The Gaskets are a sealing agent positioned between the connecting flanges to create a permanent seal that maintains the leakage evidence sealed under all operating conditions. Various types of gaskets were used to attain leak-proof sealing between the flange of the pipe. The main function of the gaskets is to hose each side of the flange irregularities so that the provider liquid will not flow into the flange joint. A gasket tries to fill the flange faces with microscopic spaces and irregularities and then forms a clamp designed to preserve fluids and gasses. A leak-free flange connection is required for the correct installation of damage-free gaskets and damage-free flange faces.
Types of Flange Gaskets
The Piping processes use three different types of Flange Gaskets that are classified based on the nature of their material.
NON-METALLIC GASKETS are generally composite sheet materials used in low-pressure class applications with flat-faced and raised-faced flanges. Made of arid yarn, fiberglass, elastomer, Teflon ® (PTFE), graphite, etc. are some of the materials that are used for the manufacturing of the Non-metallic Gaskets.
The COMPOSITE GASKETS are a combination of both Metallic and non-metallic flanges. They are also referred to as Semi-Metallic Flanges. The metallic property of these gaskets helps them have higher strength and resilience. The Non-metallic properties help them to have the ability to seal and conform to the Flanges.
METALLIC GASKETS are made from one or a mixture of metals to the shape and scale required. Metallic gaskets often used are ring-type connected (RTJ) gaskets.
The Installation Process of the Flange Gaskets
To begin with, make sure that the matting surfaces, especially when working with cast iron flanges, come together evenly and plumb as you fit the pipe and flange. If on the one side the flanges have a big difference over the other, the design has to be changed to make it even better. Excessive friction on the pipe can result in unequal pounds of pressure, excessive joint pain, potential leakages, and split or fractured flanges when twisting the bolts to connect.
The bolt holes are lined up once the proper gasket is in operation, and the flanges have standard distance width which holds the flanges together. Fasten the flange and “two-hole” into your gasket, making sure that through two bolt holes you get at least two bolts. This will encourage you to fine-tune the orientation of the bolt holes for the remainder. When you find the gaps in the line-up hard to get, buy a spud wrench.
On one hand, the spud wrench has a hard mark that you force into the openings and move around the offset bolt before they line up the flange to “door.” Beware of lubricating and adjusting the bolts before moving. Most of the gaskets don’t need any lubrication, despite popular belief. Some manufacturers ‘ instructions say gaskets should be dry, with no lubrication, fresh from storage, and dry assembled at room temperature. The gasket is sealed by even friction and doesn’t need any valve, anti-seize or oil lubrication.
The bolts should be adjusted to the minimum torque level by the supplier, so you’ll need a torque wrench. Tighten the bolts in a diametrically opposite direction (star pattern) until the proper torque has been achieved on all bolts. Many pipe fitters and old-timers swear by “stud bolts” as to the bolts themselves. Stud bolts are a piece of all-thread used instead of a hex-head bolt. It is an all-thread piece cut to length with nuts on both sides.
Finally, the question of creep and relaxation. To ensure that nothing leaks, you must torque the bolts properly and cycle the system, re-evaluate and tighten again if necessary.
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