TRUCK & RAILCAR LOADING ARMS
What Is a Loading Arm?
A loading arm is comprised of rigid piping connected by rotating swivel joints that allow the pipe to move left or right and up or down. Loading arms are typically balanced by spring cylinders, which are springs housed inside of a pipe section or canister, to help support the weight of the arm and assist an operator in moving the arm from the stored to working positions and less commonly supported by counterweights. Loading arms can also be outfitted with pneumatic or hydraulic cylinders used to lift and move larger, longer, and heavier loading arms where a spring cylinder is less practical. Loading arms are used to transfer a variety of fluids and gases to or from tank trucks and railcars. Loading arms can be made from a variety of materials like carbon steel, stainless steel, specialty alloys like Alloy 20 & Hastelloy, can be painted and include sensors and valves. Loading arms are used in industries like the Oil & Gas, Petrochemical, Food, Pharmaceutical, Pulp & Paper and Mining markets to name a few.
What is a Top Loading Arm?
A top loading arm is used to load or unload through the top of a truck or railcars open manhole or be connected to the fixed pipe connections or valves on top of the truck or car where the manhole is not opened to load or unload. Top loading and unloading arms can be “fixed reach” where the arm is designed to be positioned in a predictable spot with minimal need for the arm to reach varying locations on top of the car or truck. This requires the truck or railcar to be positioned accurately at the designated load or unload rack. Arms can also be designed as “variable reach” where the arm can reach variable points on top of the car or truck providing the most flexibility and can compensate for trucks and railcars that may not be accurately positioned at the load or unload racks or for loading or unloading rail cars, that depending on which direction the car it turned on the rail, can have its manhole or fixed connections pointed in the opposite direction each time a car is spotted at the load rack.
Top loading arms can be provided as “unsupported boom arms” in that the overall reach of the arm or added weight, such as valves on the end of the arm, does not require any additional support steel to support the arm beyond its standard inlet flanged connection that mates up to the sites process piping.
Top loading arms can also be provided as “supported boom arms” in that the overall reach of the arm and or added weight, such as valves on the end of the arm, does require additional support steel to support the arm. The “supported boom arm” includes additional support steel work that mounts to the structure of a loading rack with pillow blocks, allowing the supported boom section to turn left & right with the main arm pipe work.
Supported Boom Ammonia Railcar Top Loading Arm
What is a Bottom Loading Arm?
A bottom loading arm is used to load or unload products from the bottom or side of a truck or railcar. Bottom loading and unloading arms can also be “fixed reach” where the arm is designed to be positioned in a predictable spot with minimal need for the arm to reach varying locations on the bottom or side of the car or trucks connections used for loading or unloading. This requires the truck or railcar to be positioned accurately at the designated load or unload spot. Arms can also be designed as “variable reach” where the arm can reach variable points on the bottom or side of the car or truck providing the most flexibility and can compensate for trucks and railcars that may not be accurately positioned at the load or unload spots or for connecting the arm to multiple connection points such as API tank trucks with multiple side connections for compartment loading various grades of gasoline and diesel fuels.
Bottom loading arms can also be provided as “unsupported boom arms” in that the overall reach of the arm or added weight, such as valves on the end of the arm, does not require any additional support steel to support the arm beyond its standard inlet flanged connection that mates up to sites process piping.
Bottom loading arms can also be provided as “supported boom arms” in that the overall reach of the arm and or added weight, such as valves on the end of the arm, does require additional support steel to support the arm. The “supported boom arm” includes additional support steel work that mounts to support structure at the load spot with pillow blocks, allowing the supported boom section to turn left & right with the main arm pipe work.
Jet A Truck Bottom Loading Arm
Loading and Unloading Arm Options & Accessories
Loading and unloading arms are used in a variety of applications from moving anything from gasoline to chocolate to acids and cryogenic products like LNG. Arms can be outfitted with dry break couplers to minimize spillage during connects and disconnects to the cars and trucks, break away couplings used to prevent damage to the arm and plant piping in the event of a drive off or pull away where the arm is still connected to the truck or car when it moves away, park position sensors, vapor recovery cones and plates, loading valves and can be Teflon lined for moving corrosive products.
Arms can also be steam jacketed or electric traced and insulated for applications that require heating of the product and process piping such as that found where products like asphalt or molten sulfur and loaded and unloaded. Arms can be outfitted with high level detection probes, leak detection monitoring and full remote automation for moving products where there is a high level of concern for exposure or inhalation hazards by eliminating the need to have any operators near the loading and unloading point during product transfer.
Electric Traced:Insulated Bottom Truck Loading Arm
A Customer Needed to Load Trucks with Renewable Diesel, Naphtha & Jet Fuel & Unload Off-Spec Product at a Single Loading Spot
A customer asked S&S Technical to provide a truck loading station with loading meter skids to load trucks with three products and unload off-spec material from the same spot. A package with canopy, metering skid for three products and offloading pump skid was provided. Bottom loading arms with API couplers were provided to allow connection to the trucks. The arms are designed to “crossover” each other allowing all three arms to be connected at the same time to the multiple connections on the side of the truck without interfering with each other. A bottom unloading arm was also provided for unloading the off-spec material. The modular approach allowed for an easy installation at the site and provided the end user the flexibility they required for loading multiple products at the same time.
