Proactive, Secondary Containment Vessels For Preventing Hazardous Gas Release From Cylinders And Ton-Containers Now Also Available For Preventing Release From Bulk Storage Tanks

Now Also Available for Preventing Release from Bulk Storage Tanks

The inventor of unique, proactive, secondary containment vessels for preventing hazardous releases of chlorine, anhydrous ammonia, and sulfur dioxide gases, from their cylinders or ton-containers, to plant and community environments, now also offers a similar function when the gases are stored in bulk storage tanks.

The pressure secondary containment vessels option, inroduced in 2000, and which have often been deployed to allow for cylinder and ton-container use instead of bulk storage^*, have now been joined by a pressure housing solution for bulk storage tanks.

As a result, plant managements and their consultants have gained further flexibility, in choosing whether bulk storage tanks, or their 150 lb cylinders, or their 1-ton or double one-ton containers, with or without special storage rooms, with or without scrubbers, are most efficient for their gas storage. At the same time, they can consider the best options for protecting their own plant operators and their surrounding communities against hazardous gas releases, while conserving the gas they purchased. Like the containment vessels, the new pressure housing solution can be utilized for industrial process gas use, as well as for municipal water and wastewater applications.

Plant employees have often been quoted as “the biggest fans” of the secondary containment vessels, by not only making their jobs safer, but also easier, which are benefits expected to continue with the pressure housing product for bulk storage tanks.

In addition, both offer simple design, making effective training readily accomplished, while smaller companies that utilize the hazardous gases, and typically don’t have their own emergency response teams on site, can gain their own effective and efficient safety deployment.

Whether protecting cylinders or bulk tanks, both the original product and the new product offer the opportunity to avoid the need for scrubber systems, that are typically far more costly, and often less reliable. And both can still be effectively deployed when scrubbers and/or bulk tanks are already in place.

Although a room with a scrubber may protect the environment, it may do so at the risk of the operator, and installation of secondary containment vessels for compliance typically costs a fraction of the cost of a special sealed room, with self-closing doors, plus a caustic scrubber within it.

As passive safety solutions, both secondary containment products offer useful tools during plant management’s complex considerations for their Risk Management Plans (RMP’s), while providing for fail-safe protection.

The ChlorTanker pressure housing directly replaces the existing pressure plate on the bulk tank nozzle. The angle valves and pressure relief device are installed as usual, and the pressure housing can be offered with additional components of a spare parts kit, angle valves, and failsafe valves.

It adds protection against unauthorized access to pressure relief valves and angle valves, while eliminating the need for costly “C-Kit” repair and emergency response kits, which were developed by the Chlorine Institute. If for any reason their continued use is desired, special lugs are contained in the ChlorTanker to allow for that. In any event, the kits do not serve as a proactive method for containing leaks, and instead leave open the possible need for specially-suited and trained outside hazmat teams to respond to a release event.

OSHA requires a six-member trained response team to respond to the release of any toxic gas. Two response team members, who enter the space, must be in self-contained breathing apparatus and chemical suits with harnesses. Two team members must remain outside the room with tethers to extract the first two from the room if necessary, one team member stands by for decontamination, and the team supervisor coordinates the response. Many facilities do not have a six-member team to address a release.

Rudy Caparros, COO of ChlorTainer/TGO Technologies, noted a key contribution, in the design and engineering of the ChlorTanker product, from Daniel A. Thompson, P.E., a highly-regarded and broadly-experienced independent consulting engineer, who has worked for both chemical producers and their equipment manufacturers, and also as a trainer for chemical emergency response contractors, as well as a trainer for the Chlorine Institute. In addition, he has also served as an expert witness.

His 40-year experience includes evaluating various types of hazardous gas loading and unloading facilities. Particularly useful for this assignment was his experience with rail track design and maintenance recommendations, since rail car angle valves are typically the same as those on a bulk storage tank.

He has also provided training in the safe handling and storage of hazardous materials, as well as emergency response tactics and equipment. In addition, he has provided expertise in evaluating the root cause of chemical releases, and recommendations to prevent their future re-occurrence. He will be presenting at the Chlorine Institute meeting in March.

Thompson sees applicability of the bulk storage protector to a variety of industries and needs; not just for municipal (drinking) water treatment plants (WTP’s) and wastewater treatment plants (WWTP’s), which have been the most common applications for the novel cylinder and ton-container gas secondary containment vessels, and which also often have bulk storage tanks.

“We’ve seen aluminum smelting and other metals processing facilities, where chlorine and other gases are added during processing operations, take advantage of the cylinder and ton-container protection, and they often also have bulk storage tanks for those gases,” he noted in a recent interview. “Similarly, plastics manufacturing operations are the biggest users of chlorine.”

“The new tank product we engineered is readily adaptable to which gas or gases are in use, among chlorine, anhydrous ammonia, and sulfur dioxide, while not being limited to those gases. And the greatest safety concern is when they are in bulk storage, where any leaks or unintended releases are potentially the largest quantity, by far, compared to cylinders or ton-containers.”

“Encapsulating the top of the tanks alleviates those concerns about major leaks,” he continued, “because it is pre-packaged, and can capture escape from the service equipment installed on the nozzle. The new product is directly mounted on the tank, and covers the angle valves and the pressure relief device. And with the auto-shutoff, fail-safe valves, there doesn’t need to be anybody there to activate the shutdown.”

Regarding tank sizes, he added that the product development effort targeted 20-30,000 gal. tanks, that are typical for WTP and WWTP applications, but that the product can be readily adapted for larger or smaller tanks. He originally targeted the most common nozzles size, where the outside diameter of the main tank nozzle is 18 in., and where it is typically the only exit from the tank to help minimize risk, vs. multiple nozzles.

The nozzle can be larger, but he said he hasn’t seen one smaller. The pressure plate bolts to that, and has all the connectivity for the rest of what’s going to be attached to the tank. The existing pressure plate is removed, and then the new product incorporates replacing it.

“That means the installation isn’t going to be any different than what they’re used to,” Thompson noted. “including it having to be re-certified on a frequent basis; typically, every five years. It bolts on in the same fashion as just the pressure plate alone was.”

While the WTP and WWTP applications for the cylinder vessel and ton-container product have been the most common, he noted that most of his own experience with that product was with industrial process operations. There, purification is still the objective, and he is now expanding the use into precious metals recovery (recycling) operations, while also seeking opportunities for the bulk storage product in all the industrial applications where the cylinder vessel product has been deployed.

“It doesn’t care what the chemical is, or where the chemical is going downstream,” he continued.

“For example, the use may be in plastics manufacturing, which accounts for about 40% of all chlorine use, or in something like the production of iodine. Those operations are typically very large, and have capital assets like large scrubbers to deal with the safety issue already in place.”

“But their customer operations downstream, in distribution, are typically much smaller, and those managements no longer have to consider that kind of expense, including capital investment within limited real estate available, as well as needs for additional chemical management and handling.”

“They can now just capture any release that’s going to be on top of those storage tanks. There will be little change for them in their operation, and it gives them the avenue of having the protector in place to get any capture back into process, whenever they have the time to get to it, and customizing the design is also available to assist with that.”

“The recovery of the leaked gas doesn’t need to be addressed immediately at all, because everything is captured. The device can be designed to feed into their process like they normally do. And if they already have a scrubber, they can just feed what’s captured in this new device, and not have to deal with the tremendous volume of air inside the room as a scrubber typically does.”

“They could avoid using the scrubber at all, or if they want, just use it in much more efficient fashion by just scrubbing what was captured.”

“In terms of applicable gases, we’re dealing with chlorine, anhydrous ammonia, and sulfur dioxide right now because we’ve already been there, but I’m not going to say there couldn’t be applications for all kinds of other gases. It should be very adaptable to other chemicals.”

“All three of the present leak capture designs (150 lb. cylinder vessel; 1-ton and double one ton container vessels; and now the tank product), yield the same positive results for the owner with the same basic design. On the tanks, it’s containment of the highest-potential leak points, and the highest risk, because it’s potentially the largest amount, by far.”

“With the bulk tank protector in place, they could easily go five or six years, until their next requalification, and not have to touch anything on it. Everything that’s sealed up stays the same until the next time you want to qualify the tank. Relief vales and four service valves are now sealed inside, along with the bolted connections, and a valve packing gland potential leak point ---all those could be physically be seen on a tank, but now they would be encapsulated.”

“If they are taking in chemicals into the plant via bulk tank cars, they are not a small user, with rail cars having a 90-ton capacity, but they still have a bulk tank in the plant to receive product.”

“You should never have to use emergency capping kits, but we have lugs installed, so if for some reason you still wanted them installed you could put them on. The C-kit was designed specifically for rail tank cars and cargo tankers, and also storage tanks in a lot of cases.”

“The ChlorTanker should be especially popular with the workers in the plants, just as the ChlorTainer cylinder and ton-container vessels have been. That’s because they make their jobs easier; they are easily trained in their use; and they readily see the enhanced safety benefit.”

The 2500-lb. carbon steel ChlorTanker, with design pressure @250 psig @300 F, is easily installed, simply bolting down to any existing manway. Installations are available from one of 3 specially-trained separate companies, who also are qualified to perform requalification pressure tests.

For further information, contact ChlorTainer/TGO Technologies Inc., www.ChlorTainer.com, (800) 543-6603, sales@ChlorTainer.com.

^*These cylinders and ton containers can now be installed and operated in and from a total containment vessel to comply with the latest revision of the California Fire Code, Title 24, Part 9, Article 80. This code requires that every chlorination system using chlorine supply cylinders must have a treatment system for mitigating accidental releases of chlorine gas or liquid chlorine