What are the material characteristics of B-type pipes
                    
                    
                        Information summary:B-type pipe "does not specifically refer to a fixed material pipeline, but rather a type of pipeline classified by structure, standard, or purpose. Its material characteristics need to be analyzed in conjunction with the corresponding materials for specific application scenarios (such as water supply and drainage, HVAC, chemical, etc.). The common B-type pipe materials include PVC-U, PE, cast iron
                    
                    
                               B-type pipe "does not specifically refer to a fixed material pipeline, but rather a type of pipeline classified by structure, standard, or purpose. Its material characteristics need to be analyzed in conjunction with the corresponding materials for specific application scenarios (such as water supply and drainage, HVAC, chemical, etc.). The common B-type pipe materials include PVC-U, PE, cast iron, stainless steel, etc. The characteristics of different materials vary significantly.
1、 Common B-type pipe materials and core characteristics
1. PVC-U (rigid polyvinyl chloride) B-type pipe
       PVC-U is a widely used plastic material in B-type pipes, mainly used in the field of civil building water supply and drainage.
       Physical characteristics: Hard texture, low density (about 1.38g/cm 3), weight only 1/5 of cast iron pipe, easy installation and handling.
       Chemical characteristics: Strong corrosion resistance, stable to common chemical media such as acid, alkali, salt, etc., without rusting or scaling.
       Mechanical properties: Moderate compressive strength, meeting the pressure requirements of indoor water supply and drainage in buildings (usually working pressure ≤ 1.0MPa), but poor impact resistance and easy brittleness at low temperatures.
       Other characteristics: Smooth inner wall, low water flow resistance, excellent hydraulic performance; Low cost, high cost-effectiveness, but poor heat resistance (operating temperature ≤ 40 ℃), not suitable for hot water pipelines.
2. PE (polyethylene) B-type pipe
       PE material B-type pipes are mostly made of high-density polyethylene (HDPE), focusing on scenarios such as municipal water supply and drainage, gas transportation, etc.
       Physical characteristics: Good flexibility, bendability, strong impact resistance, can maintain good toughness even in low temperature environments (-40 ℃), and is not easily broken.
       Chemical characteristics: resistant to chemical corrosion, high tolerance to various organic solvents and acid-base media, non-toxic, in compliance with food grade hygiene standards, and can be used for drinking water transportation.
       Mechanical properties: high compressive and tensile strength, good long-term stability, excellent aging resistance, and a service life of over 50 years.
       Other features: Good welding performance, seamless sealing can be achieved through hot melt and electric fusion connection, and excellent anti leakage effect; Smooth inner wall, not prone to scaling, suitable for large-diameter and long-distance conveying pipelines.
3. Cast iron B-type pipe (such as B-type flexible cast iron pipe)
       Cast iron B-type pipes are made of ductile iron or gray cast iron as raw materials, mainly used for building drainage and municipal sewage transportation. The core advantages are sealing and durability.
       Physical characteristics: dense material, heavy weight, sturdy structure, and superior high temperature resistance compared to plastic pipes (able to withstand temperatures above 100 ℃).
       Chemical characteristics: Strong corrosion resistance, the surface can be further improved for corrosion resistance through galvanizing, painting and other treatments, suitable for humid and corrosive environments.
       Mechanical properties: High compressive and impact strength, able to withstand large external forces and pipeline self weight, suitable for high-rise building drainage and underground burial scenarios.
       Other features: Adopting flexible interfaces (such as rubber ring sealing), with good sealing performance, it can adapt to pipeline settlement, vibration and other    deformations, reducing the risk of leakage; Long service life, up to 30-50 years, but installation requires heavy equipment and is costly.
4. Stainless steel B-type pipe
       Stainless steel B-type pipes are mostly made of materials such as 304 and 316L, and are suitable for scenarios that require high hygiene and corrosion resistance, such as the food, pharmaceutical, and chemical industries.
       Physical characteristics: The surface is smooth and clean, not prone to bacterial growth, and meets hygiene standards; Excellent high temperature resistance (304 stainless steel can withstand temperatures above 600 ℃) and low temperature resistance.
       Chemical properties: Highly corrosion-resistant, with high tolerance to harsh media such as strong acids, strong alkalis, and seawater. 316L material also has the ability to resist chloride ion corrosion.
       Mechanical properties: high strength, good toughness, strong fatigue resistance, not easily deformed after long-term use, and can withstand high working pressure.
       Other features: Long service life (up to 70 years), low maintenance cost, but expensive material price, high processing and installation process requirements.
2、 Core influencing factors of material properties
       The differences in the characteristics of different B-type pipe materials are essentially determined by their application scenario requirements, and the following dimensions need to be focused on:
       Pressure and temperature: Stainless steel and cast iron pipes are preferred for high-pressure and high-temperature scenarios; PVC-U and PE pipes can be selected for low pressure and room temperature scenarios.
       Medium characteristics: PE and stainless steel pipes are selected for transporting corrosive media; Select PE and stainless steel pipes (sanitary grade) for transporting drinking water; Cast iron and PE pipes are selected for transporting sewage.
       Installation environment: When burying underground, anti settlement and anti-corrosion measures should be considered, and PE or cast iron pipes can be selected; Indoor installation focuses on lightweight and low-cost, with PVC-U pipes available as an option.
       Service life and cost: Pursuing long-term durability, choose stainless steel and PE pipes; Choose PVC-U pipes to control initial costs.