原文：
　       1、情况介绍：河北西柏坡发电有限责任公司装机容量为4×300MW、哈汽N300-16.7/537(538)/537(538)、亚临界、单轴、凝汽式汽轮机，高压缸进汽由两个高压主汽门和六个高压调节门(简称高调门)控制，呼吸阀高调门运行方式根据负荷大小采用单阀或顺序阀。其中#1机组1993年12月投产，历经3次大修、6次小修，末次大修时间为2002年10月。

　　2、事件起因

　　2.1、2002年10月#1机组大修，#4高调门解体发现门杆头部(此处无螺纹，但加工有止动横销孔，ф12mm，L=120mm)发生横向断裂。因止动横销(简称横销)未脱出，所以#4高调门大修前运行稳定，未见异常。

 　　2.2、门杆头断裂的原因分析

　　2.2.1、受力。长期运行中蒸汽对门杆产生轴向周期性激振力针型阀，门杆头部以及连接螺纹部分容易产生疲劳损坏

　　2.2.2、加工工艺。门杆头横销孔采用钻孔后再铰孔加工而成，孔边缘呈现刀锋状，形成典型的应力集中点，裂纹一旦形成后就会迅速发展为断裂。

 　　2.2.3、材质。门杆材质2Cr12NiMoWV，工作于高温下，为增加其抗高温氧化能力，表面进行了特殊的渗氮处理，形成一层厚约0.5mm的氮铁化合物，调节阀 其硬度、耐磨性、抗氧化性大大增加，相应的脆性增大，韧性降低。

 　　2.2.4、装配工艺不当。 　　哈汽厂高调门装配图工艺要求：冷态安装，减压阀门杆旋入导向套内，需要对门杆施加152N*M的扭力，然后装入横销。即要求冷态安装后门杆与导向套完全紧力接触，禁止留有间隙。热态运行时，由于门杆被包在导向套内部，温度高于导向套，其轴向线性膨胀量大于导向套，上述紧力配合依然能得到保证。

         因此门杆热态运行时，门杆受到蒸汽的轴向激振力，此力会直接传递至导向套，从而使门杆的连接螺纹不受激振力的作用，因为连接螺纹部位是更易发生损坏的应力集中点，这样就防止了螺纹的疲劳损坏。实际情况并非如此，6个高调门不同程度存在不符合技术要求的现象，即冷态时回装门杆锻钢阀门，施加152N*M扭力矩后，门杆横销孔与导向套横销孔发生了错位现象，横销无法顺利装入。为了能顺利安装横销，必须要将门杆轻微旋退，如果按照横销孔错位2mm、门杆连接螺纹为M50*2计算，门杆需要退出约0.025mm，即门杆头与导向套存在0.025mm的间隙，这又不符合技术要求的紧力配合。如果检修人员忽视了装配技术要求，图省力而草率地安装，就会留下安全隐患。

“ High pressure regulator valve rod causes and remedies of loose ”是由中国调节阀网提供的国际阀门新闻，译文仅供参考。另外，中国调节阀网还提供相关产品搜索： 手动调节阀、 核用调节阀、 智能调节阀、 自动调节阀、 调节阀价格等。

译文：
          1 Introduction: Hebei Power Generation Co. Ltd. Xibaipo installed capacity of 4 × 300MW, Kazakhstan steam N300-16.7/537 (538) / 537 (538), sub-critical, single axis, condensing steam turbine, high pressure cylinder into the vapor by two high-pressure main steam valve and six high-pressure regulator gate (referred to as a high-profile door) control,Cast Gate, Globe, Check Valves high-profile door operation mode according to load size single valve or sequential valve. One # 1 Unit in December 1993 put into operation, after 3 major repairs, minor repairs 6 times, the last time for overhaul in October 2002. 2, the incidents In October 2.1,2002 overhaul Unit # 1, # 4,Forged Gate, Globe, Check Valves a high-profile breakup found the door lever door head (no thread here, but the process has only fixed horizontal pin hole, ф12mm, L = 120mm) horizontal fracture occurred. Because only fixed cross pin (referred to as cross-selling) does not emerge, so # 4 high-profile overhaul before the stable door, no exceptions. 2.2 Analysis of the door head fracture 2.2.1, force. Long-term operation of the steam door periodic excitation of the axial rod, rod head and the connecting thread some prone to fatigue damage 2.2.2, processing technology. Door with pin hole horizontal drilling head after reaming processed, showing blade-like edge of the hole, forming a typical stress concentration points, it will crack once the rapid development after the formation of fracture. 2.2.3, material. Door rod material 2Cr12NiMoWV, Ball Valveswork in high temperatures, in order to increase its high temperature oxidation, the surface of a special nitriding treatment to form a 0.5mm thick layer of iron compounds of nitrogen, the hardness, wear resistance, oxidation resistance greatly increase, the corresponding increase brittleness, toughness is decreased. 2.2.4, improper assembly process. Ha steam plant assembly drawing high-profile door process requirements: cold install, rod screw guide kit, needs door lever to exert 152N * M of torque, and then loaded cross pin. That is required to install the back door cold pole and power-oriented set of completely tight contact against left gap. Thermal run-time, as the door lever sets are wrapped in direction within the guide sleeve temperature is higher than its linear expansion is greater than the axial direction set, with the tighteningResilient Seated Gate Valves force can still be guaranteed. So the door hot rod run, rod axial vibration by steam power, this force is directly transmitted to the guide sleeve, so that the connecting thread from the door pole excitation effect, because the connecting thread is more likely to have part damage to the stress concentration points, thus preventing fatigue damage thread. Not the case, six high-profile presence in varying degrees the door does not meet the technical requirements, ie the cold state O'clock back loading door Gan, exert 152N * M twisting moment, the door lever cross pin hole and guide pin Kongfashengle Cuo Wei TaoAutomatic Control Valves Wang phenomenon of cross-selling can not be successfully loaded. In order to successfully install the cross pin, a small rotating rod must be returned to the door, if the dislocation cross-pin hole 2mm, the door rod connecting thread is M50 * 2 calculation, the door lever to quit about 0.025mm, the door head and the guide sets exist 0.025 mm gap, which are not in compliance with technical requirements of the tightening force. If the maintenance officer ignored the assembly technology requirements, effort and hasty plans to install, it will be a security risk.

原文来源：http://www.1tiaojiefa.com/

2010-08-16 07:25

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