FLANGES AND ITS DETAILS

                                            

FLANGES

·         Flanges are one of the main connecting part which connects pump, pressure relief valve, ball valve, instruments, pump, motor etc. into the piping skid.

·         Flange is used to avoid permanent joint in the piping system.

·         In piping system two mating flanges make a joint to ease of inspection or cleaning of piping.

·         Two flanges are connected with each other by means of bolting.

·         There are various types of flanges as below

Regular uses flanges in oil and gas, petrochemical etc. industries.

·         SORF: Slip on rest facing flange

·         BLRF: Blind rest face flange

·         WNRF: Weld neck rest face flange

·         SWRF: Socket weld rest face flange

·         LJRF: Lap joint rest face flange

Special purpose flanges

·         Reducing flange

·         Weld neck flange with long neck

·         Expander flange

·         Weldo flange

·         Orifice flange

·         Threaded flanges

 

NOMENCLATURE OF FLANGES

·         ASME B16.5: ASME B16.5 SORF 40 NB 150 #

·         DIN: SORF 40 NB PN16

 

DIMENSIONAL ANALYSIS OF FLANGES

·         Flanges are design on the basis of pressure and temperature rating of the system.

·         Standard dimensional system of flanges are ASME B16.5 and DIN.

·         Flanges are selected for specified piping is as per pipe nominal bore and its pressure rating is on the basis of operating pressure of the system.

·         Flange pressure rating is denoted by its class and its symbol is #.

·         As the class of flange is increases the pressure sustain capacity of flanges are increases.

·         There are various classes in flanges like 150, 300, 600 etc. in ASME and PN6, PN10, PN16 etc. in DIN.

MATERIALS OF FLANGES

·         Flanges are available in various material like Carbon steel/ mild steel, stainless steel, aluminum, brass, bronze etc.

·         Flanges are may be plate cut of IS 2062 that is MS.

·         Stainless steel: ASTM 182 F304, 316 etc.

·         Carbon steel: ASTM A105, A694, A350 etc.

·         Alloy steel: ASTM A182 F1, F5, F9 etc.

 

INSPECTION OF FLANGES

·         Flanges should be visually acceptable.

·         Identification of flanges should be in proper format and same should be mentioned in supplier inspection report and material test certificates.

·         In identification marking supplier should mention following parameters,

·         Make that is manufacturer of flanges, Material grade, Flange size and pressure rating, its standard etc.

·         After visual inspection of flanges needs to check its dimensions as per required standard.

·         In dimensional analysis following parameters are checked.

·         Outer diameter, Inner diameter, pitch circle diameter, thickness, rest face height etc.

·         After dimensional inspection supplier reports and material test certificates should be verify as per standard.