Propylene loading and unloading process

Propylene loading/unloading process: 1) Connect the tank truck to the flange of the propylene unloading pump; a high-pressure hose with a woven outer layer should be used for the pipeline from the tank truck to the inlet of the propylene pump； 2) Vapor connection line between the tank truck and the propylene storage tank ； 3) Open the primary and secondary valves at the tank truck outlet, open the primary and secondary valves at the propylene storage tank inlet, open the valve connecting the tanks, and open the vapor equilibrium valve of the tank truck. 2) Rotate the propylene pump manually to check the lubricant level and ensure it is in good condition and functional. 3) Fully open the two valves at the inlet of the feed pump, press the green start button to activate the raw material pump, open the two valves at the outlet, and observe the pressure changes indicated by the pressure gauge at the outlet. Adjust the opening degree of the outlet valve so that the pressure remains stable at around 1.8 MPa. If necessary, open the outlet pressure relief valve to release pressure and allow more fluid to flow through the pump. 4) Pay attention to the liquid level changes in the tank trucks and propylene storage tanks; change tanks when the liquid level in them drops below 20%. When changing tanks, open the valves first and then close them to prevent pressure buildup in the pump. 5) When the liquid level in the propylene storage tank reaches 80%, stop the transfer pump, close the pump’s inlet and outlet valves, as well as the outlet valves, inlet valves, and balance valves of each tank. 6) When pouring into the tank, ensure that in addition to the tank being poured into, the inlet valves and balance valves of all other tanks are closed to prevent cross-contamination of materials. Propylene vapor is heavier than air, with a relative density of 1.48 compared to air. The propylene leaking from the equipment pipelines vaporizes and settles on the ground, making it difficult for it to spread. When the concentration of propylene vapor in the air reaches a certain level, it will catch fire upon contact with a source of ignition. When the concentration of propylene vapor in the air reaches within the explosive limit (2–11%), a spatial explosion will occur upon the presence of an ignition source. To prevent fires and explosions, the following points should be noted: 1) Ensure proper equipment management and operate in strict accordance with regulations to avoid the release of flammable materials. 2) The discharge of flammable substances such as propylene at the site is prohibited. 3) Maintain good ventilation at the site. 4) Install combustible gas detectors in areas where leaks are possible. 5) If a leak of propylene or other flammable materials is detected, the leak should be repaired promptly to cut off the source of these flammable substances. 6) When the concentration of flammable gases at the site is high and may reach the level capable of causing combustion and explosion, in addition to promptly eliminating the source of leakage, a dedicated person should be assigned to monitor the site to prevent any introduction of ignition sources. Cars and fire trucks must be equipped with flame arrestors, and it is prohibited for them to enter areas with high concentrations of flammable gases. Do not turn on or off electrical equipment switches that are not explosion-proof at the site, to prevent the generation of electrical sparks. When power shutdown is required, the switch should be turned off in the substation located in a safe area away from the site. 7) Implement proper anti-static measures; easy grounding should be provided at pipeline connections as well as on the tank truck itself. 8) Personnel must wear anti-static clothing; shoes with metal nails are prohibited.