RAMCO® Spra-Gard®
Safety Shields, the work horse of safety shields, are most frequently
specified because of their wide range of physical characteristics.
RAMCO® Spra-Gard®
Safety Shields are fabricated in three proprietary thermoplastic
textiles:
Teflon*
(tetrafluoroethylene or TFE coated fiberglass)
Polypropylene
(PPL)
ECTFE
The two woven
cloths — TFE and PPL —are
developed exclusively for RAMCO® according to specifications.
These fabrics are produced to a patented design and a “porosity
concept’’ that has been very carefully engineered. Rather
than using impenetrable fabrics, Spra-Gard® Safety Shields are
made of slightly porous textiles — too slight to permit a
sprayout but sufficient to allow fluid to seep through to the indicating
patch in the event of a leak.
ECTFE,
a fluoropolymer clear film, is the material that forms the wide
center band of the Spra-Gard® “See-Thru” Shields.
This non-flammable film withstands temperatures up to 300°F
(150°C) and has very high tensile strength.
It also demonstrates excellent chemical resistance.
Another common
feature of Spra-Gard® Shields is the sensitive pH patch or indicator
that is incorporated in each safety shield. Should the slightest
amount of leaking fluid come in contact with the patch, the patch
undergoes color change immediately signaling trouble in the line.
Yellow/orange in color, the indicator turns brilliant red with an
acid leak and bright green with an alkali leak. While the affected
patch can no longer be used, it can be removed and replaced with
another patch after the shield has been neutralized. The shield
is then ready for reuse.
Spra-Gard®
Safety Shields have an overlap design. The shields wrap around the
pipe connections completely to prevent a lateral sprayout. During
installation, they are held in place by means of a velcro fastener.
No tools are required, and a single installer can secure a shield
over a flange or valve in less than a minute.
Each
shield has a pair of tie-down cords. After it has been positioned
over the joint and held firmly by its velcro fastener, the cords
are drawn tightly around the pipe and secured with a square knot.
Use of a square knot is essential, since pressure exerted against
a square knot will tighten, ensuring that the shield will maintain
its position over the pipe connection.
All Spra-Gard®
Shields have been subjected to ultraviolet (UV) testing and have
performed without degradation for approximately 500 hours.
Material is
considered acceptable if it withstands approximately 200 hours of
exposure without degradation. This is equivalent to approximately
four to five years of outdoor exposure in the tropics and even longer
in a temperate zone. Thus, Spra-Gard® Shields are inhibited
against ultra-violet rays and can be installed both indoors and
outdoors.
Other critical
features of RAMCO® Spra-Gard® Safety Shields are their ability
to resist ignition and flame propagation.
Because each
Spra-Gard® Safety Shield is produced from a different thermoplastic
cloth, parameters for pressure and temperature
tolerance and chemical resistance vary.