大尺寸螺絲、螺牙整修

大尺寸螺絲、螺牙整修2019-02-12T07:13:59+00:00

Project Description

煉油/石化廠生產初期大部分著重動態設備(Rotation equipment)的維修。

隨著生產產能增加、靜態設備(塔槽、反應器、熱交換器、管線…)及法蘭面因流蝕(erosion)腐蝕或拆裝次數頻繁、不依規範執行拆裝等,往往造成洩漏增加。

目前國內業界作Cover/法蘭面管理(高壓、高溫設備)著重在:
1.特殊Gasket供應品質檢查、選擇
2.法蘭面旋削(Flange tapping)
3.油壓扭力扳手(Torque wrench)/螺栓拉伸器Bolt tension執行
4.冷熱鎖程序執行
5.打擊扳手強力執行

雖有執行依上述項目,但依大部分重要設備多運轉將近20年,強制冷熱鎖或Torque wrench執行,難免會造成內螺牙因熱應力或應力不佳產生崩壞或潛在性崩壞

目前國內/國外(部分廠商)對內螺牙整修,多採用攻牙整修(Thread of Tapping)
-須以特殊規格機具、攻牙(特殊鑽床及鑽頭作攻牙)
-程序:由於作用功率大,易生高熱,如原材料屬特殊鋼材質,會有金屬晶相異常風險
-攻牙屬強力切削,攻牙後,螺紋並不平滑

群利企業多採國外特殊技術:
提利:攻牙和洗牙並行技術(現場執行)
標準程序:
1.製作與標的物車修相同材質、樣本
2.劃出現場施工按裝程序
3.製作洗牙特殊治具和特殊車邊
4.車間內Demo實際執行標的物樣本程序

洗牙由於順著原內螺紋作車修,故Torque小(可無限大尺寸2”-20”),內螺紋非常平順

群利供應:洗牙後內螺紋會擴大一些(視內損情況),故須重訂製不同尺寸螺栓

Maintenance for rotation equipment at startup stage.

The more the plants running for processing, the more the leakage happen because of flange erosion and deconstruction.

The services that vendors offer for cover and flange in Taiwan:
1.Specific gasket supply
2.Flange tapping
3.Torque wrench for bolting
4.Hot/cold bolting

However, most of the plants have running for 20 years, and it might cause thread corruption.

Thread of tapping is the mainly thread maintenance that vendors offer.
-Specific tools for thread of tapping are needed
-Strong power will lead to high temperature, and cause metal fatique .
-Irregular whorl caused by strong tapping power

GT mainly applies international technology:
Thread of tapping and milling
Standard operating procedures:
1.Sample design
2.Installation process planning
3.Specific fixture making and machining process planning
4.Practice for above items at factories

Machining by following the whorl, therefore, the torque is neglected.

GT offers various sizes of screw for those deformation parts caused by thread of tapping and milling.