Consult about the top screw of floating head heat exchanger
Thread Content
I'm designing a floating head heat exchanger recently. Since it's my first time, I don't quite understand the structural settings in several places. I hope you guys can give me some advice.: 1. Some drawings require jacking screws to fix the flange connection on both sides of the tube sheet. Some people on the Internet say that jacking screws are standard parts, which are screws, but I don’t see them looking like screws in the reference drawing. What kind of structure is it? It is best to provide standards ； 2. Is the purpose of setting up several shouldered double-headed studs to ensure that there is no leakage on the pipe side when the shell side flange connected to the fixed pipe sheet is disassembled? If you can help N, it will be greatly appreciated!
It can be clearly stated that that thing is not a screw! I don’t understand why the original poster calls this thing a top wire?
The jackscrew can be a threaded screw. This is mainly for disassembling the pipe box, I think it doesn't matter if you have it or not. The shoulder stud has a special function, which is to ensure that the shell side is intact when the pipe box is disassembled, or that the pipe box part is in good condition when the shell is dismantled. It just depends on the installation direction of the shoulder studs.
The name of the top thread is something I saw on the drawings and is not my original creation.: ) Thanks for the reply upstairs!
1. It is usually called a jackscrew on the drawing, but it is actually a screw. We usually use eye screws (GB825), which are mainly used for pulling out pipe bundles. 2. Shoulder double-headed studs are mainly used in floating head heat exchangers and U-shaped tube heat exchangers. Its main function should be to prevent the tube sheet from rotating.
It seems that the top screw and the pull tube are not the same thing.
In order to facilitate disassembly, at the connection between the pipe box flange and the tube plate or the connection between the flat cover and the pipe box, a jacking screw should be provided on one side of non-standard parts such as the tube plate or pipe box cover. Top screw diameter and number DN (mm) ≤400 450～600 700～900 1000～1500 1600～2000 D(mm) M16 M16 M20 M22 M24 Number 2 4 4 4 4
Where did you get this data from?
I haven't found any standard that stipulates the specification and quantity of your top screw. Thanks
Top screw: In fact, to put it bluntly, it is a hexagonal head bolt. After being used for a long time, the sealing gasket will stick to the two pieces at both ends of the sealing surface, and it is not suitable to pull it hard, so use a jacking screw to push it to separate the two. Not only for heat exchangers, this thing may also be installed between the equipment flange and the flat cover, or between the manhole and the manhole cover. Anyway, as long as the designer is afraid that it will stick and cannot be opened, he will set it. ； Shoulder studs: Mainly used to support heat exchangers with tube sheets. If you wish to disassemble only one side during disassembly, you need to hold the shouldered studs against a plate on the tube plate that matches the studs to ensure that the other side will not be disassembled. It's a bit confusing, I don't know if I can understand it clearly.
The poster, why not lurk in the relevant company for a year, research and understand it, and then return to the original factory to design? In addition, with your level of design, can you find a buyer?
The poster, why not lurk in the relevant company for a year, research and understand it, and then return to the original factory to design? In addition, with your level of design, can you find a buyer?
This post was last edited by cxd11888 on 2015-6-27 10:39 This jackscrew is mainly used to disassemble the pipe box. When folding the pipe box, first loosen the bolt connecting the pipe box and the tube plate, and then tighten the bolt. The pipe box flange will be forced to separate from the tube plate (strictly speaking, there are gaskets), which serves this purpose. It is shaped like a single-head bolt, except that there is a short section without threads at the end. As for the shoulder bolts mentioned on the 4th floor, they are used in floating head tube heat exchangers, not fixed tube plate heat exchangers. Their structural forms are also different. The top screw is single-headed and the shoulder bolt is double-headed.
It is usually given as a jackscrew in the drawing, but in fact it is a screw. We usually use eye screws (GB825), which are mainly used for pulling out pipe bundles. This is actually wrong. The jackscrew is used to dismantle the pipe box. The pumping tube bundle you mentioned is arranged in the pipe arrangement area on the front of the tube plate, while the jackscrew mentioned by the poster is arranged on the concentric circles of the bolt holes of the pipe box flange.
Agree with the 14th floor: The jacking screw is set on the concentric circle of the bolt hole of the pipe box flange. When disassembling, the flange, gasket and tube plate are tightly sealed. Use the jacking screw to push it up to facilitate disassembly. We usually use eye screws for the pipe bundle you mentioned. The two are different, with different setting locations and different functions.