Hydratight Eases Tension for Reactor Refurb

Ten years of disuse, great size and weight and.... four feet of sea water were three big problems facing Hydratight engineers on their latest refurbishment project.

The company's bolting and tensioning experts were called in when workers at a major chemical plant in Orange, Texas - a maker of very high specification plastics - discovered they needed to use their special, eight-inch stud-tensioning tool for the installation of a new reactor. The tool - from the old back-up reactor - had not been used in almost a decade, and after Hurricane Ike in September 2008, had been under four feet of salt water!

Luckily the huge device was well-known to Hydratight: it was designed and made by the company a decade ago specifically to tension the enormous studs on a specialist reactor vessel. The original commission had been for one of the company's biggest-ever tensioning tools, weighing 2,000 pounds and measuring forty inches high and twenty three inches in diameter. At eight inches, its stud capacity was double that of Hydratight's biggest standard rental item and remains one of the biggest tools of its kind the company - indeed any company - has ever produced.

The tensioner was needed during the rebuild of the reactor unit and Hydratight's specialists were given the job of rebuilding it from the ground up. No easy task!

Back at their workshop in Deer Park, Texas, they found the tensioner was in pretty bad shape.

"It was a mess," said applications engineer Lamar Monic. "The bridge and socket were badly rusted by the water, which made it hard enough to take apart. But the head was completely seized - we had to use two-by-four lengths of wood to turn the huge piston collar, which was over three feet in diameter!"

But Hydratight's technicians remained undaunted by the job: stripping the unit to its component parts took many hours - after which came the task of building it up like new again.

The rusted parts were cleaned and zinc-plated; the gearboxes completely stripped and rebuilt with new grease and every seal replaced before the unit was carefully reassembled for testing. The whole job took 42, labor-intensive hours.

A special test rig, built at Hydratight HQ in the UK, was shipped over to Hydratight Deer Park for a dry-run of the as-new tensioner - and it performed perfectly, to its original specification.

"This was a special job; very much one of a kind," said Monic. "But we handled it with the same precision and care we apply to far smaller, more delicate jobs. It was a remarkably powerful piece of equipment when we first made it and it remains so - even after the battering it took from the water.

"The customer was delighted with the result; the tensioner looked and performed like new," said Monic.