loads, linear speeds, and pin materials were studied. The pin scars and disc wear tracks were characterised using a combination of scanning electron microscopy and energy dispersive spectrometry. A minimum mean steady friction coefficient of 0.32 was obtained when employing an X750 Ni superalloy pin in vacuum conditions under 10 N load and 15 cm/s linear speed, showing moderate wear of the disc and low wear of the pin. 相似文献