Canadian Contractor Questions Rinks' Cautious Approach to ‘Very Small’ Ammonia Leak

By Michael Garry, Dec 03, 2019, 17:50 3 minute reading

The Alberni Valley Multiplex in Port Alberni, British Columbia, has reopened its two ice rinks following a more than three-week closure.

The Alberni Valley Multiplex in Port Alberni, British Columbia (B.C.), Canada, reopened its two ice rinks in recent days following a more than three-week closure caused by a “very small leak” that could have been safely resolved in under a day, says the contractor who repaired it.

The low-level leak was discovered on November 5th, prompting all programs and services to be canceled and the facility to remain closed until November 29 at its Weyerhaeuser rink and December 2 at its Coulson rink. Accent Refrigeration Systems, a Victoria, British Columbia, contractor, which installed a low-charge ammonia system at the facility in April, fixed the leak and began remaking ice on November 22.

Communities with ice rinks in B.C. have been very wary of ammonia refrigeration since a catastrophic ammonia accident stemming from a neglected refrigeration system killed three technicians at a rink in Fernie, B.C., in October 2017. 

However, in regard to the leak at the Alberni Valley Multiplex, Art Sutherland, president and CEO of Accent Refrigeration, believes the facility could have reopened much sooner than it did.

“In reality the plant could have been safely run down in temperature overnight and shut down the following morning for a few hours to repair the leak, with no loss of ice time and no threat to the public,” he said. But the minor leak “was spun by news agencies into a 12in [30.5cm] crack to a defective chiller bought in China, with people running for the doors.”

Accent Refrigeration enhanced the safety of the facility in April when it replaced a flooded ammonia chiller using a 1,500lb (680kg) charge with a 210TR [739kW] atomizing spray ammonia chiller incorporating a 388lb [176kg] charge. The chiller was hydrostatically tested successfully at the factory and pressure tested to 110% at startup, said Sutherland. 

After six months of operation, a “very small leak” developed on a “weld where the shell meets the end flange,” said Sutherland. 

“At no time did the ammonia level in the compressor room go over 25ppm, which is the allowable level where a person can work without any respirators for eight hours a day,” he noted. “Most of the time the ammonia level was between 0 PPM and 15 PPM.”

Because the leak was under insulation, it took an Accent Refrigeration technician two days to discover it, said Sutherland, adding that during that period “the ammonia level in the compressor room was very minor with no need for respirators and only occasionally a detectible smell.”

Nonetheless, the B.C. safety authority (Technical Safety B.C.) dictated that the facility remain shut so that every weld on the chiller could be “non-destructive tested, including Magnaflux, Dye Penetrant and Shear Wave,” said Sutherland. This process kept the facility closed for a week while technicians and engineers were assembled. “No leaks or irregularities were found on any other joints,” he said.

The facility remained closed until clearance was given to create ice sheets at the two arenas on November 22.  Sutherland believes the closing the facility caused “significant loss to the community as they were hosting their largest annual fundraising hockey tournament, and their Junior A team lost three regular season games.”

“The negative ammonia hype in our province is overwhelming at times,” he said.

Sutherland acknowledged that ammonia systems need to be as safe as possible. “With a modern ammonia system such as the one in Port Alberni, there are several safeguards in place that would not allow a repeat of the unfortunate loss of life that took place in Fernie, B.C.,” he said.

“Ammonia is the best long-term choice for the environment and operating costs,” he added.

In reality the plant could have been safely run down in temperature overnight and shut down the following morning for a few hours to repair the leak, with no loss of ice time and no threat to the public."
– Art Sutherland, Accent Refrigeration



By Michael Garry

Dec 03, 2019, 17:50




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