Metallic ring joint gaskets are design for high pressure application. They are available in a variety of forms to suit different flange formats. RTJs come in two type an Oval and an Octagonal cross sections. These basic shapes are used in pressure up to 10000 psi. The octagonal Cross set a higher sealing efficiency the Oval.
At Vrushabh Engineering, we manufacture Spiral wound gaskets by spirally winding a preformed metal strip and filler on the outer periphery of metal winding mandrels whose outside diameter form the inner diameter of the gasket and superposed metal and non-metallic windings are continually wound until the required outer diameter is attained.
Compatible with the flange closure in which it is to be used, spiral wound gaskets can be used over the complete temperature range from cryogenic to approximately 2000°F and in all pressures from vacuum to the standard 2500 psi flange ratings making it a high pressure and high temperature gasket. They are more resilient than any other type of metallic gasket with higher flexibility and recovery characteristics to maintain a seal under variable working conditions.
Bridging the gap between metallic gaskets and soft gaskets, the semi-metallics combine features of each. Those gaskets are composites of metal and non-metallic materials. The metal is intended to offer strength and resiliency while the non-metallic portion of a gasket provides conformability and sealability Commonly used semi-metallic are spiral wound, metal jacketed, Cam profile and a variety of metal-reinforced graphite gaskets.
Semi metallic gaskets are designed for the widest range of operating conditions of temperature and pressure. Semi-metallic are used on raised face, male-andfemale and tongue-and –groove flanges.
Spiral wound gaskets are used for high temperature and high-pressure applications. The main parts of spiral wound gasket are metallic windings and filler material. The criteria for material selection of windings are: corrosive nature, fluid concentration, operating temperature and material cost. Commonly used material for winding are Stainless steel 304, 316 and 321.Alternate winding materials also can be used depending upon the services. General filler material used are Asbestos and graphite. Graphite filler are recommended for very high temperature application.
For proper positioning, spiral wound gaskets are provided with outer centering ring made up of Carbon Steel. In Vacuum service application they are provided with inner ring. The material of the ring should be compatible with the process fluid.
Spiral wound gasket is recommended with flange face finish of 63-250 AARH.
At Vrushabh Engineering, we manufacture Non-metallic flat gaskets from arimid fiber, glass fiber, elastomer, Teflon (PTFE), graphite etc. according to ASME B16.21 which covers types, sizes, materials, dimensions, dimensional tolerances, and markings for non-metallic flat gaskets.
At Vrushabh Engineering, the following information shall be included in markings: manufacturer’s name or trade mark or material designation. Gaskets shall be packaged with NPS, class, gasket manufacturer’s name, material designation, thickness and ASME B16.21 marked or tagged on the package or the gasket. At the option of the manufacturer the DN designation may be included.
NPS followed by a dimensionless number is the designation for nominal pipe size as described in ASME B36.10M and is related to the reference nominal diameter DN used in international standards. Class followed by a dimensionless number is the designation for common flange pressure-temperature ratings as given by the referenced flange standards.
At Vrushabh Engineering, non metallic flat gaskets are made of resilient or pliable materials and metal or non metal composites are incorporated as reinforcement or filler material. The material selected shall be compatible with the fluid and suitable for the pressure-temperature conditions of the service.
Selection of a flat gasket material and gasket thickness suitable for given service application is the responsibility of the user subject to the requirements of any applicable code or government regulation and also by considering the properties of the flat gasket material as well as the intended service application.
Soft Gasket is a term used when referring to a gasket that is easily compressed under a low bolt load. Soft gaskets are used as heat exchanger gaskets, compressor and bonnet valve gaskets and in pipe flange applications etc.
As leading gasket manufacturers and suppliers Vrushabh Engineering. offers varieties of cut shape / gasket material in sheets / rolls out of the following soft gasket materials:
- PTFE Sheet
- Flexible Graphite Sheet
- Rubber of all grades, Cloth Inserted Rubber & Metal Inserted Rubber Gaskets.
- Ceramic Fiber / Glass Fibre
- PTFE Envelope Gaskets
- Vegetable Fiber Sheet
- Asbestos & Non-Asbestos Sheet
PTFE (Polytetrafluoroethylene) is an inert material with excellent chemical resistance, electrical and thermal insulation. They can be operated in temperatures from cryogenic to 2600°C, offering non-corrosive, non-wetting, non-contaminating and odorless operation. PTFE gaskets by Vrushabh Engineering are mainly used in the presence of aggressive chemicals such as acids, bases and solvents.
Neoprene Gasket used in weather sealing and electrical installation applications possesses good chemical inertia and is appreciated for non-marking, high abrasion resistance, ozone and oil resistant, flame resistance and weather aging characteristics. Gasket materials offered: Neoprene (CR), Nitrile (NBR), Natural Rubber (NR), EPDM etc.
Compressed Non Asbestos Fiber Gaskets are circle cut or die cut gaskets from compressed non asbestos jointing, manufactured from carefully picked fiber intimately blended with suitable heat resistant binders and vulcanized into sheets of homogenous compositions and uniform thickness.
Non-Asbestos Jointing Sheets are made of special non-asbestos heat-resisting fiber, heat-resisting packing material and special rubber compound by heating and compression moulded it. These are used in high temperature and high pressure gasket applications like equipments involving saturated vapour, super hot vapour, gas, air, ammonia alkali, and inert gases and other mediums and used as sealing material in the joints of pipeline. Vrushabh Engineering offers Type AF 111, 120, 139, 154, 159, 160 in the compressed non asbestos fiber types.
Extensively manufactured at Vrushabh Engineering. using quality tested rubber are Nitrile Rubber Gaskets perfect for use with oils, fats, fuels, and other liquids infected by these and are utilized at a range of temperatures ( – 400°C to + 1200°C depending on grade). The gaskets are appreciated for outstanding resistance to petroleum products as well as compression set, tear and abrasion resistance.
laminated gasket with a metal core, covered using soft conformable sealing materials on each face of the core is a Metal Reinforced Gasket falling in the range of up to pressure class 300. The solid metal core prevents gasket blowout by providing high strength and rigidity while the soft core accounts for exceptional gasket sealing.
Metal reinforced gasket manufactured at Vrushabh Engineering finds its application in chemical and petroleum industries being a high temperature gasket, offering corrosion resistance and high integral jointing.
The metal core material possessing chemical resistance and temperature stability is selected to suit the media to be sealed which is either 304 or 316L Stainless Steel with standard core thickness of 1/8”. Soft gasket facings have flexible graphite as their standard material.
Following are a list of gasket materials offered by Vrushabh Engineering for metal reinforced gaskets:
Metallic core materials:
- Stainless Steel Types 316L, 304, 309, 310, 317L, 321, 347, and 430.
- Inconel 600, 625, X -750.
- Incoloy 800, 825.
- Hastelloy B2, C276.
- Monel, CS, Aluminum, Copper, Brass, Titanium, Nickel 200, Alloy 20, Duplex etc.
Soft facing materials:
- Flexible graphite.
- Compressed Fiber.
- PTFE
- Soft metals etc.
Metal reinforced gaskets can be utilized as a part of conventional compressed fiber gasket sheets or in some cases as spiral wound gaskets.
But its main usage rests on special type assemblies and due to the laser manufacturing techniques at Vrushabh Engineering we offer metal reinforced gasket of any desired shape.
Metal reinforced gaskets also finds its usage in restricted or limited space applications, limited bolt load situations in seating the gasket.
Vrushabh Engineering’s metal reinforced gasket has a narrow cross sectional width putting it into usage for floating head arrangements of heat exchangers, earning the usage as heat exchanger gaskets.
Tanged graphite gaskets range of graphite sheet sealing materials are manufactured from highly pure exfoliated graphite flake, with/without a reinforcing metallic core with the standard product offering graphite with a carbon content of 98% whiles for nuclear purposes its 99.85%.
Tanged graphite gasket laminates by Vrushabh Engineering are suitable for moderately high temperature/high pressure gasket applications with a wide range of media. Using mechanical means or certain adhesives, graphite foils can be attached to the reinforcing core.
These gaskets are used in demanding industries such as petrochemical/refining industries as a result of absence of any rubber or polymeric binders making their stress retention levels high. This in turn ensures that the gasket stress applied upon assembly is retained during service.
In chemical service industry, though graphite based products are resistant to most chemicals it is highly imperative to consider any possible reaction between chemical medium and reinforcing metallic core as graphite is susceptible to attack by nitric acid or sulfuric acid at certain concentrations and temperature.
Based on the temperature and concentration of oxygen present and the purity of graphite it may burn away getting converted to oxides of carbon. With a well bolted flange graphite burns away very slowly in contact with the oxygen from the inner edges of the pipes. Whereas, high temperature gasket applications of fluids sealed with no oxygen is influenced by the attack on graphite from the oxygen in the atmosphere surrounding the flange.
Due to the complexity surrounding the oxygen and temperature for graphite getting burnt away the Tightness Testing Research Laboratory [TTRL] on behalf of Pressure Vessel Research Council [PVRC] has recorded maximum service.
Offering versatility and convenience in the form of a highly conformable flexible strip is the expanded PTFE gaskets by Vrushabh Engineering that is used in non-standard flange applications. It is also a backup sealing option under non availability of conventional gaskets.
We at Vrushabh Engineering offer PTFE gaskets with excellent chemical resistance and inherent cleanliness making the product a suitable sealing agent against aggressive media or feedstock contaminated areas. The presence of an adhesive backed strip eases the installation in large or complex flange applications, such as air conveying and solvent recovery systems
Expanded PTFE gaskets are suitable for temperatures ranging up to 5000°F and for cryogenic applications like hydraulic systems, water supply systems, ventilation ducts, fan housing, fume ducts, pneumatic systems, engine case doors etc.
