Hoses unloading

Conveyor installations maybe permanent or a combination of permanent and portable. The latter kind is often mounted on a bulk-deliveiy vehicle, which permits fast unloading into the customers silo by the carrier without effort or equipment from the customer. Controls range from simple motor starters and hand-connected hoses to sophisticated, microprocessor-elec tropueumatic control systems. 

What if the liquid unloading hose partially ruptures ... 

For flammable liquids, top loading or unloading of tank cars or tank trucks by pump typically has the lowest risk of spill or release. Metallic piping is recommended for loading/unloading arms and piping. Use of hose should be minimized and, where possible, metallic hose specified. Standard loading racks should be provided that permit safe access by personnel to the rack itself and onto the tops of the cars or trucks. Fall protection is a key issue. 

A fire water main should be provided to the shore terminus area of the wharf. Hydrants and monitor nozzles should be located so that effective fire water streams can be remotely applied to any berth or loading/unloading manifold from two directions. Where the wharf is of such length that onshore monitors cannot adequately cover the berths, the fire water main should be run onto the wharf to permit the required monitor and fire hose coverage. Monitors located on marine wharves may be remotely operated from onshore and use of elevated monitors is common. The offshore segment of the main can be a dry system. In all cases, isolation valves and fire department connections should be provided at the wharf-to-shore connection (ISGOTT, 1996). 

Materials that are not recommended for nitric acid service are 304 stainless steel (DIN/EN 1.4301 = UNS S 30400) and 316 stainless steel (DIN/EN 1.4401 = UNS S 31600). All hoses for nitric acid loading and unloading should be made of poly ethylene (PE), FIFE or polypropylene (PP)97. 

Figure 2-2 Collapsed tank truck with unloading hose connected.

At this point the unloading activity appeared normal (see Figure 2-3). In less than an hour, the truck driver checked the sight glass on the truck and informed the control room that the truck was empty. The busy operator passed by and observed that the unloading hose was still vibrating, indicating to her that the tank truck was not quite empty. 

Hoses are essential within chemical plants. They are often necessary to purge vessels, to wash vessels, to load and unload trucks, rail cars, barges, and ships. Hoses help to compensate for unavailable equipment, to prepare for maintenance, to safely vent systems, and... 

Equipment for Unloading Tank Cars and Tank Trucks. The unloading of tank cars, isotankers, or trucks requires fittings and adapters to connect the unloading line to the tank car, isotanker, or tank outlet. Tank cars generally require 10 cm (4-inch) outlets, whereas 7.6 cm (3-inch) outlets are standard for tank trucks. Flexible hoses made from carbon steel, neoprene, plastic, aluminum, or stainless steel (types 302, 303, 316) are suitable. 

Tank trucks typically have 20,412-kg (45,000-lb) capacity. Generally, tank trucks are made of stainless steel but have no standard shape or construction. Heating coils can be installed when carrying oils that might solidify during shipment. Tmcks are provided with a bar marker to indicate maximum load level, are insulated, and carry 4.6 m (15 ft) of 7.5 cm (3-inch) hose and the fittings required to unload the oil to a storage tank. 

Fresh catalyst is normally delivered in hopper-bottom railroad cars. The catalyst may be withdrawn by gravity flow from the bottom of the car through a hose to a Fuller-Kinyon screw pump and transferred to the hopper by means of an air stream loss of catalyst is prevented by a cyclone on the air discharge from the hopper. Alternatively, the catalyst may be unloaded from the top of the ear by a vacuum lift. In this case, the suction line passes through a separator with bag filters, located above the storage hoppers. The catalyst collects in a chute and flows down through a rotating barrel-valve feeder into a screw conveyor which transfers the catalyst to the hopper (105). 

Solvent is unloaded either by gravity or by pump to the customer s storage tanks. For intraplant distribution, small mobile tank trucks are commonly used. There are several manufacturers of this equipment. The type chosen should be fitted with a solvent-resistant plastic hose, a level indicator, and either a hand- or motor-driven pump. A 275-gal (1040-L) domestic fuel oil tank, mounted on wheels and fitted with equiva-... 

Flexible metal hose of bronze or stainless steel should be used for connecting a tank car or tank truck to the main unloading line. This will prevent breaking or bending of stationary pipe as the springs raise the tank car or truck during unloading. (Most trucks have or can have their own hoses.) A flexible hose lined with polyvinyl alcohol resin, polyvinylidene chloride, or polytetrachloroethylene plastic is also suitable for such use. The polyvinyl alcohol, however, must be protected from moisture, which readily attacks it. 

Pipelines at loading/unloading points, whether they are points for hose connections or are solid pipelines... 

To deal with small spillages, particularly where the material spilt may make the surface dangerously slippery, a small ready-for-use stock of adsorbent should be available at tanker loading/unloading bays where the contents of a hose may be split. 

Piping in transfer lines should be free of loops and pockets. Unloading connections may be flexible hose (typically 50-mm) lined with acid-resistant rubber, crosslinked polyethylene, or a fluorocarbon polymer. These hoses should not have quick disconnects. They should be inspected after every use. A sight glass on the transfer line will let the operator know when transfer is complete. 

Tujague [70] suggested specific improvements beyond what has been normal practice. These include providing an enclosure for the delivery vehicle, support for the unloading hose, and design of the piping supports for seismic zone four. 

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