Introduction of Metal Hose for Food, Beverage and Medicine
First, Metal hoses are generally divided into four categories: screw type, flange type, quick connect type and union type according to the structure of the joint:
1. Threaded metal hose: The joints of metal hoses with a diameter of less than 50 mm are mainly threaded when they are subjected to high working pressure. The outer taper surface is tightly matched to achieve sealing. The thread form is divided into NPT thread, PT thread, G thread, R thread and national standard thread.
2. Flanged metal hose: the joint of the metal hose with a diameter of more than 25 mm is mainly flanged under the condition of withstanding general working pressure. It is sealed in the form of a tongue and groove. The loose flange that can rotate in the radial direction or slide in the axial direction connects the two bodies under the action of the tension of the tightening bolt. The structure has good sealing performance, but the processing is difficult, and the sealing surface is easy to be damaged. In special occasions requiring quick release, the hole through which the fastening bolt passes can be cut to make a quick release flange.
3. Quick-connect metal hoses: The joints of various metal hoses with a diameter of less than 150 mm are generally used under the conditions of quick loading and unloading. It is commonly sealed with “O” seals made of fluoroplastic or special rubber. When the handle is moved at a certain angle, the claw finger equivalent to a multi-thread is locked; the tighter the “O” seal is pressed, the better the sealing performance. Within a few seconds, without using any special tools, you can connect or disconnect a set of connectors.
4. Union metal hose: metal hose connector with a diameter of less than 100 mm, which is convenient for thread connection.
Second, the biggest difference between metal hoses for food, beverage and medicine and general vacuum or industrial metal hoses is that the welding process is different: general vacuum or industrial metal hoses are welded by a flat mouth, but there is an interlayer in the rear bellows, which is easy to precipitate impurities; The metal hose for food, beverage and medical uses single wave welding, no interlayer will not precipitate impurities, and the welding between the flanges is also single-sided welding and double-sided molding to ensure that there is no gap in the inner wall. It has the characteristics of high tensile resistance, damage resistance, pressure resistance, impact resistance and corrosion resistance, and has excellent electromagnetic shielding function. Waterproof, oil-proof, corrosion-proof, good sealing
