الوصف

Stainless steel: 304 304 L 316 316 L 321 2520 310, 317, etc. 
Path: DN15-DN1200. 
Wall thickness: SCH5-SCH160. 
The standard: ASME DIN JIS BS GB/T JB SH HG, is as follows: GB/T12459-2017,GB/T13401-2017,ASME B16.9, SH3408, 
SH3409,HG/T21635,DL/T695,SY/T0510, DIN2617. 
Uses: water, beverage, beer, food, petrochemical, nuclear power, machinery, medical equipment, fertilizer, shipbuilding, waterproof treatment, pipeline, etc. 
Packing: wooden cases, cartons. 
Avoid splicing at r of the disc cap, which will reduce the thickness and high stress. 
The weld direction is required to be radial and circumferential only when splicing. 
This requirement may be removed from the large cap in the future. 
The splicing distance should be greater than 3 δ and not less than 100mm (the welding heat affected zone is a high stress zone, and the chemical composition in this area will be burned. 
So avoid the high stress zone, which is related to thickness. 
According to the practical experience, the stress attenuation length is greater than 3 δ and not less than 100mm). 
However, it is difficult for refrigeration equipment to meet this requirement, which has its particularity. 
For the head formed after splicing, the splicing weld shall be tested by 100% ray or ultrasonic wave, and the qualified level shall follow the shell of the equipment. 
Finally, the detection level and proportion of the formed weld are the same as those of the equipment shell, which is a high waste. 
Hemispherical head. 
Hemispherical head. 
Example: if the device shell is 20 per cent tested, III is qualified. 
The stuffy splicing weld and the final weld are also III qualified, and the coefficient of welded joint is 0.85; 
If the device shell is 100 per cent tested, the II is qualified. 
The stuffy splicing weld and the final weld are also II qualified, and the coefficient of the welded joint is 1. 
So stuffy splicing although 100% detection, but the qualification level is not the same, with the equipment shell walk. 
However, attention should be paid to the manufacturing process: 
The right thing to do is: blanking (marking)-small plates assembled into large plates-forming-nondestructive testing. 
If it is wrong to do the test before forming, it can not guarantee the quality of the product after molding. 
That is to say, nondestructive testing refers to the final nondestructive testing.