PSI LineBacker® Sealing Gaskets utilize a patented rectangular sealing element, referred to as a “quad” ring, in combination with a unique groove design to effectively seal and isolate flanges of all types. This unique design provides elastic memory. Materials such as polyimide, TFE (Teflon) and vinyl may be used as sealing elements, which dramatically increases the options available for matching gasket materials to service and environmental conditions. A much broader range of retainer material/seal element combinations may therefore be used for excellent temperature and chemical range compatibility.
Features of the LineBacker® Sealing Gasket:
Eliminates flange leaks.
Guards against blowouts.
Protects against fire and hostile environments.
Usable with any type of flange.
Matches gasket materials to service conditions.
Lowest possible clamp and compressive load.
Increases gasket life.
Insulating version is both a positive seal and a superior insulator.
Available in all standard ANSI and API flange sizes from 1/2” and above.
Available in custom or odd sizes and shapes.
Available in pressure ratings for all ANSI and API rated flanges.\
For pressures from hard vacuum to 50,000 psi and higher.
How LineBacker Works
Before Tightening
The flange faces come into contact with the sealing elements, which extend slightly above the surface of the retainer. As the flange is tightened the sealing elements are compressed and move sideways into the inclined portion of the groove, developing a high unit pressure against the flange faces.,
After Tightening
The flange faces have come into firm contact with the retainer, thus encapsulating the sealing elements within grooves. At the same time, the unique LineBacker seal configuration provides elastic memory for elastomers not normally associated with this characteristic - resulting in a simple flat gasket with extremely high loading and self energizing characteristics without adverse cold flow problems.,
Wide Choice of Materials
LineBacker® gaskets are available in a wide variety of retainer and sealing element combinations for matching gaskets to service and environmental conditions. This greater variety of materials also provides excellent temperature and chemical range compatibility.
Metal Retainer Materials |
Insulating Retainer Materials |
Sealing Elements |
Aluminum Brass Carpenter 20 Carbon Steel Cast Iron Clad Steel Materials Copper Ductile Iron Hastelloy B Hastelloy C Hastelloy X Inconel X Monel Nickel 200 Soft Iron Stainless Steel Tantalum Tin Titanium Vanadium |
Ceramic Epoxy Glass Glass Lucite Melamine Phenolic Polyester Glass Polyethylene Polyphenol Ether Pyrox Silicone Glass Vinyl |
Buna-N (Nitrile) Buna-S Butyl EPDM Hypolon Kel-F Natural Rubbers Neoprene Nylon Polyimide Polyurethane Silicone Rubber Teflon* Vinyl Viton*
*DuPont |
Suggested Sealing Gasket Material Compatibility
Medium |
Retainer |
Seal |
Temperature Range °F |
Temperature Range °C |
Acetone |
Phenolic |
Nitrile |
+32 to +80 |
0 to +27 |
Air |
G-10 |
Nitrile |
-65 to +225 |
-54 to +107 |
Ammonia Dry |
G-10 |
Teflon |
-65 to +220 |
-54 to +104 |
Ammonia (Wet)*** |
G-10 |
Teflon |
+32 to +100 |
0 to +38 |
Bleach |
G-10 |
Teflon |
+32 to +80 |
0 to +27 |
Butylene (Butidiene) |
G-10 |
Teflon |
+32 to +100 |
0 to +38 |
Carbon Dioxide |
G-10 |
Nitrile |
+32 to +150 |
0 to +66 |
Caustic Soda (NaOH) |
G10 |
Teflon |
-65 to +225 |
-54 to +107 |
Cryogenic |
G-10 |
Teflon |
-300 to +280 |
-184 to +138 |
Ethanol |
G-10 |
Nitrile |
+32 to +100 |
0 to +38 |
Ethylene (Ethene) |
G-10 |
Teflon |
+32 to +80 |
0 to +27 |
Fuel Oil |
G-10 |
Viton |
-20 to +280 |
-29 to +138 |
Gas, Natural |
Phenolic |
Nitrile |
-65 to +220 |
-54 to +104 |
Gas, Sour |
Phenolic |
Viton |
-20 to +220 |
-29 to +104 |
Gasoline |
G-10 |
Teflon |
-65 to +225 |
54 to +107 |
Hydrogen |
G-10 |
Nitrile |
-65 to +250 |
-54 to +121 |
Jet Fuel |
G-10 |
Viton |
-20 to +225 |
-29 to +107 |
LNG |
G-11 |
Teflon |
-300 to +100 |
-184 to +38 |
Mercaptan |
G-10 |
Teflon |
-20 to +80 |
-29 to +27 |
Methanol |
G-10 |
Teflon |
+32 to +100 |
0 to +38 |
MTBE |
G-10 |
Special Nitrile |
+32 to +80 |
0 to +27 |
Nitrogen |
Phenolic |
Nitrile |
-65 to +220 |
-54 to +104 |
Oil, Crude |
G-10 |
Viton |
-20 to +280 |
-29 to +138 |
Oxygen** |
G-10 |
Teflon |
-65 to +250 |
-54 to +121 |
Pentane |
G-10 |
Teflon |
+32 to +80 |
0 to +27 |
Propane |
G-10 |
Nitrile or Teflon |
+32 to +80 |
0 to +27 |
Propylene |
G-10 |
Viton |
+32 to +80 |
0 to +27 |
Sewage |
G-10 |
Viton |
-20 to +280 |
-29 to +138 |
Spent Liquor |
G-10 |
Teflon |
+32 to +100 |
0 to +38 |
Steam* |
G-7* |
Teflon |
to +450 |
To +232 |
Steam |
G-3 |
Teflon |
to +392 |
To +200 |
Steam* |
Yellow Jacket |
No Seal |
to +450* or +392 |
to +268* or +200 |
Styrene |
G-10 |
Teflon |
+32 to +80 |
0 to +27 |
Sulphur (Molten) |
G-10 |
Teflon |
+32 to +280 |
0 to +138 |
Toluene |
G-10 |
Viton or Teflon |
+32 to +150 |
0 to +66 |
Water (Hot) |
G-10 |
Nitrile |
+175 to +250 |
+79 to +121 |
Water (Potable) |
G-10 |
Nitrile |
+32 to +250 |
0 to +121 |
Water (Sea) |
G-10 |
Nitrile |
+32 to +250 |
0 to +121 |
White Liquor |
G-10 |
Teflon |
+80 to +280 |
+27 to +13 |