Design of high-pressure pipelines~~~
Thread Content
This post was last edited by 1016006686 on 2018-11-6 at 09:46. It concerns the design of a pipeline with a pressure of 30MPA and a temperature of 350 degrees. The pump’s outlet is quite large and is of flange type; the diameter of the pump’s outlet pipe is DN50. To connect this to the pipeline, which has an outer diameter of 18 and an inner diameter of 12, should a reducer be used? What type of flange should be employed? Is a butt-welded flange appropriate? Which sealing type for the flange should be chosen? ? ? I don’t quite understand it; I hope an expert can give some guidance~~~ Thank you!
This post was last edited by 3983596_FPPZ on 2018-11-6 at 10:41. A DN50 diameter isn’t considered large either; if it’s reduced to 12, a long reducer will definitely be needed. Reducers of this standard size are not available for purchase, so they have to be made manually. For such temperatures and pressures, it is recommended to use stainless steel wafer butt weld flanges; the flange sealing surface can be of the ring joint (RJ) type, with a metal intermediate sealing ring. Such high-pressure flanges are not common – I have only seen them at CNPC’s drilling and production sites. As for the exact pressure tolerance, it is necessary to consult the flange manufacturer
I also feel that butt welding provides higher pressure resistance. For the steel flanges I checked, it’s acceptable; as for the sealing surfaces, it’s not a problem, but there’s no standard for the gaskets – I don’t know what material to use. There’s no relevant information available. Do you have any ideas?
By flange sealing surface, I mean the grooves between two flanges in which a metal ring is inserted; the material of this metal ring should be the same as that of the flanges, or perhaps slightly softer. What kind of equipment is this? The pressure is so high and the diameter is so small – is it used for hydraulic cutting or jetting?
Based on the description, considering the pressure, temperature, and diameter you mentioned, this should be a testing device. Except for the necessary repairs at the connections to the pumps as mentioned on the 2nd floor, try to avoid using flanges wherever possible; simply welding them in place is sufficient. In such operating conditions, it is actually the studs that are under strain. In the pump section, what people are more interested in is which pump to choose Is it finalized?
The pump is a magnetic pump; for everything other than the pump, I use socket weld pipe fittings. What concerns me at present is the connection at the pump’s outlet – should I use octagonal gaskets or other metal gaskets? I can’t find any relevant standards for this
It can be with RJ flanges, or with tenon-and-socket joints; it’s a high-temperature and high-pressure circuit for use in experiments
It’s really strange – why did you choose a magnetic pump? Is it imported? I haven’t really heard of any magnetic pump manufacturer that can do it. RJ face, octagonal gasket, or elliptical ones are all fine. The standard is easy to find. In your operating conditions, with the frequent alternations between heat and cold, studs are difficult to use and come at a high price. Ordinary high-strength bolts can barely handle it, with not very good results. The gasket and flange will go on the 2nd floor. Given the studs, it is recommended that you use flanges as little as possible and opt for direct welding plus flaw detection.
RJ is no less sealed than mortise and tenon. Bro, what I’m more concerned about is what kind of magnetic pump can withstand a pressure of 30 MPa. Could you give me some recommendations?
I’m sorry for the mistake – it’s a shielded pump, and it’s also imported. I agree with what you and the person in floor 2 said; usually I don’t use bolt connections, preferring welding instead along with flaw detection. But for pumps, it’s not possible to use a flange design, as they can’t be welded directly to the flange... and the diameter doesn’t match either. . Direct welding using reducer pipes is not either very ideal
Shielded pump – my apologies, that was incorrect. I still don’t know the specific parameters of the pump; I only know the outlet size, pressure resistance, heat resistance, etc. Once I have that information, I’ll share it with you