By David Gibble

Whether at home, on the job or out and about, there is inherent risk in life. Simply crossing a busy street carries risk.

Traffic signals moderate congestion and our traffic laws mitigate risk for drivers, passengers and pedestrians. Even more important, the knowledge and experience of those walking or riding is the greatest possible hedge against risk.

But when we do the same tasks day after day without adverse effect, complacency can creep in. Thousands of cars pass through a busy downtown Chicago intersection every day. A similar number of people walk across that street every day. It only takes one misstep, though, to lead to catastrophe — e.g., a driver distracted or pedestrian not seeing a “don’t walk” sign.

The same analogy holds true for the industrial workplace. Take as an example the refineries, plants, facilities or terminals that handle, store, transfer and transport thousands of gallons of critical, potentially dangerous or hazardous petroleum or industrial-chemical products.

Hazardous liquids are often transferred at high temperatures and pressures. The combination raises the safety stakes for owner/operators. For example, if just one time a distracted employee, who has participated in a loading or unloading operation hundreds of times, doesn’t recognize a line is pressurized and opens it, bad things can happen.

Employees handle products safely based on good training and oftentimes decades of experience. Equipment suppliers take great pains and spend many hours and research dollars to design, engineer and develop equipment, including loading systems, hoses and couplers, for safe operations.

But all it takes is that one time…

In this regard, a recently introduced disconnect coupling is impossible to disengage — whether intentionally or by accident — when used in fluid transfers that are under high-temperature or high-pressure.

Back story

Connecting with a “twist”

Its developers say the patented Twister Locking Quick Disconnect (LQC) from OPW Engineered Systems represents the next generation of quick couplings for use in handling critical or hazardous fluids in extreme pressure or temperature conditions. It is used in place of conventional cam-and-groove and in conjunction with transfer systems that use either hoses or loading arms.

Innovation is found in the Twister design, not only in how it connects, but also how it stays connected. A fail-safe connection is achieved through four simple actions:

  • Align the hose or loading arm with the Twister LQC.
  • A one-quarter turn of the Twister engages it with the hose/loading arm.
  • The pressure or vacuum within the hose/loading arm energizes the seal.
  • The pressure locks the Twister to the hose/loading arm and prevents uncoupling if the pressure is 5 psi or higher.

The Twister LQC can only be uncoupled when all line pressure is removed. Simply rotate the Twister one-quarter turn until the nipple disengages from the adaptor’s hook-shaped design. Disengagement is also achieved without the need of special tools or equipment, which results in time- and cost-savings benefits for the operator.

The Twister LQC is available in a variety of construction materials, including stainless-steel, cold-temperature carbon steel and aluminum that enable its use in numerous severe-duty applications. It is available in six sizes — from 3/4” to 6”— all rated for use at pressure ratings equivalent to ANSI 150/300.

A petroleum refinery or chemical-processing facility is a beehive of activity. Trucks constantly arrive for delivery loads. Dozens of railcars filled with raw product arrive for unloading. Newly refined products are transferred to storage tanks. Crisscrossing the landscape is a piping network for product transfers and deliveries. loading-arm systems or hoses facilitate transfers.

Industry, over the years, when handling critical or hazardous fluids, has learned the details of safety and today’s equipment addresses these needs. Most commonly, a quick or dry disconnect coupling is what joins the hose or loading arm to the delivery or storage vessel. Quick and dry-disconnect technology delivers product containment and safety at thousands of installations.

Still, there is always room for improvement.

In fact, the situation is much like that with gasoline fueling nozzles, where small tweaks to basic designs that have remained unchanged over decades now incorporate features such as breakaway valves or automatic-shutoff devices.

While knowing the vast majority of hazardous-product handling or transfer operations are performed flawlessly, one brand, Hiltap Fittings, part of OPW, a Dover company, developed a disconnect coupling which, as previously mentioned, is impossible to disengage when transferring liquids under high temperature and pressure.

Hiltap was acquired in early 2009 by Lebanon, Ohio-based OPW Engineered Systems.

A quick walk-through

The “Locking Quick Connect,” or LQC, technology (see sidebar) is similar to that of a car radiator. When the LQC is attached to a loading arm or hose the locking mechanism cannot be disengaged until line pressure is below 5 pounds per square inch (psi), much like a radiator cap cannot be removed when a vehicle cooling system is under pressure.

LQC technology is appropriate for use in applications that include tank-truck and railcar loading and unloading, maritime vessel loading and unloading, terminal-storage connections and in-plant processing. LQCs are also versatile enough to handle any number of fluids, including oil, LPG, acids, lubricants, ammonia, paints, oilfield fracking chemicals, metal alkyls and in-steam processes.

LQC benefits also extend well beyond furnishing the highest safety levels for site personnel and the environment. For instance, it prevents high-value fluids from leaking. Volatile organic compounds (VOCs) are not allowed to enter the atmosphere. Accident or incident reduction helps lower insurance premiums and administrative costs. And easy and quick connection reduce downtime.

Final words

Only the insane cross the street hoping to get hit by a car or arrive at work knowing a release of hazardous materials will occur. Still, accidents will happen. In the realm of dangerous-liquid handling, which has benefited from the accumulation of technical improvements, the chances of an accident occurring are again lessened with the availability of Locking Quick Connect technology. Operators with loading systems and hoses that incorporate a Hiltap LQC coupler in their fluid-transfer applications are using the safest, most reliable coupling technology available to the market today.

David Gibble is Product Manager, Chemical & Industrial Business Unit for OPW Engineered Systems, part of Dover Corporation’s OPW division. He can be reached at (800) 547-9393 or David.Gibble@opwglobal.com.

OPW is a leader in integrated fluid-handling, management, monitoring and control solutions for the safe and efficient handling of critical petroleum-derived fluids from the refinery to the commercial and retail points of consumption

OPW also manufactures automated vehicle wash systems. OPW has 1,650+ employees with manufacturing operations in North and South America, Europe and Asia and sales offices around the world. OPW is an operating company within the Fluids segment of Dover Corporation (NYSE: DOV).