On 10/13/2011 11:27 AM, TimR wrote:
On Oct 13, 12:16 pm, "John wrote:
What is the technical term for the putty that electricians use to seal
around service cables where they enter meter boxes, or pass through
walls?

*Duct Seal

It's Duct Seal, or as manufacturers call it, thumbgrade.

I have never heard it called anything but "duct seal", but lots of
products have different names in different areas. The last box I bought
was labeled "Duct Seal" (Panduit).

Where a conduit or sleeve goes between areas of different temperature
where "condensation is known to be a problem" an _"approved material"_
is required to seal around the wires or cables (300.7-A). The seal
prevents warm moist air from circulating to the cold area. Around here,
inside the service conduit into a building is always sealed. There are
other places where it is appropriate.

"Fire stop" is to maintain the fire rating of a wall or floor, but
should work.


We use it only to seal conduits going into hazardous areas. It will
prevent a dust explosion from propagating through conduit, at least in
theory.

Can't imagine protection to a hazardous area wouldn't require a seal-off
fitting with appropriate seal material. Can't imagine duct seal being
used as a hazardous seal.

--
bud--