Regarding plate flat welding flanges and necked butt welding flanges
Thread Content
I would like to ask the experts: With a design temperature of 380 degrees and a design pressure of 0.05 MPa, and the fluid flowing through it being engine exhaust gases, can a PL plate-type butt weld flange be used, or is it necessary to use a WN necked butt weld flange? If a WN necked butt weld flange is used, which standard and pressure class would be the most reasonable and cost-effective choice?
It is recommended to use WN necked butt-weld flanges. There are European and American standards for necked butt-weld flanges. The European standard specifies PN10. For American standards, choose CL150.
Considering cost-effectiveness, it is recommended to use a butt weld flange, which will suffice. 6 kilograms of pressure is more than sufficient. The flange standard recommends JB/T5010-58
At these temperature and pressure conditions, it is considered sufficient to use flanges that meet GB/T9119-2010 PN6 standards; the flanges specified in HG/T20592-2009 are slightly heavier than those per GB/T9119-2010!
I’m amazed to see so many flanges from various standard systems.
It is acceptable to choose the 9119-2010 flat welding flange; PN6 is sufficient.
Given the high temperature, it is recommended to use the ANSI CL150 standard
Simply choosing a flange will do; a butt-welded flange is also an option. However, due to the high temperatures, the pressure rating and type of flange must be matched to those of the gasket used. If reinforced flexible graphite sheets are used as gaskets, and the pressure class of the flange is 10 or higher, a butt-welded flange can be used. Metal wound gaskets should be used, with the flange’s pressure rating being no less than 16; welded neck flanges should be employed for the flanges.