Any information is appreciated. Regards Samuel. Its operator's preference. For I'd go with the RTJ myself. Various combinations were also used, i. It also tends to be self-actuating i. Over time, most refiners modified their criteria, reducing the instances in which RTJ flanges were required. For example, it might initially have applied to all Class and greater flanges, then to Class flanges over 12 inch, Class over 6 inch and then to Class We have done this for more than 20 years without any problems.
Prior to making this change, we had used raised face flanges for all Class and lower services for many years, also without issues. Recently some refiners have preferred to use Kammprofile gaskets instead of spiral wound. The change to all raised face flanges was made after observing them perform without incident in Class service.
Many refiners had recommended this change based upon their experiences prior to our making it. Another reason for the change is the potential for crack formation at the intersection of the sides and bottom of the groove in RTJ flanges. These cracks can propagate into the base metal. Ring type joint grooves may also accumulate dirt, moisture, etc when the flange is open, i.
A small amount of damage including corrosion on the narrow sealing surface s may lead to a leak. Another factor is that the grooves and gasket must align properly in order to assemble the flange and obtain a seal. They must stay aligned throughout the operating cycle. The latter point becomes an issue when mating flanges are made of different materials and not providing different hardness materials for flange and ring and also thermal expansion is a concern.
We ask the service staff to always think about the customers, solve the problems of the equipment in time, and make sure that the interests of customers are above everything else. About Us. Technical Data. Contact Us. Related products View more. They are used with metal to metal seals no gasket. The average arithmetic roughness height values are very important during the selection of flanges and gasket materials. Every material possesses a surface roughness and sometimes surfaces are finished deliberately to have a specific roughness small or bigger.
There are various standards for the roughness of surfaces, set according to their type of application. In contact type profilometer the roughness is measured by moving the material under the profilometer stylus. However, modern equipment features non-contact measurements, leveraging the optical and ultrasonic technologies.
The tool used to imprint a rough finish on the flange should have a radius of 0. The groove density on the flange face should be from 45 grooves per inch to 55 grooves per inch 1. These are the standards for semi-metallic and nonmetallic gaskets. If the average roughness of flange face is not according to the described standards, the contacting surfaces would not properly seal and the flanged joint may wear after some time working under pressure resulting in loss of bolt joint tightness and a possible leakage.
The soft nonmetallic materials such as PTFE may be used for more comfortable facing and better creep resistance. According to ASME, the adjacent imperfections should be separated by a distance of at least 4 times the maximum radial projection.
The serrations shall be at the same level, and the protrusion above them is not permitted. It can cause the adjacent serrations to lose hold of the gasket material and may result in wears and leakages. How frequently you update your website? My brother suggested I might like this blog. He was entirely right. This post actually made my day. You can not imagine just how much time I had spent for this information! Simply want to say your article is as astonishing.
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How much of the face of a flat flange should have the grooves? The side wall surface finish of the gasket groove in the flange shall not exceed 1. The RTJ flange is considered to be the most efficient flange used in process piping systems. The ring and groove design actually uses internal pressures to enhance the sealing capacity of the connecting flanges.
Higher the working pressure in the piping system, better the sealing performance. The most obvious disadvantage of a ring type joint is that this configuration is most expensive. The precise control of machining both the metallic ring gasket and the ring-joint groove in the flange is very costly.
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