flexible hose

The loading arm of the flexible hose on automotive tankers comes in two types: manual operation and pneumatic drive. Based on the oil filling method, they are divided into top-loading and bottom-loading types. At present, in our country, the dip pipes on motorized tank trucks are of the overhead type, except for those used on tank trucks carrying liquefied petroleum gas, liquid ammonia, etc. The overhead type is further divided into open splash type and closed submersed type. In principle, it is safer to load flammable and explosive materials under liquid level; splash loading, which tends to generate more static electricity, is only suitable for heavy and viscous oils and similar materials ； From an environmental protection perspective, volatile, toxic, harmful, and irritating substances should all be loaded in sealed containers. Regarding the choice between pneumatic and manual flexible hoses: the advantage of pneumatic flexible hoses is automated operation, which makes them easier to use than manual ones. The disadvantages are high cost, a higher failure rate, and more complicated maintenance and repair compared to manual dip pipes. Therefore, the choice between pneumatic and manual operation should be made based on factors such as the availability of personnel and the level of investment. Principles for selecting flexible hoses: 1. For corrosive fluid media, it is necessary to avoid splashing and ensure personal safety; it is advisable to use sealed loading methods or vertical hoses inserted into the bottom of the tank vehicle for loading ； 2. It is a liquid medium prone to static electricity accumulation and volatility; when loading, a vertical tube with an inserted, reflux-equipped sealed expansion tube should be used ； 3. For low-volatility liquid media prone to static electricity accumulation, plug-in long drop tubes should be used during loading; drop tubes with diverter caps or open telescopic tubes can be employed ； 4. For low-volatility liquid media, when the gases emitted during loading pose a pollution risk to the environment or a hazard to human health, loading should be carried out using an outlet design with a return air pipe, or a closed short vertical pipe or long vertical pipe ； 5. The loading and unloading of flammable liquid media of Class A and Class B shall be carried out in a closed manner; the dip pipes shall have a return gas pipe structure, and nitrogen sealing or balance pipes shall be used to maintain gas phase equilibrium, with the gas phase being returned to the tank farm equipment or production units ； 6. When loading and unloading flammable and volatile liquid media, the liquid loading/unloading arm should use a vertical pipe interface type with an outlet featuring a return air duct for sealing ； 7. For non-hazardous liquid media, open insertion or short vertical pipe methods can be used for loading ； 8. For Class A B and Class B A liquid media, bottom-loading with a sealed top cap connected to an air return pipeline should be used; the end of the vertical pipe shall be equipped with a diverter, and the vertical pipe must be lowered to the bottom of the tank before filling ； 9. For Class B and Class A liquid media, loading should be carried out underwater, and the end of the vertical pipe should be equipped with a diversion nozzle ； 10. Class B liquid media can be loaded using insert-type short vertical pipes ； 11. At a temperature of 20°C, for liquid media with a vapor pressure greater than 5 kPa(A), since the volatile gases have certain value for recovery, top-sealed container systems should be used for loading ； 12. When the ambient temperature is below the freezing point of the liquid medium, the liquid loading/unloading arm should be equipped with heating measures ； 13. When low-temperature fluidity of the liquid medium is required, jacketed heating or electric heating can be employed ； 14. When the outer wall of the heat tracing tube cannot come into direct contact with the process tube, insulation treatment should be applied

The lower-loading method is safer; the upper-loading method tends to generate more static electricity

It can be chosen according to the medium and customer requirements.

Currently, most use lower-mounted dip pipes

This post was last edited by sdwfsgyykai on 2018-6-10 08:06. If the loading/unloading port of the tank truck is located on the top of the tank, an overhead loading arm should be used； If the loading/unloading port of the tank truck is on the side, a lower loading arm should be used. Lianyungang Aide Petrochemical specializes in flexible hose production