How To Weld A Flange On Pipe

According to ASME B311 to execute a flanged connection using a socket weld flange the pipe shall be at first inserted in the socket of the flange until it reaches the bottom of the flange then it should be lifted by 16 mm and finally welded. The diameter of the slip-on flange is larger than the outer diameter of the pipe on which it is fitted.

Fit Up Jig For Tacking Slip On Flanges I Made At Work Welding Projects Shed Projects

On a socket weld its 116 and can be established with a special spring.

How to weld a flange on pipe. Fillet welding is done from outside on the pipe. Then we weld the outside of the flange to the pipe Tig root 18 ER70s2 and cover w 7018. The connection with the pipe is done with 2 fillet welds as well at the outside as also at the inside of the flange.

Socket-Welded Flanges can be FF or RF. Currently we recess the pipe about 18 to 14 in from the face of the flange and Tig weld the inside w 18 ER70s2. This space is necessary to do not damage the flange face during the welding process.

These flanges are also knows as ANSI Flange or ASME B165 Flange. The connection with the pipe is done with 1 fillet weld at the outside of the flange. Socket-Weld Flanges has a female socket in which the pipe is fitted.

A weldneck flange tapers to the thickness of the pipe wall and then in welded directly to the end of the pipe in a single weld. Posted in Pipe Flange When welding a flange fitting or a piece of pipe together the gap spacing for welding them is established by the Welding Qualification. Generally it is used in small bore piping and only suitable for low pressure and temperature application.

Pipe is welded to socket weld flanges by inserting the pipe into the socket and backing the piping out between 116 and 18. The hole alignment is independent from the welding process and this means welders cant distort the face of the flange with hisher work. One fillet weld is executed on the inside and another on the outside of the flange cavity.

Welding Neck This flange again places the weld in an area away from the flange face and offers more strength against pressure and heat. Our maintenance department wants to weld a ASTM A105 class 150 welded neck flange std to a ½ dia A53 schedule 80 pipe. However I have not found solid reference for joining a fitting to greater wall thickness.

This is to prevent the expanding pipe on the inner side of the weld from expanding when headed and cracking the weld on the fitting. It is not recommended for high-pressure applications. These Flanges are welded only on outside of the Pipe.

I have found sound technical reference for joining butt-welding fittings to pipe of equal or lesser wall thickness. Wall thickness of pipe 3 mm. Installation is slightly more technical as youll need fillet weld both sides to secure the flange to the pipe.

See picture on the right. The flanges are then fastened in place by two fillet welds. The X measure on the image are approximately.

They are usually used in small bore piping where the piping specification is socket weld. API Std 1104 Standard for Welding of Pipelines and Related Facilities calls for a 116 space. METHODS OF WELDING FLANGES TO PIPE The methods used in welding flanges to pipe will vary according to the type of flange and are basically the same as those used in standard welding practices.

They are not used in severe services due to stagnation of fluid at the socket. For welding Neck and Lap Joint Stub and Flange applications an initial root gap spacing between pipe and flange should be 116 to 18. This is the most commonly used flange for.

ASME B311 Preparation for Welding E Socket Weld Assembly saysIn assembly of the joint before welding the pipe or tube shall be inserted into the socket to the maximum depth and then withdrawn approximately 116 16 mm away from contact between the end of the pipe. Both the inside and outside of the pipe is welded on the slip on flange. Socket welded flanges shall be specified with connection pipe thickness to ensure proper bore dimensions.

The pipe is generally inserted all the way inside the slip on flange leaving only the gap equivalent to wall thickness of pipe. Simply match the flange to the outer diameter of the pipe you intend to connect. In assembly of the joint before welding the pipe or tube shall be inserted into the socket to the maximum depth.

The cost of flange and fabrication is moderate. ASME B311 1998 1273 Preparation for Welding E Socket Weld Assembly says.

B16 5 Welding Neck Flanges Dimensions 900 Lbs Dimensions Welding Neck