NOTE: 1. Class 150 flanges except Lap Joint will be furnished with 0.06 (1.6mm) raised face, which is included in ‘Thickness’ (C) and ‘Length through Hub’ (Y1), (Y3). 2. For Slip-on, Threaded, Socket Welding and Lap Joint Flanges, the hubs can be shaped either vertical from base to top or tapered within the limits of 7 degrees. 3. Blind Flanges may be made with the same hub as that used for Slip-on Flanges or without hub. 4. The gasket surface and backside (bearing surface for bolting) are made parallel within 1 degree. To accomplish parallelism, spot facing is carried out according to MSS SP-9, without reducing thickness (C). 5. Depth of Socket (D) is covered by ANSI B 16.5 only in sizes through 3 inch, over 3 inch is at the manufacturer’s option.
What is a slip on flange?
Among the various types of forged flanges, there are some slip types, commonly referred to as slip on flanges. This is a low cost and easy to install flange.
Main characteristics of slip on flange
Slip on flanges are known for their low material costs and ease of installation. Another advantage of these flanges is that they can also be used as lap flanges if type B or type C ends are treated. A variety of diameters and low pressure models are available. Unlike the butt welding flange, this flange has no neck support on the pipe, so it needs to be welded on both sides.
How does the slip on flange work?
Before welding, the flat welding flange must be slid into the pipe. In this case, it is a double welded internal and external, thus providing the durability required to avoid leakage. Their pressure resistance is about 2 / 3 of that of butt welding flange. Slip on flanges are suitable for low pressure applications and are easy to install and weld to different pipes. In addition, welding helps to reduce manufacturing costs. The slip on flange does not need to have large longitudinal space in the pipeline for installation. In addition, they do not require precise cutting in the pipe and are not difficult to align.
Application of slip on flange
They are mainly used for fluids with low pressure or low risk of leakage. Nowadays, it is very common to find these flanges in cooling water pipe line, fire water pipe line, low pressure compressed air pipeline and process pipeline of steam, oil, gas, condensate, etc., but remember that the material to be distributed is low pressure, and the working conditions are not harsh.
Characteristics of slip on flange
Easy to assemble and install.
They occupy the minimum longitudinal space of the flange.
They have a wide range of diameters.
Not recommended for high voltage applications.
Not recommended for use with hazardous liquids or gases.