News and Information

　　There are three commonly used polishing methods for sanitary manholes.

　　 Hygienic manhole What polishing methods are there? Let’s take a look together.

　　1. Magnetic Abrasive Polishing of Sanitary Manholes: Magnetic abrasive polishing employs magnetic abrasives that, under the influence of a magnetic field, form an abrasive brush to grind the workpiece. This method offers high machining efficiency, excellent surface quality, easy control of processing conditions, and favorable working conditions. With the selection of appropriate abrasives, the surface roughness can reach Ra 0.1 μm.

　　2. Fluid‑polished sanitary manholes: Fluid polishing achieves surface finishing by utilizing a high‑velocity fluid carrying abrasive particles. Common methods include abrasive jet machining, liquid jet machining, and hydrodynamic grinding. Hydrodynamic grinding is driven hydraulically, causing a liquid medium loaded with abrasive particles to flow at high speed back and forth across the workpiece surface. This medium consists primarily of special compounds—typically polymeric materials—that exhibit excellent fluidity under low pressure and are mixed with the abrasive. The abrasive may be prepared from silicon carbide powder.

　　3. Ultrasonic polishing of sanitary manholes: The workpiece is immersed in an abrasive slurry and placed within an ultrasonic field, where the ultrasonic vibrations induce abrasive‑induced grinding and polishing on the workpiece surface. Ultrasonic processing exerts minimal macroscopic forces, thus avoiding deformation of the workpiece; however, it poses significant challenges in tooling design and installation. Ultrasonic treatment can be combined with chemical or electrochemical methods. By leveraging ultrasonic vibration to agitate the electrolyte solution, dissolved products on the workpiece surface are separated from nearby corrosion products or the electrolyte itself. Moreover, the cavitation effect of ultrasound in liquids can suppress the corrosion process, thereby promoting surface brightening.

　 　Hygienic manhole Used in the biopharmaceutical, dairy, beer, and beverage industries. We provide equipment, installation, commissioning, and technical training for complete fluid‑processing systems, including LVPs, liquid dispensing and dosing systems, purified water systems, filling systems, and traditional Chinese medicine extraction and concentration processes. Our hygienic manways are manufactured from imported SUS304 and 316L stainless steel, with both interior and exterior surfaces finished using high‑grade polishing equipment to meet stringent surface‑finish requirements. They satisfy the specialized media‑handling needs of the food, biopharmaceutical, and related sectors, while their smooth, seamless, self‑draining fluid pathways are ideally suited to steam‑in‑place cleaning.

　　Working principle of sanitary manholes: When the pressure below the valve stem exceeds the combined pressure above the stem and the spring force, the check valve opens. Once the valve stem is fully open and the downward pressure is balanced, the valve closes. Any further reverse pressure acting on the valve stem will cause it to close. Sanitary manholes come in two designs: one uses a clamp‑on connection, which is economical and widely employed in the food industry; the other features a thickened valve body and a two‑piece construction, offering convenient installation and removal.