Maintenance tips and advice to ensure smooth operation during loading Operations

Category: terminal, depot, API, bottom loading, coupler

Maintenance tips and advice to ensure smooth operation during loading Operations

From the extreme desert heat of Kuwait to the icy cold conditions in Poland, walk into any fuel loading terminal and chances are you will see an operator effortlessly using a LYNX API Dry Break coupler. It has been many decades that Liquip’s Australian designed and built, gas strut assisted loading arms and API couplers have been setting the industry standard.

Liquip has been designing, manufacturing, assembling and testing equipment for the petroleum fluid handling industry for over 50 years. An innovative mindset focused on supplying customers with technical, yet user-friendly solutions has led to Liquip becoming synonymous with high quality products. All products that Liquip manufacture are designed and tested at its Sydney based facility.

In recent times, the biggest standouts in Liquip’s terminal portfolio include the world-renowned LYNX API coupler and the Velvet Touch LBM bottom loading arm. The LYNX coupler and LBM loading arm are known as industry leaders, and whilst other products perform similar functions many customers struggle to match the performance they experience with Liquip. These products provide the critical connection between the tanker and terminal and it is not unusual for API couplers to experience in excess of 50 connections in a single day. This translates to a significant amount of use and potential wear each year.

To reduce downtime and ensure continual smooth operations at each terminal it is vital to implement and follow a regimented maintenance program. By looking out for and addressing the following areas within their existing maintenance schedules, terminals can ensure their equipment is cared for and will continue to provide the utmost safety, reliability and performance:

Seal selection

As the temperature fluctuates in warm or cold climates and dependent on which products and additives flow through the loading arm, it is crucial to use the right product seals for the job. Using incorrect seals may cause the coupler and loading arm seals to become compromised, leading to product leaks. There is a wide variety of product seals available on the market ranging from seals designed to handle typical loading of fuels to those designed to handle ultra-low temperatures and even some harsh chemicals. To determine which seals are best suited to your applications it is suggested to contact your API Coupler manufacturer.

Seal wear

A coupler performs a high number of connections each day and this will cause seals to wear over time. Worn seals may cause minor leaks during loading or after the coupler has been disconnected from the truck API adaptor. This is usually an indication that the product (nose) seal or one of the other seals such as the poppet adaptor O-ring or bush and O-ring assembly are due for replacement. Terminal operators should inspect couplers on a regular basis and changeout any seals at the first sign of wear. To assist with seal changeouts Liquip, OPW and other manufacturers provide detailed changeout procedures.

Safety interlocks

API couplers are fitted with safety interlocks whereby the coupler cannot be opened until it is fully latched on to an API truck adaptor and it cannot be disconnected until the API coupler has been closed. During maintenance always check the latching function of your coupler to continue trouble-free operation.

Dirt build up on latches 

API couplers come into contact with a number of different vehicles each day and during this process dirt and other debris can build up on the API coupler latches. If too much dirt builds up on the latches, it may create a flawed seal and might prevent the coupler from latching correctly to the truck adaptor. Operators should regularly inspect and remove dirt and debris from coupler latches. 

Latch wear

As a result of the large number of collisions API couplers experience with truck adaptors, latches may wear over time. It is important for operators to check that all latches operate correctly when conducting routine maintenance. To assist operators in determining latch wear, companies such as Liquip have developed gauges that allow operators to quickly and effectively measure the latching capability of API couplers.  

Loading arms adjustment

Over time the balance mechanism of all loading arms whether compression, torsion spring or gas strut style, will droop and could lead to the loading coupler sitting just outside of the API envelope (based on API RP 1004). This could result in a coupler position that is too low to ergonomically connect to the tanker.

If the loading coupler is no longer in its most optimum loading position, operators will need to increase or decrease upward force to adjust the loading arm. Remember, before commencing any adjustments to the arm, always make sure to suitably support the horizontal spool. When it comes to gas strut operated arms, adjustments are easily completed by turning the nut on the adjustor bracket. A successful adjustment will allow the coupler to be easily maneuvered within the API envelope.

Loading arms clashing with obstructions

The up/down stops can be used to allow the loading arm to move freely without clashing into any nearby obstructions. During maintenance it is good practice to check that the horizontal arm is parallel to ground and adjust as needed, as this will ensure the maximum vertical movement of the arm.

To simplify terminal operations many bottom loading equipment manufacturers have developed advanced technologies to address the above areas and improve bottom loading operations. Liquip’s LYNX coupler and LBM gas strut loading arms are just one example of this. These products when used together, form the ultimate bottom loading experience. Key features of these include:


  • A proven seal design allowed for increased site safety and minimal product leakage during disconnect.
  • Four, "true interlocking" tried and tested stainless steel latches ensure superior automatic latching and maximum product containment during delivery.
  • An ultra-lightweight yet durable design which eases strain on the operator without reducing safety.
  • Ridiculously quick and easy disassembly of entire coupler through a unique U-pin design for ease of maintenance.
  • Fast in-field replacement of main seals, on or off the arm.
  • Easy to operate ergonomic handle with a noticeable positive lock which is available in two handle sizes to suit customer preference - Short (150mm) or Long (200mm).
  •  Typical Coupler Working Pressure: 80 psi (5.5 bar) (550 kPa).
  • Max Surge Pressure: 493 psi (34 bar) (3,400 kPa).

LBM Gas Strut Balance Mechanism

  • Liquip’s LBM800 gas strut balance mechanism known as the ‘Velvet Touch’ offers a smooth 360° rotation in the horizontal plane allowing the LBM800 to easily move from a parked to loading position and in some applications, to service vehicles on either side of the loading bay.
  • Can be easily configured to suit different styles of loading arms including low profile loading and unloading, A-frame bottom loading and even Pantograph and long reach top loading arms.
  • A Slimline drop leg bracket provides easy and out of the way installation.
  • Enhanced strength and ease of adjustment through a heavy-duty adjustment mechanism.
  • Adjustable up/down stop that can be set with minimal effort.


The LBM800 balance mechanism and LYNX API coupler both offer a variety of seals to handle various products and temperatures ranging from -40°C to +90°C. If operating at any other temperatures contact Liquip for seals or guidance.

The millions of litres of fuel that pass through a storage terminal every year would have nowhere to go without API couplers. That means their design and reliability must be second to none if a terminal is to feature a truly efficient loading-rack operation. By incorporating the above tips into terminal maintenance regimes, loading equipment will continue to provide safe and reliable performance.  

No matter where in the world you are located you can rest easy knowing that you will have local product and technical support from your experienced Liquip or OPW distributor.

To find your nearest distributor contact Liquip today.