The ‘AX’ Gasket Type of Ring Joint Gasket
Among all types of ring joint gaskets, type AX Gasket is specifically designed for offshore drilling manufacturing systems. It has specific features and applications, and it suits subsea and wellhead equipment such as Blow out Preventers (BOP). The AX-type RTJ gasket is commonly manufactured following the original equipment manufacturers’ design and manufacturing process.
Throughout the world, wherever a deep-sea exploration or oil and gas production takes place, the AX type of ring joint gasket is a must component to be added.
Description
The AX Gasket is a special ring joint gasket manufactured by forging, heat treatment, and machining. It is octagonal in shape and used in offshore drilling manufacturing systems.
It has a tight-sealing performance that includes type VX and type CX ring gaskets. The style AX ring joint gaskets are light weighted, and ideal hardness should be 15-20HB lower than the mating flange surface. For an effective seal, both the gasket and the mating surface should be free of scratches, knock-marks, cracks, and other faults, and its surface roughness should not exceed 0.8.
Materials
These gaskets are typically made of stainless steel, and they include a range of different kinds of metal, namely: Soft Iron, Low Carbon Steel, SS410, SS304, SS316(L), SS347, F5, Copper, Aluminum, Inconel 800, 625, 600,825, Monel 400, Titanium, Nickel 20, Hastelloy C276, B3, Zoronium 702, etc.
The AX Gaskets are standardly subjected to silver plating as the coat, and it provides excellent dry film lubrication that lasts long, long term corrosion prevention, metal to metal seal, and the ability to pack out of microscopic irregularities and defects on the gasket seat due to the softness and malleability of silver.
Application of AX Gasket
Just like all other gaskets, type AX is also manufactured to serve certain specific purposes. These gaskets are generally used in the oil and petrochemical, and offshore industries, where deep-sea explorations and productions are done under highly pressurized conditions. The specialty of the AX type is that they can be applied on valves, pipe-work assemblies, and vessel joints, where flanges are subjected to high pressure and high temperature. As they are pressure-energized, AX ring joint gaskets perform their best at high pressure.
As these gaskets are coated ‘in-house’, they provide excellent sealing consistently. The most important fact to remember when using the type AX is that each and every single gasket is manufactured with a unique product stamping to offer full identification and traceability to the customers.
The application, removal, and replacement of the AX RTJ gasket are typically done using a piece of equipment called the AX/VX Gasket Tool. They are used on both AX and VX style gaskets inside the wellhead hub. It acts as a bore and sits flush with the top of the gasket where it is energized with ROV hydraulics. To compensate for a situation where the ROV hydraulic power is interrupted, two compression springs are employed to keep the tool engaged.
Standards
The AX-type ring joint gaskets are manufactured in both standard and non-standard sizes. This includes API 6A, API 17D, ASME B16.20, DIN 2693-67, JPI-7S-23-72, and other standards. In fact, the customers can often get their AX gaskets manufactured or crafted according to the purpose and the condition of the devices and machinery that they will be applied on.
