Nozzle extension length
Thread Content
Specifically speaking, at which point should the extension length of the nozzle reach which specific surface of the flange?
From the outer wall of the cylinder to the first flange sealing surface
There are provisions in 5.3.3 in HG20583.
Check out the French standards or equipment manufacturing standards. They are all marked with legends.
Generally from the outer wall to the flange sealing surface
The extension length of the nozzle from the point where the center line of the nozzle intersects with the outer surface of the cylinder to the flange sealing surface is
Generally, it is to the flange sealing surface to facilitate calculation of the external pipeline length, but the equipment marking method is to the flange outer end surface.
The dimension of the nozzle extension length marked on the drawing is the distance from the outer surface of the cylinder to the sealing end face of the flange. To calculate the length, refer to the dimensions given in each flange standard.
This question is really unique. The extension length of the nozzle is the distance from the outer wall of the cylinder to the flange sealing surface.
There are two reasons why there is such a formulation.: One is the distance between the sealing surface and the screw hole.
There are two reasons why there is such a formulation.: One is the distance from the sealing surface or the distance from the surface that is flush with the screw hole (there is a step between these two surfaces) ； Second, if the flange is FM, does it have anything to do with construction? Although it is only about 2mm, if you consider construction, I think it should be the surface where the measurement is convenient, not the sealing surface!
For details, you can check HG20583-1998, which is very detailed.
1. It is the distance from the sealing surface, not the distance from the surface flush with the screw hole.； 2. If the flange is FM, the surface where the sealing surface is flush with the screw hole should be on the same plane for easy measurement!
It should be the length from the highest point of the outer wall of the cylinder to the sealing surface of the nozzle flange, which is the extension length of the nozzle.