PTFE enveloped gasket

TOMBO™ No. 9010series


A PTFE-wrapped gasket that is made by covering the core material such as a joint sheet with a PTFE outer skin.
The sealed surface is completely covered in a PTFE membrane. It has excellent anti-staining properties and chemical resistance, and therefore it is used for a broad range of applications including fine chemicals, petrochemicals, the pharmaceutical and food industry, and general manufacturing.

Product Category

Gaskets & Gland PackingSheet Gaskets


Chemistry & PetrochemistryOil Refining & PetrochemistryChemistryResidential Housing & Non-ResidentialBuilding FacilitiesVarious Plant FacilitiesPiping

Applications, corresponding standard, indication, usage precautions

Various corrosive fluids and organic solvents
Pollution-sensitive fluids
The parts that need electrical insulation

Corresponding Standard


Example of TOMBO No. Indication

Precautions for use
Depending on the type of fluid, the fluid inside the gasket may ingress through the PTFE covering material. Particularly the likes of nitric acid, ethylene oxide, halogen (chlorine, bromine, etc.), molten sulfur, or monochloroacetic acid will soak into the core material by permeating due to use over a long time and the gasket may lose its functionality.
In such circumstances, Nichias recommends immediately replacing the gasket or using a PTFE Solid Gasket.
For other precautions, see the “Gaskets” section of the catalog.

Outer skin shape and core material

Outer skin shape Indication symbol
A Basic shape A
B Model compatible with large diameters B
AS Right-angle shape AS
KA Made of knitted material around the outside KA
KB Made of knitted material around the outside
(Model compatible with large diameters)
KS Made of knitted material around the outside
(Right-angle shape)
RA Welded around the outside RA
RB Welded around the outside
(Model compatible with large diameters)
RS Welded around the outside
(Right-angle shape)
Requested shape Z
Core material Indication symbol
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
Requested material Z

*There are also types that use rubber for the core.

Applicable dimensions and core structure

Applicable dimensions Indication symbol
Dimensions of Nichias standard S
Standard dimensions of NAFLON liningNote 1 F
Standard dimensions of glass liningNote 2 G
Standard dimensions of electrical insulation gasket E
Requested dimensions Z
Note 1: The standardized product at Nichias. For details, please check the dimensions table below.
Note 2: The applied flange is an FL JPI Flange made by AGC Technology Solutions Co., Ltd.

Corrugated core structure
Corrugated core structure Indication symbol
表示記号なし Alone Indication symbol
H With pattern H
D 2 pieces D
C With corrugated board C
P With flat board P
Requested structure Z


  • TOMBO is a registered trademark or trademark of NICHIAS Corporation.
  • Name of products with "®" are registered trademarks of NICHIAS Corporation.
  • Name of products with "™" are trademarks of NICHIAS Corporation.