This guide is applicable to various high-pressure hoses made mainly of polyvinyl chloride (PVC) for pipeline systems used to transport liquids, gases, and other media.
2、 Pressure characteristics
1. Rated working pressure: The rated working pressure of PVC high-pressure hoses is generally between 1.0MPa and 6.0MPa, depending on the specifications and models of the hoses. For example, a common 1/2-inch PVC high-pressure hose has a rated working pressure of about 3.0MPa, while a 3/4-inch hose has a rated working pressure of about 2MPa. It is essential to ensure that the system pressure does not exceed the rated working pressure of the hose during use to prevent hose rupture and potential safety accidents.
2. Pressure testing: Newly installed hose systems should undergo pressure testing before being put into use. The test pressure should be 1.5 times the rated working pressure, and the holding time should not be less than 15 minutes. Only when there is no leakage or rupture can it be put into normal use.
3、 Temperature resistance performance
1. Conventional temperature resistance range: The normal operating temperature range for PVC high-pressure hoses is -15 ° C to 70 ° C. Within this temperature range, the hose can maintain good flexibility and mechanical properties. The higher the temperature, the lower the pressure resistance and accelerate aging.
2. Precautions for low temperature: When the ambient temperature is below -15 ° C, the hose will gradually become hard and brittle, and its impact resistance will significantly decrease. At this time, it is necessary to avoid bending or squeezing the hose to prevent it from breaking. If used in cold regions, insulation measures can be considered for the hoses or cold resistant PVC high-pressure hoses can be selected, with a minimum operating temperature of -40 ° C.
3. High temperature precautions: When the temperature exceeds 60 ° C, PVC material will accelerate aging, and the strength and pressure resistance of the hose will decrease. If used in high temperature environments, the service life of the hose should be shortened, and the condition of the hose should be checked regularly. If necessary, please replace it in a timely manner. The recommended replacement cycle is 6 months.
4、 Aging resistance performance
1. Aging factors: PVC high-pressure hoses may experience aging due to natural factors such as ultraviolet radiation, oxygen, temperature, and humidity during use. Among them, ultraviolet radiation and oxygen are the main factors causing aging. Long term exposure to sunlight or high concentration oxygen environment can cause aging symptoms such as discoloration, cracking, hardening, and brittleness on the surface of the hose.
2. Anti aging measures: In order to improve the anti-aging performance of the hose, additives such as anti ultraviolet agent and antioxidant can be added in the production process of the hose. When used outdoors or in harsh environments, try to lay the hose in a dark and cool place, or use sleeves, cable trays, and other methods to protect the hose and reduce direct contact between the hose and the external environment.
5、 Corrosion resistance performance
1. General corrosion resistance characteristics: PVC has good corrosion resistance to most inorganic acids, alkalis, salts, and is suitable for transporting media such as water, seawater, dilute acids, dilute alkalis, and oil products. For example, in agricultural irrigation systems, PVC high-pressure hoses can be used to transport aqueous solutions containing certain fertilizer components; PVC high-pressure hoses can also be used in the transportation of certain low concentration acidic and alkaline materials in chemical production.
2. Special media precautions: PVC is not resistant to strong oxidants (such as concentrated sulfuric acid, concentrated nitric acid, etc.), aromatic hydrocarbon solvents (such as benzene, toluene, etc.), and ketone solvents (such as acetone, butanone, etc.). When in contact with these special media, it is strictly prohibited to use PVC high-pressure hoses to avoid rapid corrosion and damage to the hoses, which may cause medium leakage and lead to safety accidents and environmental pollution.
6、 Usage and maintenance
1. Installation requirements: During installation, twisting and excessive bending of the hose should be avoided, and the minimum bending radius should generally not be less than 10 times the outer diameter of the hose. The connection between the hose and the joint should be firm and reliable, and the connection should be well sealed to prevent leakage.
2. Regular inspection: Regularly inspect the appearance of hoses in use to see if there are any abnormal phenomena such as wear, scratches, bulges, leaks, aging, etc. If any problems are found, they should be replaced or repaired in a timely manner. Generally, it is recommended to conduct a comprehensive inspection every six months; In harsh environments or high load usage conditions, the inspection cycle should be shortened.
3. Storage conditions: Unused hoses should be stored in a dry, ventilated, dark, away from heat sources and chemical pollution sources, avoiding long-term pressure, moisture, and direct sunlight. The storage temperature should be between -10 ° C and 35 ° C, and the relative humidity should not exceed 70%.
