Insulating High Temperature Systems

When it comes to insulating your pipes, there are anyapplication at this temperature would be super-heated
factors to take into consideration. Take temperature,steam for turbines in power plants.
for instance. How hot are your pipes? Imagine your- 550+ F: There are several options at this
thermos of coffee - it does a great job of keepingtemperature level, including a plain fiberglass cloth, a
your java piping hot all day long. But pour in somestainless steel mesh or a silica based cloth. All of
super-heated liquid at 1,000 degrees F and watchthese options are slightly more expensive than the
your thermos melt away into a puddle of plastic.TEFLON/fiberglass covering. The real tradeoff,
Different insulation materials are made for differenthowever, is that they do not have any water or
temperatures, both for the covering material and theabrasion-resistant coating. This is a problem, because
insulation material itself.sometimes you get leaks in pipes, and the
Covering Materialswater-resistance coating keeps the insulation from
The insulation industry typically divides coveringgetting wet. Once wet, the insulation is ruined. These
materials for insulation into three temperatureparticular cloths are used for the hot side of the
buckets: 450 degrees F and less, 450 to 550 F, andinsulation jacket. For the cold side, the TEFLON
over 550 F. High heat applications are those that arefiberglass composite or the silica based cloth can be
450 degrees F and hotter.used. If the TEFLON/fiberglass composite is used,
- Up to 450 degrees F: The covering material for thisthere is the added benefit of the water- and
temperature range is a silicone impregnated fiberglassabrasion-resistant coating. However, the silica based
cloth (fiberglass/silicone composite) on the outsidecloth is often chosen for its versatility in high
covers of the insulating jacket. Remember, this is nottemperature applications. An example of an
a high heat application, so the same material is usedextremely high temperature application is an
on both the "hot" side and the "cold" side. The hotemergency generator, like you would see at a
side is usually the one that is inside (near the pipe, forhospital (where people can't afford to see their
example) and the cold side would be the outerbedside equipment turn off when the local power
portion of the cover. A steam room for heating is acompany has an outage). Insulation Materials
typical situation with this level of heat.While the industry divides the covering materials into
- 450 to 550 F: At these temperatures (nowthree temperature ranges, there are only two
considered high heat), a TEFLON/fiberglass compositecategories for the actual insulation: up to 1,200
is used on the hot side. This material has a higherdegrees F and more than 1,200 degrees F.
temperature limit, while still being less expensive than- Up to 1,200 degrees F: In this temperature range,
the next hot step up. The fiberglass/siliconeneedled fiberglass insulation is used. Needling is the
composite can still be used on the cold side, in mostprocess of sticking actual needles into the fiberglass,
situations. However, there are some instances whereresulting in a mechanical bond among the fibers. This
the TEFLON/fiberglass composite would also be usedis in contrast to resinous or inorganic binders that can
on the cold side. The decision depends on thedeteriorate under high heat or shake apart in vibrating
atmosphere -- if the application is in a chemical plantapplications.
that has a very acidic, corrosive atmosphere, the- 1,200+ F: For any applications that reach
TEFLON/fiberglass covering is used on both sides.temperatures above 1,200 F, a needled amorphous
This way the pH of the atmosphere does not eatsilica insulation is used.
away at any of the covering. A good example of an