Type D gaskets are insulating ring joint gaskets made to fit the ring groove of Ring Type Joint flanges. The Type D central gasket is made of medium weave fabric-reinforced phenolic, manufactured to ASA (ANSI) gasket dimensions. Properties are similar to those of phenolic flat central gaskets and are available in the basic octagonal shapes. Oval shapes can be ordered by special request. When installing Type D gaskets, it is also recommended that tape be wrapped around the outside of the flange to prevent foreign material from lodging between the exposed portions and causing "shorting out" of the flanges. Alignment pins should be used whenever possible to assure proper alignment of flanges when installing all flange insulation sets. Pins should be a minimum of 3/32" (2.38mm) larger than the bolt size.
Gasket Materials
|
Material |
Dielectric strength |
Compressive strength |
Water absorption |
Tensile strength |
Operating temp (oC) |
|
Plain Phenolic |
500 vpm |
25000 psi |
1.6% |
20000 psi |
-54-104 |
|
Neoprene Faced Phenolic |
500 vpm |
25000 psi |
1.6% |
20000 psi |
-54-79 |
|
Reinforced PTFE |
350 vpm |
2300 psi |
0.01% |
1450 psi |
-196-260 |
|
G7 |
350 vpm |
40000 psi |
0.07% |
25000 psi |
-196 to 232 |
|
G10 |
550 vpm |
50000 psi |
0.1% |
45000 psi |
-196 to 138 |
|
G11 |
550 vpm |
50000 psi |
0.1% |
43000 psi |
-196 to176 |
G-7 material should not be used with hydrocarbons, not even trace amounts.
Type D Flange Insulation Gaskets are suitable for RTJ flange, they can be produced according to ASME and API flange standard.
