Pressure vessels can be as mysterious as a mad scientist’s thought experiment. Externally, they appear dull and unremarkable. Yet, inside, gases are packed so tightly that any leakage or accidental discharge risks a dynamic, life threatening eruption.
However, the absence of these gases when critically needed can be equally life threatening. UK-based Coltraco Ultrasonics is in the business of monitoring such to determine that the liquefied and non-liquified gaseous contents are there and in the quantity required in an emergency.
With applications in marine and fire safety, the instrumentation and monitoring systems manufactured by Coltraco guarantee that the fixed liquefied gaseous fire extinguishing systems are ready to operate in the “ungoverned space,” which is what the company CEO Carl Hunter refers to it as.
“The ungoverned space is defined as the areas in relation to special hazards where gaseous extinguishing systems are used,” Hunter said.
In fixed systems, the liquefied gases of choice are carbon dioxide, halon, and the halon replacements such as Novec 1230 or FM 200. Halon was taken out of production after it was determined to be an ozone destroying agent but is still available for use. Non-liquefied gases such as inergen and nitrogen are also used.
Determining if these systems are adequately charged is often a study in subjunctive reasoning. Not wishing to compromise the strength of the bottle, the only monitoring device is usually a pressure gauge placed at its single opening.
Other than that, the only means of verifying the liquefied gas level is to remove the vessel or bottle from operation and weigh it.
“On a huge commercial ship there might be as many as 600 100-pound cylinders,” Hunter said. “You can imagine that it would take an incredibly long time to service that ship.”
The key to Coltraco’s method for monitoring those contents is ultrasound, he said. Ultrasound is merely sound beyond humans audible range. Dolphins and whales can communicate at sea over long ranges as sound travels more efficiently through liquids than air.
“We use sound beyond our audible range,” Hunter said. “We’re broadly measuring the difference of speed and sound through different mediums. For example, sound travels more quickly through water than it does through air.”
The ultrasonic liquid level handheld device is capable of detecting the difference in speed of sound traveling through liquefied contents as opposed to the vapor space inside the bottle.
“It then will identify the point at which the sound travels at different speeds, thereby identifying the levels with a credible accuracy,” Hunter said.
The challenge for Coltraco in designing its new innovation is the diversity of size and thickness in the cylinders used. Adding further complication is the different surface conditions of these cylinders.
“We can claim global leadership in this field because we have mastered the ability to work through everything from clean surfaces to rusted exteriors, which is common to find in older ships,” Hunter said.
The U.S. Navy adopted Coltraco’s technology based on its ability to deliver accuracy to within one-eighth of an inch despite the variety of different thickness found in cylinder walls, he said. Coltraco products are both UL (United Laboratories) listed and ABS (American Bureau of Shipping) approved.
Aside from the marine application, Coltraco devices are mosoften found in electronic data centers, Hunter said.
“America has the world’s largest number of data centers,” he said. “You might be surprised to hear that the United Kingdom has the second largest number. Helping to protect these centers is a huge application because they are designated in both countries as critical infrastructure.”
An important part of covering data centers is determining if the protected space is able to contain the discharged gas long enough to be effective.
“At the moment, the only test for that is called a door fan test,” Hunter said. “It is used to determine if the room can withstand the force of the pressure upon gas actuation.”
But as a structure ages it develops new leak sites. If those sites become large enough, the fire will not be extinguished.
Fortunately, another area of expertise for Coltraco is testing watertight and weather-tight seals on-board naval vessels. This technology has been adapted as a means to test any protected space for leakage without performing an actual discharge.
The naval bend in Coltraco’s product line is no accident. Hunter’s family has a long history of involvement in the development of SONAR, an acronym for “sound, navigation and ranging.”
“Use of ultrasound in the Navy is generally called SONAR,” Hunter said. “This year is the 101st anniversary of its first use at sea.”
The United Kingdom’s naval warfare force, the Royal Navy, employed ultrasound ranging techniques to locate German U-boats during World War I. Its original name was ASDIC (Allied Submarine Detection Investigation Committee).
“Over the next 20 to 30 years, as ASDIC developed, the Americans renamed it SONAR,” Hunter said. “And that’s the term used by the Royal Navy now.”
Hunter’s father served 27 years in the Royal Navy Submarine Service, then five years at the Admiralty Research Laboratory that supports the work of the Royal Navy.
“It was his concept that has enabled us to be the company we are today,” Hunter said. “And he spent half of his career working with the U.S. Navy and the Royal Canadian Navy.”
Work is underway to apply Coltraco’s ultrasound technology to bigger issues in industrial safety. A new device on the drawing table will be capable of measuring the contents of large-diameter storage tanks up to 150-feet in diameter, Hunter said.
“We’re not quite satisfied with it at the moment,” Hunter said. “But we’re pretty close.”