The petrochemical industry relies heavily on pump shaft seals, which are generally categorized into contact and non-contact types. Contact seals include packing seals and mechanical seals, while non-contact seals encompass labyrinth seals, spiral seals, and vane seals. Mechanical seals are widely used in chemical pumps within the industry, accounting for approximately 80–90% of applications. They are an effective solution to issues such as leakage, wear, and inefficiency, contributing to better environmental protection, improved operational efficiency, and reduced production costs. As a result, they have become essential in modern industrial processes.
Research on seal performance has shown that in high-demand environments, such as the ZW600-80-type forced circulation pump manufactured by Guangzhou Haotian Chemical Company, mechanical seals play a critical role. This pump handles a slurry containing 8–10% (wt) salt crystals, with temperatures reaching up to 120°C and a flow rate of 2650 m³/h. The seal system includes a shaft sleeve, front and back machine covers, a seal ring, and a water seal cover. Two sets of mechanical seals are installed in tandem, with the first being a balanced external static compensation seal and the second a double-end fork-type seal. These configurations help ensure reliable sealing under harsh conditions.
Another example is the Roots pump used by Kaiping Guangdong Polyester Enterprise Group. It transports slurry with a density of 1350 kg/m³ at an outlet pressure of 600 kPa and a motor speed of 1500 rpm. The pump uses a mechanical seal for the slurry, with EG fluid used for flushing and a skeleton oil seal to prevent leakage. Improvements include replacing O-rings with fluorine rubber versions and using PTFE-based oil seals to prevent pulp from entering the sealing surfaces.
Mitsubishi Heavy Industries in Japan employs a three-seal system in its 93A reactor cooling pump (RCP). The primary seal is a film-riding end seal designed to control leakage, reducing coolant pressure from 15 MPa to 0.3 MPa. This non-contact system ensures minimal deviation over long periods, typically around one year, making it ideal for high-performance applications.
In the U.S., Joseph L. Foszcz highlighted the versatility of mechanical seals, noting their ability to handle fluids under extreme conditions—pressures up to 13.8 MPa, speeds up to 50,000 rpm, and temperatures ranging from -254°C to 649°C. He described a typical mechanical seal assembly, including the seal face, stationary ring, and O-rings, emphasizing their growing importance in industries where leakage is unacceptable.
Several patents also illustrate innovations in sealing technology. For instance, a utility model patent from Guangzhou Pump Factory (ZL99236406) describes a combined leak-free pump featuring two sets of mechanical seals arranged in parallel. The outer seal is a single-end balanced static compensator, while the inner seal is a double-end mechanical seal, ensuring separation between the transmission medium and the environment.
Nippon Pillar Packing Co. in Japan has developed non-contact shaft seals that use dynamic pressure generated by grooves on the rotating surface to create a fluid film. This design enhances sealing performance in high-pressure environments. Another Japanese patent by Mitsubishi Heavy Industries introduces a high-pressure shaft seal with grooves that guide fluid along the rotation axis, improving reliability in demanding applications.
Additionally, Nippon Pillar Packing Co.'s JP2003185030 patent features a dual mechanical seal system suitable for high-pressure equipment. The design allows for axial movement of components, reducing the overall size and weight of the seal assembly while maintaining effectiveness. These innovations continue to drive the evolution of sealing technology in the petrochemical and industrial sectors.
Galvalume Steel Coil
Galvalume steel is also called Aluminum-Zinc Alloy Coated Steel, Zincalume steel, aluminized zinc steel (aluzinc steel), SGLC. The galvalume metal is composed of 55% aluminium, 43.4% zinc and 1.6% silicon solidified at a high temperature of 600 ° C. Its whole structure consists of aluminium-iron-silicon-zinc, forming a dense quaternary crystal of an alloy.From the point of view of the degree of coating, the Galvanized Steel Coil is mainly the zinc plated on the coating, while the coating of the galvalume steel coil not only has zinc, but also has an extra part of aluminum.Galvalume steel sheet (coil) has better atmospheric corrosion resistance.
Galvalume Steel Sheet has excellent characteristics: strong corrosion resistance, 3 times that of pure Galvanized Steel Sheet; the surface has beautiful spangles, which can be used as building exterior panels.
The corrosion resistance of "Galvalume Steel Coil" is mainly because of aluminum, the protective function of aluminum. When the zinc is worn away, the aluminum forms a dense layer of aluminum oxide, preventing corrosion-resistant substances from further corroding the interior.
Aluzinc Steel Coil,Aluminum-Zinc Steel Coil,Zincalume Steel Coil,Aluminized Zinc Steel Coil
Shandong Guanzhou Iron and Steel Group Co., Ltd. , https://www.guanzhousteel.com