Socket Welding Forged Flange

People are wondering 300lb Socket Welding Flange with Schedule? As we know that Pipe Fittings have different description of pressure ratings. The pressure ratings of Socket Weld Fittings are 3000, 6000, 9000 that defined as LB or Class. And for Butt Weld Fittings which are Sch40, Sch80 and so on, they are described as Schedule. However, the pressure of Forged Steel Flanges are both. Why flanges have both pressure and Schedule? Let’s show the answer by latest order of 3/4 Inch 300lb Sch80 Forged A105 Socket Weld Flange RF.

ASME B16.5 Socket Weld Flange RF

They are NPS 1/2 to 3 only in class 300. It is more suitable for small diameter pipeline because it is easy to weld. Socket Welding can help to align pipes and strengthen the socket. Carbon Steel Socket Weld Flange should take magnetic detection after welding.

300lb Socket Welding Flange ASME ANSI B16.5

Class 300 is the pressure rating of flange itself. It is determined by the pipe system in which it is located. They are constructed with more metal and can withstand more pressure, so the weight is heavier than Class 150 Flange in same size.

For example, the weight of 3/4 inch 300LBs Socket Weld Flange is 1.11kg, while 150lbs Flange is 0.6, and 600lbs Flange is 1.21. Therefore, we can say the Socket Weld Flanges are in same size, the larger the pressure is, the heavier the weight is.

Besides, Socket Weld Flange can be Class150, Class300, Class600, Class900, Class1500 and Class2500. The description of flange pressure can be 300lb, 300lbs, Class 300, or 300#.

What’s more, the material and temperature influence the pressure it can bear. For the Class 300 Flange, an A105 Socket Weld Flange can withstand pressure 46.6 bar when temperature is 100℃, while an A350 Gr LF1 CL1 Flange, a carbon steel flange as well, can bear 38.8 bar at 100℃.

The relationship between temperature and working pressure as follow.

Temp. ℃,	Working  Pressure by  Class 300, Bar
-29 to 38	51.5
50	50.1
100	46.6
150	45.1
200	43.8
250	41.9
300	39.8
325	38.7
375	36.4
400	34.7
425	28.8
450	23.0
475	17.4
500	11.8
538	5.9

Schedule 80 Raised Face Flange

Sch80 refers to the schedule of 300lb Socket Welding Flange Raised Face. In other word, it is the thickness of sealing face. The schedule should match the schedule of pipe to which flanges are connected.

Raised Face Flange is the most common flange type which suits for all kind of flanges and is easy to identify due to its higher gasket surface. And socket weld flange is available in RTJ (ring type joint) as well.

The schedule could be: Sch20, Sch40, XS, Sch80, Sch100, Sch120, Sch140, Sch160 and XXS.

So Forged 300lb Socket Welding Flange Sch80 uses Class 300 to describe the pressure rating of flange, and uses Sche80 to describe the thickness of sealing face.

Carbon Steel Socket Weld Flanges

The most common carbon steel material for forgings is ASTM A105. A105 Socket Weld Flange is wildly used in ambient and higher temperature service in pressure system.

Normalizing is its heat treatment. Heat treatment is not a mandatory requirement of A105 Flanges except following conditions:

• Flanges above Class 300.
• Special designed Flanges where the design pressure at the design temperature exceeds the pressure-temperature ratings of Class 300.
• Flanges of special design where the design pressure or design temperature are not know.

A350 LF1, LF2 are low temperature Carbon Steel Socket Weld Flange Class 300 for forgings. A350 covers several grades of carbon and low-alloy steel forged or ring-rolled flanges, Forged Fittings and valves intended primarily for low-temperature service and requiring notch toughness testing. LF1 and LF2 are both C–Mn–Si carbon steel.