Couplings - Eoss.com

GasketsSECTION 14: GASKETSGasket PerformanceUNIQUE C-SHAPED GASKETFORMS A TRIPLE SEALSEALS BETWEEN THE PIPE ENDSAND THE GROOVESURROUNDED, REINFORCED ANDSLIGHTLY COMPRESSED BY THE HOUSINGSEAL IS ENHANCED BY PRESSUREOR VACUUM IN THE LINEThe sealing efficiency of Victaulic gaskets is such that the gasket forms an initial sealas it is stretched over the pipe ends. Upon placement of the housing around the gasketand into the grooves, the gasket is positioned. As the housing segments are tightened,the resilient elastomeric gasket conforms to the internal cavity of the housing and isfurther compressed, enhancing the gasket’s seal against the pipe. The Victaulic gasketis pressure responsive.The combination of these characteristics creates a permanent, leak-tight triple sealon a variety of piping materials including carbon steel, stainless steel, aluminum,PVC and copper. Line pressure serves to strengthen the seal through the combinationof normal gasket resilience, housing reinforcement and the action of pressuredownward on the lips.Vacuum Service – The Victaulic gasket design seals equally well under pressure orvacuum. Vacuum creates a pressure differential between the inside and outside of thepiping system. The resulting increased force from the external pressure has the same sealenhancement effect as internal pressure. For continuous vacuum service greater than254 mm/10" of mercury, we recommend the use of molded Victaulic FlushSeal gasketsor Victaulic standard gaskets with a metal ring liner, both available from your Victaulicdistributor. The FlushSeal feature and the metal liner both prevent distortion of thegasket due to the pulling action of a high vacuum at the center of the gasket.Either molded FlushSeal gaskets or gaskets with metal liners are recommended onstrong vacuums and are suitable for applications wherein vacuum conditions areanticipated to a maximum value of 760 mm/29.9" of mercury.ANSI/NSF 61 and Australia Watermark Standards – ANSI/NSF 61 and AustraliaWatermark are National Standards that were developed to establish minimumrequirements for the control of potential adverse human health effects from productswhich contact drinking water. Their primary focus is on contaminants or impurities whichmay be imparted indirectly to drinking water. Materials that do not come in directcontact with the potable water do not require evaluation. The classification categoriesfor pipe and related products and joining and sealing materials, as established byANSI/NSF 61/Australia Watermark are “cold”, which is limited to +30°C/+86°F maximumand “hot” which is limited to +82°C/+180°F maximum. These categories were establishedby the maximum ambient distribution temperature of unheated water for “cold” and atemperature well in excess of a scalding temperature for “hot” domestic water.The following list represents the current classifications on our products:EPDM “E” Gaskets: UL classified in accordance with ANSI/NSF 61/Australia Watermarkfor cold +30°C/+86°F and hot +82°C/+180°F potable water service.Halogenated Butyl “M” Gaskets: UL classified in accordance with ANSI/NSF 61/Australia Watermark for cold +30°C/+86°F potable water service.PPS Coating: The PPS (Polyphenylene Sulfide blend) coating applied to ourVic-300 AGS butterfly valves is UL classified in accordance with ANSI/NSF 61/AustraliaWatermark for cold +30°C/+180°F and hot +82°C/+180°F potable water service.14-3WWW.VICTAULIC.COM