DMS SEALS TECHNOLOGY CO.,LIMITED

DMS Seals - Hydraulic Seals and Oil Ring Seals Manufacturer & Supplier

The Professional Sealing Solution Supplier(O Ring Suppliers & Oil Seal Manufacturers).

Types of failure modes of mechanical seals

by:DMS Seals     2022-02-14


The currently used bellows mechanical seals and their auxiliary systems cause rod seal failures mainly in the following forms:



1. failure caused by loss of elasticity or rupture of bellows: During the use of bellows, the rigidity of the mechanical seal or elasticity of the fire pump will gradually decrease. This phenomenon of elasticity reduction is usually called loss of elasticity. , Experiments and practical applications show that when the loss of elasticity of the bellows exceeds 18% to 20% of the design initial compression, the entire bellows mechanical seal will leak. The metal bellows mechanical rod seal loses no obvious phenomenon when the temperature is lower than 200 ℃, but when it is used at high temperature (over 300 ℃), the pump leaks soon after starting up. Remove the used mechanical seal and measure the NETZSCH mechanical seal. It is found that the height of the metal bellows assembly is reduced by an average of 2 to 3 mm compared with that before installation. The loss of elasticity of the bellows is mainly due to the deformation or the relaxation of the mechanical seal of the stress multi-stage pump. Another situation is that the working medium crystallizes or solidifies in the gap of the bellows, which reduces or loses the deformability of the bellows. Therefore, high temperature and load are the main reasons for the loss of bellows [1]. In addition, in the case of high temperature and the compression of the bellows or the contact specific pressure, the bellows will break; the higher the temperature and the greater the load, the higher the probability of the bellows breaking.



2. failure caused by excessive wear of the graphite ring in the paired friction pair: Usually, when the failed mechanical seal is removed and inspected, it is found that the graphite seal ring is severely worn. Through analysis and experiments, it is found that the specific pressure of the end face of the metal bellows mechanical seal is affected by the effective diameter of the bellows, and the effective diameter changes with the pressure. Due to the excessive pressure, the friction pair is severely rubbed, and the graphite ring is excessively worn and leaked.



3. failure caused by surface thermal cracking of the cemented carbide ring in the paired friction pair: After inspection, it was found that the cemented carbide ring of the sealing friction pair appeared many radial diameters of different thicknesses emanating from the center of the hard surface. Cracks, which are seal failures caused by thermal cracking. The main reasons for hot cracking are the excessive local thermal stress, the difference in the linear expansion coefficients of the cemented carbide ring and the ring seat, whether the surfacing structure is used or the overall structure, the type of flushing fluid in the sealing cooling flushing system, flushing Whether the method and the flow rate are appropriate may cause thermal cracking of the sealing end face.






Chloromethyl



Chloromethylation reaction is an important reaction in organic synthesis. Relevant personnel can conduct research according to different types of chloromethylation reagents, reaction catalysts with different activities, reaction media with different polarities, and phase transfer catalysis technology. A brief introduction to the different chloromethylation reagents is given below.



Chloromethylation is a widely used reaction. After the CH2CL group of the introduced compound can be converted into CH2OH, CHO, CH2CN, CHNH2, CH, CH2R and other groups, a series of Derivatives, so as to realize the transformation of real substances and improve the performance of products, so it can be prepared by using a variety of different chloromethylation reagents and different catalysts.



Aldehydes, paraformaldehyde and hydrochloric acid: The classic chloromethylation reaction is based on mono-HCHO\-(HCHO), mono(HCHO) and HCL as chloromethylation reagents, although they are less reactive and the reaction time Factory, the productive rate is not high, but they are low in price, convenient for storage and transportation, and less toxic, and there are still many reports of using this type of chloromethyl source in each research document, and the hydrochloric acid used can be ordinary liquid concentrated hydrochloric acid, or Can be hydrochloric acid gas.



Hydrochloric acid gas: For example, for the chloromethylation of acetanilide and its derivatives, in a device with a gas introduction tube, add 30 ml of dry benzene at a time.







This is an global standard which acts as a form of promise that Dms Seals Technology Co.,limited manufatures according to the finest quality standards.
DMS Seals is the vital link in the supply chain, adding value with efficient and cost-effective service and solutions for our customers and our suppliers.
To offer abundant options of product is an important factor to a company, such as seal manufacturersrubber o rings manufacturers to afford high-quality products for customers.
The success of seal manufacturers of campaigns largely rides on how you market your company to the crowd.

Custom message
Chat Online 编辑模式下无法使用
Leave Your Message inputting...