Bottom Loading Arm Design

Bottom loading arms are employed to facilitate the loading and unloading of tankers from their side sections. These loading arms are typically affixed to a floor and establish a connection between the vehicle and the loading system via a special connection.

Equipment layout consideration

• Space requirement for Loading Arm Envelop – You can start by drawing the envelope of the loading arm. By doing this, we can determine when the truck needs to stop to ensure the arms can connect to the truck wagon connection. It is a bit tricky when you need to do dual-loading at the same time, so make sure the envelope is able to reach the truck nozzles.

• Space requirement for the Loading street/lane width- Make sure the size of the loading street /lane is enough for the truck to maneuver. Keep in mind,

Width = truck width (~2500mm) + clearance (arm connection with decoupler + 500mm) + left side clearance (400mm)

• Space requirement for the dosing and equipment – Defining the island’s space becomes a constraint especially if there will be flow measurement and chemical dosing of additives, as this will take up space. This will also be a driving force for you’re layout if you already have constraints in the beginning, then consider making a 2nd floor for your additive skid (dosing + instrument).

• Truck connection – the product connection is equipped with dry-break coupling to minimize leakage. The standard coupler is an API coupler which is in accordance with API RP 1004. The truck side is male and the Arm side is female. Double-check the Truckwagon operator or client for the correct connection specification. The truck connection can be on the right, left, or backside.

• Type of bottom-loading arms – choosing the right loading arm depends on the need and space availability.

• The drip tray should be able to handle the volume of product that is dripping off from the hoses. You can install a drain vessel next to it to minimize handling of the drained product. The drain vessel can be pumped out by a vacuum truck.

Piping layout consideration

• The detonation/Flame arrestor of the vapor line should be located at floor level for easy maintenance of the fire arrestor element. A horizontal position is preferable to a vertical installation as you can easily lift the fire element.

• The piping to the loading arms and loading arm should be drainable. The seal in the loading arm is often replaced. The draining facility should be able to absorb the drained volume.

• The flowmeter, controls, and chemical/additive dosing often come as a skid. So this must also be considered in your piping design whether you put it downstairs or move it up to the 2nd floor.

• Utility stations should have a minimum comprise of Nitrogen, Plant Air and cleaning water.

Some random lucky egg!

References:

1. https://www.ewfm.co.uk
2. https://wlt.nl
3. https://kanon.nl
4. https://www.omcavourresi.com
5. https://standards.globalspec.com/std/1419792/API 20RP 201004