The TEADIT® plant has manufactured spiral-wound gaskets since 1965. It is located in the largest and most progressive industrial and metallurgical complex in Brazil. In 1975, TEADIT® moved into its present, modern facilities. The plant was further enlarged in 1982 when TEADIT® merged with another company which was engaged in the manufacture of metal expansion joints, shock absorbers and special bellows. Today, TEADIT® is one of the largest fabricators of spiral-wound gaskets, expansion joints and bellows in the world.
This is simplest style of spiral wound gasket, consisting of a circular winding without centering or inner rings. Spiral wound gaskets Style 911 are mainly used in tongue and groove or male and female. They are also used in equipment with space and weight limitations. Style 911-T has better sealability than a coventional heat exchanger double-jacketed gasket. However, a specially machined groove with an appropiate compression stop in needed for 911-T.
A style 911-M gasket is a sealing winding with an inner ring. The purpose of this ring is to fill out the space between the flanges, avoiding turbulence in the flow of the fluid or as a protection against corrosion or erosion. It is also used as a compression limit when the seating stress is greater than 30,000 psi (210 MPa). Gaskets with PTFE filler have a tendency to inward buckle thus the use of an inner ring is recommended if the gasket is to be installed with a non-confined inside diameter.
The construction of this gasket is circular metal winding with an outer guide ring. The sealing element is made of the specified metal and soft sealing material. The standard pipe size gaskets are made to ASME B16.20 (see also style 913M). These gaskets are used in a very wide variety of applications.
Style 914 spiral wound gaskets are windings in non-circular forms like oval, rectangular and square with rounded corners, diamonds, oblong or pear shaped. Style 914 gaskets are used in boiler handholes and manholes, equipment, engine head-gaskets and exhaust systems. Inner rings should also be used for many of these applications.
The specific needs of oxygen service applications were taken in consideration while developing Style 913M-OX, to make it the ideal sealing solution for oxygen-type service, such as GTL environments, where fire-safe design is essential. The Style 913M-OX spiral wound gasket is manufactured in a controlled and cleaned environment to insure the finished product is free from organic contaminants. It is typically produced from 316L stainless steel strip, inner and outer rings and high purity flexible graphite filler with oxidation inhibitors. The material selection and the manufacturing procedure developed for this gasket allows it to have the properties needed for Oxygen service, assuring a safe operation and low leak rates.
For specific applications where crevice corrosion is a concern, Teadit® 913M-CMP is a superior choice. This design is based on an ASME B16.20 spiral wound, but with a camprofiled Monel® inner ring. The inner ring can even be sized to the bore. Typical application is for HF Alkylation Service, however, different metallurgies can be selected for superior corrosion protection in multiple conditions. Flexible Graphite (FG) and Expanded PTFE (ePTFE) may be selected for filler material in the spiral wound portion. For the camprofiled inner ring, standard 0.020” (0.5 mm) facing is utilized, where FG is selected for the covering material. To enhance crevice corrosion protection, 1/16” is utilized, where ePTFE is selected. Typical NPS/Pressure Class applications are for Class 150 and Class 300 assemblies.
The 913M is the standard spiral wound gasket with an inner ring. The purpose of this ring is to fill out the space between the flanges, avoiding turbulence in the flow of the fluid or as protection against corrosion or erosion. It is also used as a compression limit. Gaskets with PTFE filler have a tendency to inward buckle thus the use of an inner ring is required by ASME B16.20. Inner rings are also required with ASME standard spiral wound gaskets with flexible graphite fillers unless the purchaser specifies otherwise and some sizes and pressure class require inner rings regardless of filler material.
Teadit® Camprofile gaskets offer outstanding flexibility, assuring seal integrity under pressure and temperature fluctuations, flange rotation, bolt stress relaxation and creep.
Teadit® Camprofile gaskets are used by the chemical and petrochemical industry, as well as in power stations and refineries, on both standard pipework and special applications, e.g. shell and tube heat exchangers, etc. Camprofile gaskets are constructed from a precision serrated metallic core with soft facing materials - flexible graphite or expanded PTFE - bonded to either side.
Depending on the kind of metal used, Teadit® Camprofile gaskets can be used for all media from pH 0 to 14.
The core material should be chemically and thermally compatible with the fluid to be sealed. If possible, the core metal should be the same as used to manufacture the flanges to avoid corrosion or differential Thermal Expansion.
The most widely used covering material is Flexible Graphite. For operational conditions where Flexible Graphite is not recommended Expanded PTFE is used.
The chart below shows the Temperature and Pressure limits for the cover materials.
Jacketed Gaskets
Style 926 is similar to style 923 but the metallic jacket is corrugated. The corrugations act as a labyrinth. The filler material is typically flexible graphite, or other soft materials.
Style 929Style 929 is similar to style 926 with a corrugated metallic filler. Used in applications where it is necessary to have a gasket without non-metallic materials, temperature limits and chemical resistance depend upon of the metal only.
Jacketed Gaskets
Style 923 is a flat double jacket gasket. Its most typical applications are in Heat Exchangers. ASME B 16.20 shows the gasket dimensions for ANSI B 16.5 flanges. The standard thickness is 1/8 in (3.2 mm). This style is also used in large size reactors in chemical plants. Another important use is for flanges in the large, low pressure ducting in Steel Mill Blast Furnaces. To compensate for distortions and irregularities of these flanges gaskets have the thickness from 5/32 in (4 mm) to 1/4 in (6 mm).
Style 927Style 927 is similar to style 923 with addition of flexible graphite facing.
Sealing solutions for industries
Style 905 Metalbest is a corrugated gasket style 900 metal core with Flexible Graphite facings (see figure below). It combines the sealing properties of the Flexible Graphite with the extrusion resistance of the corrugated metal core. The main advantage for using a 905 Metalbest is that it provides an extremely effective seal under low bolt loads. This makes the gasket ideal for applications where the available loading is determined to be low and unsuitable for spiral wound or other type of gasket requiring high seating stress. It is designed to maintain a positive seal through thermal cycling and shock load conditions. These gaskets have passed an industry fire test, a relative indicator of the gasket's ability to resist fire conditions.
The standard material for the metal core is Austenitic Stainless Steel. Other alloy are available upon request.
Style 905 Metalbest Gaskets for Heat Exchangers
One of the most frequent uses of Style 905 Metalbest Gaskets are in Shell and Tube Heat Exchangers, due to their ability of to avoid mechanical shearing problems associated other gasket types in heavy thermal cycling applications. The standard core material is Austenitic Stainless Steel and the covering layer is Flexible Graphite. Other alloys are available upon request.
For customers requiring expanded PTFE facing material instead of graphite, style 905-ePTFE is available in thicknesses as required.
