I would like to ask if there is any difference in the processing costs between the end caps for DN4420 and those for DN4500
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Are these two sizes of end caps generally formed by spinning or using the melon-seed petal method? Could the non-standard size of 4420 result in higher processing costs?
Of course, we need to make the mold again
Are molds also needed for spun caps? ? ?
Most of them are spun; the price for 4420 and 4500 is the same. It’s best to avoid using non-standard nominal diameters
If it’s too large, I guess few companies will have fixed molds; without fixed molds, the manufacturing costs should be pretty similar
For headings of such large diameter, spinning is generally used nowadays. However, when designing the head, the inner diameter is usually set to either 4400 or 4500; it is very rare for the inner diameter of a head to be set at 4420
This post was last edited by wanlirn on 2019-5-11 at 08:48. It’s clear that these are foreign devices using imperial units; it’s best to convert them to domestic standard nominal diameters when bringing them to China. A few days ago we ordered a contract, and the inner diameter indicated in the sketch was 1320, but I was asked to change it to 1300 for the drawings, and the client agreed to that
Processing cost, no difference. For headers of such large diameter, spinning is used. For spinning, there is no difference in processing between these two dimensions.