Plate condenser tube bulge welding sequence plate condenser although expansion before welding process can be used, but making use of both at home and abroad show that the first expansion after welding process has more advantages.
From a lot of practical experience, the plate condenser in the design and manufacture, priority should be given first to settle matters later welding process, in the case of pipe material with poor solderability, nozzle can be set aside 10 ~ 15 mm don't bulge area.
Plate condenser for heat treatment after welding, such as expanding the mechanical expansion, the expansion before heat treatment, heat treatment after light bilge again;
Such as using the flexible expansion joint, can heave a can after heat treatment.
In addition, the plate condenser stick expansion roots and the gap between the upper seam in the welding heat, air heat expansion escape from the weld molten pool blowholes affecting the welding quality.
And also need to be fixed nozzle when first bulge, change again after expansion pipe less convenient.
So the plate condenser is generally adopt the method of first expansion after welding.