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Onis Line Blinds technology

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Hydrocarbon Engineering,

Improved safety, lower maintenance costs and increased production are three major challenges, however, thanks to Onis’ extensive experience and commitment to technology, each blinding operation can be provided with safe, efficient and economical solutions.

With over 30 years of proven performance, Onis Line Blinds outperform classical blinding solutions with its inline blind, operated by one person without any tools that within a few minutes can offer a 100% positive isolation.

Onis Line Blinds are mechanised figure-8, though safer and cheaper. Therefore, all the classical steps for blinding operations are required, including line depressurisation. Onis’ solution relies on the easy spreading/clamping motion that allows the slide gate to move frictionless from full bore to a blinded position in just a few seconds.

Making this critical operation safe is Onis’ top priority, so in order to avoid any handling errors, Onis has just patented a new slide gate whose design allows:

  • To move the slide gate only when the half-bodies are completely spread.
  • To clamp the half-bodies only when the slide gate is correctly positioned.

What is unique about the Onis Line Blinds

Although a figure-8 commands a gap of a 0.5 in. inline, Onis pipe spread is limited to 0.16 in. There are no internal seals or moving parts of any kind, only four seals, all on the slide gate, ensure the sealing of the line. The advantage is that gaskets can be inspected, and easily replaced if needed, out of process.

Moreover, Onis’ self-locking design makes it inherently safer because if there is extra pressure the line blind will eventually clamp even more. Last but not least, each blind is tailor made with 100% forged European steel, providing some of the highest quality in the market.

Which projects

Last year, Onis Line Blinds were installed on a steam cracker’s eight furnaces feed lines and decoking lines, resulting in shutdown blinding reduction from 12 hours to one hour and an increased revenue of US$2.8 million more for the plant in a year.

In early 2016, four Line Blinds of 30 in. were installed on a flare network in Spain, limiting blinding operations and gas emissions from eight hours to five minutes.

Adapted from press release by Francesca Brindle

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