Different Finishes You Can Achieve With A Flange Facing

1. Different Finishes You Can Achieve With A Flange Facing With over 130 years in the industry, the American Society of Mechanical Engineers (ASME) is the trend-setter for mechanical engineers in more than 100 countries all across the globe. They are also responsible for deciding the standards for flange face surface finish types through the ASME Standard B 16.5, accredited by ANSI. The standard ensures that all the flange fittings and gaskets are fit and consistent to provide a robust and high-quality seal. In this article, you’ll learn about the standard surface finish types as determined by the industry pioneer ASME.

2. Smooth Finish The flange faces with smooth finish have not even a single sign of tool markings that can be noticed with naked eyes. Most of the time, these finishes are used for gaskets that have metal facings such as flat steel, double jacketed, and corrugated metal. It also resembles the stock finish slightly because it also requires having the contact surface machined with a continuously spinning groove that’s produced by a round-nosed tool of 0.8 mm radius, with a depth of 0.05 mm and a feed rate of 0.3 mm per revolution. Due to this, the roughness lies between Ra 3.2 and 6.3 micrometers.

3. Stock Finish If you’re looking for a finish for flange facings that require being in direct contact with the gasket then the stock finish is certainly a perfect match for you. In this type of finish, the gasket contact surface is prepared using a continuously spinning grove (popularly known as phonographic) that uses a 1.6mm long round-nose tool. It offers a depth of 0.15 mm and provides a feed rate of 0.8 mm per revolution. The resultant finish has a roughness lying between Ra 3.2 and 12.5 micrometers. This type of flange-facing finish is considered to be ideal for a majority of general surface conditions.

4. Spiral Serrated In a way similar to the stock finish, the spiral serrated finish has a continuous spiral groove across the face of the flange. However, unlike the stock finish, it does not include any round-nosed tool. The finish is often found with a groove, generated typically using a 90-degree tool. Due to this, it features a prominent “V” structure with an angle serration of forty-five degrees. Cold Water Finish The surfaces that are equipped with a cold water finish are usually not intended to be used with a gasket at all. In simple terms, this means that the flange faces will be in direct contact with each other. Due to this, the finish is kept equivalent to a ground surface because it has to be used with a wide and high-speed machining tool. The finish is always mirror-like, reflective, and exceptionally smooth with a great overall appearance.

5. Concentric Serrated The concentric serrated finish also uses the same tooling as that of a spiral serrated flange facing finish. However, the grooves that are produced will be centric and kept equally apart from each other, unlike a continuous spiral groove. For this to happen, it is most commonly used with a depth of 0.079 mm and a feed rate of 0.039 mm per revolution.

6. Is Smooth Finish Suitable For Spiral and Non-Metallic Gaskets? While smooth finishflange facings are commonly found in large diameter and low-pressure pipelines, they are primarily used for spiral wounds and solid metal gaskets too. Due to this, they’re usually found on flange joints and machinery instead of pipe flanges. Moreover, when you work with a smooth finish, you need to use a thinner gasket to reduce the effects of cold- and creep-flow. Furthermore, you also need to note that both the smooth finish and thinner gasket require a higher level of compressive force or bolt torque for a perfect seal. The Takeaway So, these were the different finishes that you can achieve with a flange facing. If you read this far, you surely now have a better idea about flange finishes and their types. It’ll surely help you in your professional work a lot.