SINCE 1952
Your current location:
Technical support

Selection of fasteners for valve pressure bearing parts and calculation of preload torque

Time of issue:2020-05--28
1. The structure of commonly used fasteners for valves (1) The pitch of threaded fasteners for pressure-bearing parts Metric ordinary threads are the most used mechanical fastening threads for valves. Generally, each metric ordinary thread of nominal diameter has multiple pitch, divided into coarse teeth, fine teeth, and ultra-fine teeth. In HG/T 20613 "Fasteners for Steel Pipe Flanges PN Series", HG/T 20634 "Fasteners for Steel Pipe Flanges CLASS Series", DL-439 "Technical Guidelines for High Temperature Fasteners for Thermal Power Plants", GB/T 12234 "Steel Gate Valves with Studs Connecting Valve Caps for the Petroleum and Natural Gas Industry" In the valve design standards and fastener technical guidelines, the fastener pitch is specified.After analyzing these standards, it is concluded that fasteners with a nominal diameter ≤M27 generally use a coarse thread pitch, and fasteners with a nominal diameter >M27 use a fine thread pitch with a pitch of 3. From this, it can be concluded that when the nominal diameter of the thread is large, a smaller pitch (fine thread) is generally used. This is because fine thread threads have the characteristics of small thread lift angle, strong self-locking ability, small torsional stress when tightening, and large rotation angle when tightening the nut. Easy to control, but the pitch is not as small as possible, and the pitch of ultra-fine teeth is generally more expensive. , Commonly used in precision fit.
查看详情 查看详情
Previous page

Contact us

WeChat public account: Beijing Valve General Factory Co., Ltd.

switchboard: 010-8928 3399

fax:010-8928 3802

Sales hotline:010-8928 3800010-8928 3399转2288

Address: No. 3, Lvhai Road, Pangezhuang Town, Daxing District, Beijing

Learn more


Copyright: Beijing Valve General Factory Co., Ltd.         京ICP备08004565号-2       Powered by   营业执照