Stainless Steel Flanges for piping connection

 

Stainless Steel Flanges

Used for piping connection in corrosion conditions.

In addition to being durable and resilient, different grades of stainless steel flanges have varying mechanical properties as well as corrosion resistance. For instance, Austenitic grade has higher ductility, which is why forming a SORF type is relatively easy. Moreover, the machinability properties of austenitic grades are much higher in comparison to the other classes. Not forgetting their excellent resistance to corrosion along with high mechanical properties. On the other hand, the socket weld flange produced from Ferritic Stainless Steel, not only have a higher degree of toughness and hardness, but these flanges are also magnetic. Hence, Ferritic Stainless Steel are applicable in those sectors which have the need for magnetic properties. Usually made in either raised face or flat face, ring joint type are also a common type of flange face produced by most manufacturers.

Typically the ANSI/ ASME B16.5 pipe flange are available in the following size ranges i.e. - ½ inch to 48 inches or 15 NB - 1200NB or between DN10 ~ DN5000. While most manufacturers use ANSI/ASME  B16.47 Series A & B, or B16.5 or B16.48 dimensions to produce threaded flanges. The pressure ratings for BLRF can be produced in any one of the corresponding classes i.e. Class 150 LBS, Class 300 LBS, Class 600 LBS, Class 900 LBS, Class 1500 LBS and Class 2500 LBS.

ASTM A182 Flanges Specification

Grade ASTM A182 F304, F304L, ASTM A182 F316/ F316L, A182 F321
Dimensions 1/2'' to 2'', 6'' and up to 48''.
Wall thickness SCH 10S, SCH 40S, SCH STD, SCH 80S
Pressure Class Class 150, 300, 600, 900, 1500, 2500
Standards
  • ASME / ANSI / ASA B16.5
  • ASME / ANSI / ASA B16.34 (welding/ threaded end)
  • ASME / ANSI / ASA B16.47 Large Dia.

SS Flange connection types and standards

Weld Neck Flange (WNRF)

SS 304 Weld Neck

Socket Weld Flange

321 Socket Weld

Lap Joint Flange

ASTM A182 Grade F304L Lap Joint

Threaded Flange

EN 1092-1 SS Threaded Flange

Slip On Flange (SORF)

A182 F316 Slip On

Blind Flange (BLRF)

ASME SA 182 Gr F316L BLRF

Flange Types

Advantages and disadvantages

Advantages & Benefits

  • Blasting & Painting are not needed
  • Without welding you can assemble Piping spools
  • Various varities in piping spools as required

Disadvantages

  • More expensive to insulate pipe flange
  • Require more space for flanged piping system
  • Flange connection can cause leak possibilities
  • Not advisable for underground piping connection

Melting Point

Melting Point

Tolerance

Threaded Flange

Chemical Composition Chart

Grade/ Marked Symbol Carbon (Max) Manganese (max) Silicon (maximum) Phosphorus (max) Sulfur (max) Chromium Molybdenum Nickel N
F304 0.08 2 0.75 0.045 0.030 18 - 20 - 8 - 11 -
F304L 0.035 2 1.0 0.045 0.030 18 - 20 - 8 - 13 -
F316 0.08 2 1.0 0.045 0.030 16.00 - 18.00 2.00 - 3.00 11.00 - 14.00 67.845 min
F316L 0.035 2 1.00 0.045 0.030 16.00 - 18.00 2.00 - 3.00 10.00 - 14.00 68.89 min

Mechanical Properties Analysis

Grade/ Marked Symbol Density Melting Range Tensile Stress Yield Stress (0.2%Offset) Elongation
F304 8.0 g/cm3 1400 °C (2550 °F) 75000 Psi, 515MPa 30000 Psi, 205 MPa 35 %
F304L 8.0 g/cm3 1400 °C (2550 °F) 75000 Psi, 515MPa 30000 Psi, 205 MPa 35 %
F316 8.0 g/cm3 1400 °C (2550 °F) 75000 Psi, 515MPa 30000 Psi, 205 MPa 35 %
F316L 8.0 g/cm3 1399 °C (2550 °F) 75000Psi, 515MPa 30000 Psi, 205 MPa 35 %

Equivalent Grades Guidelines

STANDARD WNR. UNS Designation Japanese Industrial Standards (JIS) British Standards GOST- Russian National Standards AFNOR (French Standard) European Standards (EN)
Grade 304 1.4301 S30400 SUS 304 BS 304S31 08Х18Н10 Z7CN18‐09 X5CrNi18-10
Grade 304L 1.4306 / 1.4307 S30403 SUS 304L BS 3304S11 03Х18Н11 Z3CN18‐10 X2CrNi18-9 / X2CrNi19-11
Grade 316 1.4401 / 1.4436 S31600 SUS 316 BS 316S31 / 316S33 - Z7CND17‐11‐02 X5CrNiMo17-12-2 / X3CrNiMo17-13-3
Grade 316L 1.4404 / 1.4435 S31603 SUS 316L BS 316S11 / 316S13 03Ch17N14M3 / 03Ch17N14M2 Z3CND17‐11‐02 / Z3CND18‐14‐03 X2CrNiMo17-12-2 / X2CrNiMo18-14-3
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