November 2018


Keeping Up with the Times: Mechanical Grooved Couplings Still Deliver

By Austin Stevens

It is not often that looking backward provides insight into the future, but examining the evolution of the world’s first mechanical coupling can give us an indication of what lies ahead.

Next year marks the 100th anniversary of what began as the “victory joint,” a mechanical grooved coupling with a gasket seal that has played a pivotal role for nearly a century in transporting and handling crude oil, gas and refined products, and in the extraction and refining of petroleum products.

Before this device was introduced, industry relied primarily on welders to join pipe, an expensive and time-consuming method that required skilled workers, and special equipment. In addition to the risks inherent to the welding process were hazards introduced in locations where the atmosphere contained flammable gases. Further complicating this method was the difficulty encountered when trying to determine the quality of a weld. Poorly executed welding led to leaks, which result in fiscal and physical losses.

Changing the Field

The mechanical grooved coupling concept was groundbreaking. It introduced efficiency, economy and safety, and allowed pipelines to cover more distance than ever before. Oil and gas companies began adopting nontraditional pipe joining methods in the early 1920s, using the products primarily for oil production and supply lines. With the acceptance of the technology by companies like Shell Petroleum and Standard Oil, use across the industry grew. By the end of the 1930s, these products were specified as standard equipment where pipe was used for transporting and handling crude oil, gas, and refined products. 

The popularity of the mechanical coupling was a byproduct of its simple design and durability. With few parts, fast assembly and disassembly, and a strong reliable joint, the couplings were saving time and money. And while safety was not always the leading consideration for the companies that initially used the mechanical joint, the technology, in fact, reduced the number of injuries on the worksite.

Making History

Mechanical grooved couplings were part of the 1932 renovation effort on the Panama Canal. They later proved critical to the recovery effort following the London Blitz during World War II, allowing emergency workers to assemble temporary water lines to fight fires that threatened to destroy the city.

During that same time, the couplings were used in the construction of the U.S. government’s 4,600 Liberty Ships, expediting assembly of piping systems for cargo ships, landing craft and other Navy vessels. Later, they were used in Burma to build the longest petroleum pipeline ever constructed to that point, covering 3,200 miles (5,150 km).

The ensuing decades saw the grooved couplings being used in a range of applications. Oil and gas production in higher-pressure environments required more durable couplings, a need that was met with several versions of an innovative, high-pressure grooved coupling, first introduced in 1963. These couplings – used in separators, flow lines, wellheads, production manifolds, heater treaters and storage tanks – had the highest-pressure rating for couplings in the industry at the time, which allowed operators to push the boundaries into new frontiers.

Purposeful Innovation

Changing demands led to various designs, several of which have increased both performance and safety. Victaulic Installation-Ready couplings, introduced in 2005, allowed piping system construction to be carried out in a fraction of the time, leading to faster production and resulting in fewer issues once online. 

When the demand for a corrosion resistant piping material grew, new products were developed specifically for high-density polyethylene pipe (HDPE). This material is being used more frequently today in oil and gas applications, because of the advantages it provides over alternative materials such as steel, cement, PVC and other plastics. This change created opportunities to evaluate mechanical pipe joining methodologies and develop a grooved coupling solution, simplifying and expediting pipe joining by utilizing basic tools and methods not affected by weather conditions.

Advancing Technology

As industries incorporate new technologies and adapt to changing expectations, companies that provide solutions must be working to ensure they can deliver reliable results. Meeting the project schedule is critical, but that objective must be met without compromising quality and safety. New ways of executing projects must be simple and efficient and avoid introducing additional risk.

One of the ways of achieving risk reduction is by providing prefabricated, high-quality components that are ready to install when they arrive at the worksite. Installation-ready parts can be manufactured in a controlled area where construction variables can be managed. This allows the historically tedious makeup of parts to be moved off the critical path and eliminates the negative impact that time-consuming, on-site construction could have on the project schedule.

Safely achieving efficiencies is a goal that is met in part by speedy installation that can be executed without using complicated tools by workers who do not have to receive special training. Finding durable components that are easy to install can dramatically impact not only the project schedule but the complexity of maintenance activities down the road.

The best and most valuable components for the industry are those that:

  • Can be installed by general laborers
  • Are easy to install in any weather conditions
  • Help reduce construction costs by cutting down installation time
  • Arrive ready to install following extensive factory acceptance testing
  • Can be replaced easily when maintenance dictates
  • Meet regulatory requirements from agencies like NACE and API. P&GJ

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