In the 1970's there was no such product as
Non-asbestos gasketing. Asbestos was the product of the day
and why not, it was effective, low cost and as long is it was
handled properly it was safe.
In the 1980's asbestos became a dirty word, and for
good reason it caused cancer. The problem was the baby got
thrown out with the bath water. The asbestos in asbestos
gasket material was embedded in the rubber it was blended with so,
unless you took a grinder to the material to separate the asbestos
out and then breathed in the asbestos (which could be avoided
by oiling or wetting the material first), it was not going to hurt
you. Even so, the lawyers got to work on it and effectively
killed the industry. The only remaining manufacturing of asbestos
gasket material is off shore. Today, very few distributors in
the USA will carry it (including this one) most will only sell
non-asbestos gasket materials. American Seal & Packing has never
sold any asbestos product and only sells non-asbestos compressed
Johns Manville took the biggest hit, once the
largest distributor of gasket material in the Untied States (JM 60
was a standard), their liability was the worst since they also
produced asbestos insulation. The asbestos fibers were easily
released from insulation and easily breathed in. Johns
Manville eventually declared Chapter 11 and sold off divisions.
The gasket material division was later reformed as a portion of
JM Clipper and no longer sold asbestos.
In the 1980's the industry was prone. The
first company to come out with a quality non-asbestos substitute and
to market it well was Garlock. At the time Garlock was the
number two seller of compressed asbestos gasket material (number 3
was Durabla Manufacturing). Garlock came out with their "Blue Guard"
line and although it was not as good as asbestos in many
applications it was better than a potential law suit. Before
long Garlock was number 1. U.S. Gasket material customers were
afraid of purchasing any asbestos containing product. With the
exception of the Oil refineries.
The refineries took their case to the supreme court
and won the right to maintain the use of asbestos gasket material
since no other product at the time was proven to be as effective.
It did not make sense to protect workers from asbestos but not
protect them from a failed gasket which in some applications (such
as a steam line) can cause death. People have been cut in half
by walking past a leaking steam flange due to gasket failure.
The refineries won and continued to use asbestos until they finally found non-asbesto replacments.
Durabla Manufacturing's "Durabla Black" is no longer produced. Production of Durabla Black ceased in 2012.
Most of todays non-asbestos gasket materials contain
either Kevlar, an aramid fiber, fiberglass, carbon, graphite or
another mineral fiber. Todays major manufacturers include: Garlock,
Gasket Resoures Inc., and Thermoseal (previously Klinger USA) . Most of
the manufacturers are now producing off shore. Garlock produces sheet in Mexico (Gylon in USA), Gasket Resources Inc. produces in Canada, Thermoseal produces domestically in Ohio (USA) and Internationally. Sourcing of course is a dynamic situation and subject to change.
Regardless of the manufacturer, the basics are the
filler and the elastomer used. While no two compounds (or the
% of filler) are identical, the basic Elastomers are: NBR (Buna-N),
SBR, EPDM or Neoprene. If you examine which material you need (as
defined by the application) and select the non-asbestos gasket
material with that elastomer you will usually do well. This
method will also allow you to select a competitive brand that will
serve your application. No two materials are identical so
caution must always be exercised. In general the common "Binders"
NBR - good for oils, gas, mild chemicals and
SBR - good for saturated Steam, mild chemicals inert
gas and water
Neoprene - good for saturated steam, refrigerants,
oils, fuels, mild acids and alkalies and water.
EPDM - good for saturated steam, mild chemicals and
Each material listed regardless of manufacture will
indicate the "Binder" which makes cross referencing equal materials
a much easier task. You should however pay attention to
Tensile strength (for pressure resistance) Temperature ratings, and
Compression / Recovery ratings.
You must also consider Size, Temperature,
Application, Media, Pressure, Speed (if dynamic) of your
specific application. If this is for a finished gasket you
will also want to consider bolt loads, the size of bolts, the number
of bolts, the bolt material and the available torque.
We at American Seal & Packing can assist you with a
material selection of non-asbestos gasket materials or sell to you a
non-asbestos gasket material on-line at ww.sealsales.com.
We can also offer a number of non-asbestos gasket manufacturers
products to meet your specifications.