ASTM A105 & A350 LF2 Carbon Steel Pipe Flanges
Dinesh Tube India is a supplier and exporter of carbon steel flanges in Mumbai, serving EPC contractors, refineries, power plants, process plants and fabricators in India and abroad. We supply forged flanges in ASTM A105 for general and high-temperature piping and ASTM A350 LF2 for low-temperature service.
Flanges are available as weld neck, slip-on, blind, socket weld, threaded, lap joint and RTJ, from 1/2" to 48", Class 150 to 2500, to ASME B16.5 and B16.47, with an EN 10204 3.1 mill test certificate. Send us your flange type, size, class, face, bore schedule and quantity for a quote.
What Are Carbon Steel Flanges?
Carbon steel flanges join pipes, valves, pumps and equipment with a bolted, gasketed joint that can be taken apart for maintenance. Most are forged to ASTM A105 and machined to the dimensions of ASME B16.5 (1/2" to 24") or B16.47 (26" to 60"), so flanges from different makers bolt together.
The flange grade is matched to the pipe: A105 flanges go with A106 Gr B pipe and A234 WPB fittings; A350 LF2 flanges go with A333 Gr 6 pipe and A420 WPL6 fittings in low-temperature piping.
Carbon Steel Flange Grades
For low-temperature flanges, see A350 LF2 flanges and A350 LTCS flanges.
ASTM A105 Chemical Composition & Properties
Values in weight %. Full data on our ASTM A105 flanges page.
Need CS flanges for a project? Send your flange list (type, size, class, face, bore and quantity) to kamlesh@dineshtube-india.com or call +91 83559 10913. You can also send an enquiry.
Types of Carbon Steel Flanges
Weld Neck Flanges
Slip-On Flanges
Blind Flanges
Socket Weld Flanges
Threaded Flanges
RTJ Flanges
A105 Flange Pressure Classes (ASME B16.5)
Material Group 1.1 (A105) ratings at −29 to 38 °C. Allowable pressure falls as temperature rises; check ASME B16.5 tables for your design temperature.
Carbon Steel Flange Applications
Complete your piping package with carbon steel seamless pipes and carbon steel pipe fittings. See all carbon steel products.
Carbon Steel Flanges: FAQs
What material are carbon steel flanges made from?
Most carbon steel flanges are forged to ASTM A105, the standard grade for flanges in ambient and high-temperature piping. For low-temperature service, ASTM A350 LF2 is used because it is impact tested at −46 °C. High-yield pipeline flanges are made to ASTM A694 (F42 to F70) to match API 5L X-grade pipe.
What is the difference between ASTM A105 and A350 LF2 flanges?
Both are forged carbon steel with similar strength. A105 is for ambient and elevated temperatures and is not impact tested as standard. A350 LF2 is made for low-temperature service and must pass a Charpy impact test at −46 °C (Class 1), so it is used with A333 Gr 6 pipe and A420 WPL6 fittings.
Which flange type should I use: weld neck or slip-on?
Weld neck flanges have a long tapered hub that is butt-welded to the pipe, giving the best strength and fatigue resistance; they are used for high pressure, high temperature and cyclic service. Slip-on flanges slide over the pipe and are fillet-welded, so they are cheaper and easier to align, but are normally limited to lower-pressure, less severe service.
What do flange pressure classes 150, 300 and 600 mean?
The class is a pressure-temperature rating under ASME B16.5. For A105 flanges at ambient temperature, Class 150 is rated about 19.6 bar, Class 300 about 51.1 bar and Class 600 about 102 bar. The allowed pressure falls as temperature rises, so the class is chosen from the design pressure and temperature together.
What is the difference between RF, FF and RTJ flange faces?
Raised face (RF) has a small raised ring for the gasket and is the most common. Flat face (FF) is used against cast iron or non-metallic flanges to avoid cracking them. Ring type joint (RTJ) has a groove for a metal ring gasket and is used for high-pressure, high-temperature service, usually Class 600 and above.
Do you supply carbon steel flanges to DIN and EN standards?
Yes. Besides ASME B16.5 and B16.47, we supply carbon steel flanges to EN 1092-1 (PN6 to PN64), DIN and BS 4504 on request, in matching material grades such as P250GH. Send your standard, type, size, pressure rating and face for a quote.
Export Destinations for Carbon Steel Flanges
We export carbon steel flanges from India to the Middle East (UAE, Saudi Arabia, Qatar, Kuwait, Oman, Bahrain, Iraq, Jordan), Africa (Nigeria, Egypt, South Africa, Kenya, Ghana, Algeria, Morocco, Tunisia), Asia (Japan, South Korea, Singapore, Malaysia, Indonesia, Thailand, Vietnam, Philippines, Bangladesh, Sri Lanka), Europe (Italy, Spain, Portugal, France, Netherlands, Belgium, Poland, Romania, Turkey, United Kingdom), and the Americas (United States, Canada, Mexico, Brazil, Chile, Peru, Colombia, Argentina).