Exploring Insulation Materials: Poured-In-Place and Reflective Insulations

October 1, 2013


poured-in-place insulation for underground piping, ducts, and tanks is
available. These are granular materials generally made from engineered blends
of inorganic materials or calcium carbonate and require no mixing or curing.
The hydrophobic materials provide thermal insulation, corrosion protection, and
load-bearing properties. Product is sold by the cubic foot and is available in
a variety of packaging options. The material is installed around underground
pipes, ducts, or tanks before backfilling. Currently, no ASTM standard material
specifications have been developed for these products.

Reflective Insulations

Reflective insulations
are defined by ASTM as insulation depending for its performance upon reduction
of radiant heat transfer across air spaces by use of one or more surfaces of
high reflectance and low emittance. Reflective insulations utilize
low-emittance foil (usually aluminum) or foil-coated facings to reduce the
amount of radiant heat flux occurring at the surface.

While reflective
insulations obey the same laws of physics as any insulation system, they are
typically relatively thin (usually less than ½”). Thus, they present little
resistance to conduction heat transfer through the material.
They operate primarily by reducing the radiant heat flux to and from the surface
of the insulation. Reflective foils are often used as facing on other, more
conventional insulations to provide additional thermal resistance. The
Reflective Insulation Manufacturers Association (www.rima.net) is a source
of additional technical information on reflective insulation products.

ASTM C667 Standard Specification for
Prefabricated Reflective Insulation Systems for Equipment and Pipe Operating at
Temperatures Above Ambient Air covers prefabricated, multi-layer reflective
insulation systems for equipment and piping.