Double suction pump in the open pipe wall thickness is less than 4mm should be used for gas welding; the wall thickness is greater than or equal to 4mm should be used for welding. The welding layer (Times) the number of tube wall thickness and width of weld and welding is generally 1 times. Welding 1-3 times. The physical and chemical properties of the welding rod shall conform to the requirements. Welding rod should be dry before welding, welding mouth should be clear brush clean; welding current size should be appropriate, otherwise the current is too easy to weld, the current is too small, not easy to weld penetration. Multi layer welding, the first time with a thin electrode, second times, third times with a rough electrode.
2.Flange connection :
Between the flange opening in double suction pump pipeline should be provided for the thickness of rubber pad 2-5mm, or with white oil impregnated asbestos rope gasket, adjusting washer for installation position on the washer generally leave a handle. When the first with gasket on the flange is coated with a layer of white oil, then the gasket rightly placed between the two flanges, not allowed deviation. After the center line and the slope of the line are in line with the design requirements, the line is stable, and then tighten the bolt. Tighten the bolt should be up and down, left and right alternately, so as to avoid the unbalanced flange disc and the pipeline connection is not tight.
3.Socket connection :
Double suction pump plug in the pipeline laying, usually against trench slope, pipeline socket pipe socket forward, will clean up, insert laid socket cast iron pipe should be 4-8mm of axial clearance, to meet the needs of the expansion pipe. Socket ring gap should be uniform, with oil hemp gap, each ring shall be overlapped each other and Ma rope, compaction matter, oil filling depth of the tight rope socket depth 1/3. Outside the mouth with asbestos cement or expansive cement packing, the depth is about the interface depth of the 1/2-2/3, to hit the real packing layer