Shannon Global Energy Solutions has developed a new hydrophobic thermal and acoustic insulation blanket to reduce energy loss and/or mitigate harmful noise levels from equipment such as valves, pumps, heat exchangers, vessels and compressors with geometrically complex surfaces at refineries and processing plants. The new blanket designs – which contain Lewco Super Mat, a PTFE-impregnated Type-E needled and felted fibreglass blanket insulation – do not require workers to wear a mask while manufacturing or installing the material. Super Mat helps mitigate corrosion under insulation (CUI) due to its water-repelling properties.
The hydrophobic thermal blanket, designs LT450TT-HES and LT450TT-HS, and hydrophobic acoustic blanket, designs LT450A-TT-HES and LT450A-TT-HS, have an insulating core made of hydrophobic Super Mat consisting solely of PTFE and E-glass fibre, which means there is no amorphous silica particulate or additive that can escape as dust, posing a health risk. The blankets reduce harmful noise levels by up to 15 dBA. Depending on thickness, Shannon calculates the surface temperature of its thermal blanket when wrapped around a component operating at 450°F (232°C) will range from 108°F (42°C) to 135°F (57°C). The blanket designs encapsulate the Super Mat insulation core with various jacketing materials, including PTFE-impregnated fibreglass cloth commonly used for applications at processing plants.
The PTFE coating of every glass fibre gives Super Mat its hydrophobicity, or ability to repel water. Hydrophobic insulation reduces the risk of CUI by significantly reducing or eliminating the steel substrate’s duration of wetness caused by water-soaked insulation. When water absorbent insulation becomes wet, it not only lacks the ability to conserve thermal energy, but also holds that water against the equipment, which increases the risk of CUI. Super Mat’s hydrophobic performance is validated by ASTM test methods C1511 and C1763.
“If insulation gets wet enough, it will corrode a steel substrate and lead to thermal efficiency degradation,” says Monica Chauviere, president of Monicorr, a consultancy providing expertise on CUI and thermal insulation, which she founded after retiring as an ExxonMobil engineer. “A higher volume percentage of water inside the insulation requires more heat energy to reach vaporisation. The insulation’s deteriorating thermal conductivity offsets the accumulating heat energy, which comes from the equipment, and creates this double whammy.”
“Since the 1970s, blanket manufacturers have used E-glass insulation mat because of its quality and safety; it doesn’t require respiratory masks and body protection to avoid unwanted exposure,” says Frank Kovacs, president and CEO of Shannon. “E-glass is the most widely accepted and specified insulation core material because it’s the safest and most durable. It’s one reason our blankets have earned a reputation for high quality.”