Material selection and composite structure design of chemical conveying rubber pipes
Chemical conveying rubber pipes need to be optimized for the corrosion characteristics of strong acids, strong bases, and organic solvents. The inner rubber layer often uses hydrogenated nitrile rubber (HNBR), whose molecular chain structure can resist the penetration of polar solvents such as benzene and ketones; The reinforcement layer is formed by cross weaving polyester fibers or aramid fibers, combined with high modulus steel wire spiral winding, to form a multi-layer compressive and deformation resistant support system. For example, the pipeline transporting concentrated sulfuric acid needs to use double-layer FKM lining and add polytetrafluoroethylene (PTFE) diaphragm between the fiber layers to achieve a medium permeability of less than 0.1g/m ² · h. This type of composite structure design considers both chemical corrosion resistance and mechanical strength, meeting the mandatory requirements of ISO 2398 and other standards for burst pressure (≥ 20MPa) and pulse life (>2 million cycles).
Chemical compatibility testing and dynamic performance evaluation system
The chemical stability of rubber tubing needs to be verified through laboratory accelerated aging testing. ASTM D471 standard stipulates that the pipe should be immersed in a specific concentration of chemical medium (such as 30% hydrochloric acid, 50% sodium hydroxide) for 168 hours, with a volume expansion rate of less than 10% and a hardness change of less than 15 ° IRHD. In terms of dynamic performance, it is necessary to simulate actual working conditions for pressure temperature cycle testing: within the range of -30 ℃ to+150 ℃, apply pressure pulses at a frequency of 10Hz (peak pressure is 1.5 times the working pressure) to verify the anti crack propagation ability of the pipe body. In addition, for the scenario of transporting fluid containing particles (such as electroplating solution), it is necessary to evaluate the anti erosion performance of the inner wall wear-resistant coating (such as silicon carbide modified rubber) to ensure a service life of more than 5 years.
Multi scenario industrial applications and technological iteration direction
In the fields of chemical, pharmaceutical, and semiconductor industries, chemical conveying rubber pipes need to be adapted to differentiated scenarios. For example, in the wet process of semiconductor manufacturing, pipelines need to pass SEMI F72 certification to prevent ion precipitation from contaminating ultrapure water; The pharmaceutical industry requires compliance with FDA 21 CFR 177.2600 standards to ensure material inertness when transporting ethanol and acetone. The current technological iteration focuses on intelligence and environmental friendliness: on the one hand, integrated fiber optic sensors monitor pipe wall stress and medium leakage in real time; On the other hand, developing bio based rubber (such as epoxy vegetable oil modified EPDM) to replace traditional petroleum based materials can reduce carbon footprint. This type of innovation drives the upgrading of chemical transport pipes towards high precision and sustainability.
