Slip-On Flange

Specialists in MS Flanges, Custom flanges, etc. E S Haji & Co follows stringent quality control measures which is subjected to inspection by accredited inspection agencies before dispatch and always aims at acquiring customer satisfaction by providing uncompromising standards coupled with prompt schedule to their clientele.

In this Blog E S Haji & Co renders the reason as to why Slip-On Flange is the most common type in the flange industry and enhances the purposes it serves in the industrial sector.


The slip on flanges are slipped over the pipe then welded both inside and outside to provide sufficient strength and prevent leakage.  The pipe end has been cut square. The flange bolt holes are aligned and the flange face squared to the pipe. Then a fillet weld is run around the end of the pipe to fuse it to the inside of the bore of the flange. Another fillet weld is run around the back end of the flange hub fusing it to the outside of the pipe. This is the most common welding flange. Before the final fillet welds are made, temporary tack welds are made until alignment is assured. These tacks are easy to cut out so a correction can be made.There are socket-type slip-on flanges where only the outside weld is made. The squared pipe end butts against a lip inside the flange bore.

Slip-On flanges are commonly lower in price than weld-neck flanges, and to this effect are a popular choice for our customers. However, customers should bear in mind that this initial cost saving may be diminished by the additional cost of the two fillet welds required for proper installation. Moreover, weld-neck flanges have a higher life expectancy than slip-on flanges under duress.

When do you use a Slip-On Flange ?

Slip-On Flanges are probably the most common type of flanges in the industry and are ideal for lower pressure applications. You do not have to specify the pipe schedule when using slip-on flanges due to the fact that its inside diameter is determined by the outside diameter of the pipe. This outside diameter of the pipe does not change for the different schedules.  This often makes these easier to stock for vendors. Fabricators also like the fact that these flanges are slightly easier to align than weld neck flanges. They also are slightly easier to cut pipe to the proper length.

These slip on flanges are used in preference to weld necks by many users because of its lower cost and the fact that less accuracy is required when cutting pipe to length.

They can be used for high temperature and pressure applications but are not generally recommended as compared to other types of flanges. ASME B16.5 Code limits their usage in the 1500#-2500# (lbs.) weight classes. E S Haji & Co offers these flanges in stainless steel and carbon steel material. 

Key Features

Most commonly stocked flange due to the fact that one size fits all pipe schedules.

Fabricators can more easily cut pipe to length for slip-on flanges and their smaller thickness allows for easier alignment of bolting holes

ASME B16.5 code limits their usage for 1500#-2500# (lbs.) applications and they are generally not preferred for high pressure temperature environments.



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