steam boiler dilatation measuring instruments, ZOZEN tells you what is the boiler expansion indicator

The boiler installation is carried out at room temperature. After the boiler is put into operation, all boiler parts will be heated to produce expansion and relative displacement. The thermal expansion will produce huge destructive force during the hot run of the boiler, which sometimes can cause unexpected results. Therefore, the boiler expansion must be handled correctly during the boiler installation to avoid economic losses caused by expansion. This time, ZOZEN will give a detailed introduction to the boiler expansion indicator, a kind of steam boiler dilatation measuring instruments, which can effectively monitor the boiler expansion during operation and detect the problems caused by the boiler expansion in time to avoid the equipment damage.

1.The steam boiler dilatation measuring instruments - expansion indicator: definition

The expansion indicator is used to monitor the expansion of thick-walled pressure vessels such as steam drums and headers during the ignition and pressure boost processes. It can detect the deformation of the evaporation equipment caused by improper ignition and pressure boost or poor installation and maintenance, to prevent cracks and leaks caused by uneven expansion. It is generally installed on the header and steam drum.

2.The steam boiler dilatation measuring instruments - expansion indicator: working principle

The expansion indicator adheres to the principle of thermal expansion and contraction. The dynamic and static separation produces displacement. When the temperature and pressure rise, the heating element will inevitably undergo thermal expansion. In order not to make the heating element to generate greater thermal stress, its expansion can not be hindered, otherwise the heating element will inevitably be deformed or damaged (especially the welded junction). The significance of recording the expansion indicator is to find the place where the expansion is blocked in time when the boiler working condition is affected, and take timely measures to avoid the equipment damage.

The steam boiler dilatation measuring instruments - expansion indicator

3.The steam boiler dilatation measuring instruments - expansion indicator: basic structure

The expansion indicator is the contact-type, two-dimensional or three-dimensional. It adopts the more intuitive ball-type design with less friction, which can reduce the visual error. The pointer can stretch freely. The panel uses the method of electric engraving. The depth of the scale line is 0.01-0.5 mm to prevent wear caused by contact. Because the contacted steel ball can roll freely, the panel is guaranteed not to wear. A scale is drawn on the pointer to make a set of indicators to achieve the three-dimensional scale. Meanwhile, in order to adapt to different environments, it can also be designed and manufactured according to actual requirements. The expansion indicator products are produced in accordance with American ASME standards, German DIN standards, Japanese JIS standards, Chinese GB/Y, JB, SH, HG standards, etc. They are widely used in the petroleum, chemical, pharmaceutical, electric power, aerospace, fire fighting, metallurgy, shipbuilding, gas, urban construction plumbing and environmental protection industries.

4.The steam boiler dilatation measuring instruments - expansion indicator: installation

The dial of the expansion indicator should be firmly welded to a metal structure that does not expand with the furnace body and is convenient for inspection. After installation, the indicator needle should be calibrated to "0" on the dial and the expansion direction should be correct. The expansion indicator needle is a wall-piercing component, so an oval hole should be left on the wall according to the expansion direction of the equipment, and proper sealing should be considered.

The above mentioned makes us have a more in-depth understanding of the function of the expansion indicator, a kind of steam boiler dilatation measuring instruments, which is one of the important indicating instruments to ensure the safe and stable operation of the boiler. Therefore, in the initial stage of boiler installation, we must pay attention to the correct installation and use of the expansion indicator, and pay close attention to the numerical change of the expansion indicator during the operation of the boiler, so as to ensure the safe and stable operation of the boiler.

If you have more question about steam boiler dilatation measuring instruments, welcome to consult ZOZEN Boiler.