Common piping errors

In the left image, once the flange is removed, the pipelines above have no support

With the valve removed in the left image, the vertical pipeline has no support anymore·~~ The description later on is correct~~~~

This post was last edited by Baoji Chaosheng Titanium Industry on 2018-8-6 at 10:38; the description that follows makes things quite clear. The flange on the left image has been removed. The pipeline above has no support anymore.

Isn’t there a pillar under the pipeline on the left?

Once the valve is removed, it’s left hanging in mid-air

If the pipe above the pipe in the left pipeline is not fixed firmly, and if the pipe slides down a few millimeters after the flange is removed, can the flange still be fitted back in?

It’s just a few centimeters; a little adjustment will do. But the problem is, if it’s a large-diameter pipe... it’s difficult to make adjustments due to its weight

Yes, if the diameter of the pipe opening is relatively large and the weight is high, it’s easy to disassemble, but reinstalling it becomes quite troublesome.

1. The support issue shown in the diagram is the main cause; the fact that the displacement of the valve in one of the vertical pipes is small when it is removed does not mean that the piping system is stable. It is very likely that an external force (such as water hammer) could cause the entire structure to lose its stability. 2. Placing the valve at the base of the pipe outlet helps to maximize the interruption of the continuity of the equipment and pipelines. Otherwise, as shown in Figure 1, there is a low point in the pipeline on the left side of the equipment’s outlet; without a drainage system in place, the liquid accumulated inside the equipment cannot be drained effectively, which poses a safety risk during equipment maintenance. 3. If the pipeline is a heat pipe, installing flanged valves at the equipment’s nozzle can minimize the impact of thermal stresses on the openings in the equipment. If stress is concentrated at the equipment’s nozzle, it will be the flange that leaks first, rather than the short tube or reinforcement plate welded at the base of the equipment’s nozzle. The use of flanged valves in this area can at least maintain the integrity of the equipment in case of an accident, preventing secondary damage caused by the rupture of the equipment’s nozzle.

Legend explanation: When designing supported pipes, it is necessary to consider that equipment with flanges (such as valves), when removed for maintenance, should not affect the pipe supports.