Introduction
The ultimate goal is to achieve a zero cost of ownership for any installation. But is that a reasonable goal? The logical answer would be no. However, when it comes to loading facilities, a well thought out concept would allow one to come a long way towards this target.
The transfer of fluids is the backbone of companies who produce or trade these fluids or provide storage capacity. At the end of the day, it is the fluid flow that keeps the meters counting and that generates the cash flow. This article will discuss the last part of the liquid transfer line: the loading facility; the most critical part of the transfer of fluids between a storage tank and a tanker.
The Loading facility is a flexible part in the liquid transfer line as it needs to follow the horizontal and vertical movements. This flexibility requires the use of loading hoses or loading arms; this is particularly vulnerable to risks, due to emergency situations, faulty operation and wear and tear.
Loading and unloading process at the jetty
Loading and unloading of ship tankers is a challenging event which includes several risks. Considering the dynamics inherently associated with a transport vessel while connecting and transferring to and from a liquid cargo transfer system, such as a hose loader or loading arm, accidents can easily happen during any of the operational phases.
Marine loading hoses and marine loading arms are two available alternatives to transfer liquids between a storage tank and a tanker, as they offer the required flexibility. Ship to shore connections made by hoses offers better flexibility, but compared to loading arms they are prone to tear and wear; they have a limited lifetime and require relatively inconvenient operation. Hoses are often subject to periodical tests and inspections, once or twice a year, thus they inherently include a certain yearly cost of ownership. From a safety point of view, automatic emergency release provisions with ‘zero’ spillage are hardly available for hoses and neither are actuated quick couplers that make life easier for operators.
Connections made by marine loading arms achieve a fully rigid connection, still with the possibility to follow all the ship’s movements by the use of swivel joints in between the steel pipes, and so solve the disadvantages of loading hoses. They can also be executed with automatic ‘no spillage’ emergency release couplers and equipped with powered quick couplers to increase personal safety and to protect the environment. The structural design of the marine loading arms is an extremely important factor when it comes to required maintenance.
The human factor contributing to the cost of ownership is not always visible, but it has a close relation to the convenience of operation and the maintainability of the loading arms. Any difficulties in the everyday operation and in the maintenance procedures will have a decided impact on the operators.
To increase job satisfaction and job performance, the facility and the operation of loading arms and maintenance should be designed through the eyes of operators and maintenance crew and suited for one man operation. For example, flexible wires with pendants for regular loading arm control should be avoided, as they can cause accidents and are prone to getting damaged, thus causing unexpected movements of the arms.
To read the rest of this article download PDF
