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    103 Products
    About Pipe and Fittings
    industrial info icon

    Measure your pipe and fittings to identify their pipe size, thread size, schedule, and thread type. Then, find compatible components.

    Low-Pressure Stainless Steel Unthreaded Pipe Flanges

    Bolt two flat-surface flanges or two raised-surface flanges of the same size together with a gasket (sold separately) to create an access point in a pipe line.
    Forged Flanges
    Image of Product. Front. Front orientation. Pipe and Fittings. Low-Pressure Stainless Steel Unthreaded Pipe Flanges, Forged Flanges, Slip-On Weld Female, Raised Surface.

    Front

    Forged flanges have better strength than cast flanges.
    Slip-on-Weld Fitting Connection—Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.
    304/304L Stainless Steel—Flanges hold up in humid, damp, and washdown environments but will corrode if exposed to salt water or chemicals.
    316/316L Stainless Steel—Flanges are the most corrosion resistant. They stand up to wet environments, just like 304 stainless steel flanges, but unlike 304 stainless steel, they will not corrode from salt water, chlorine solutions, and chemicals.
    Pipe
    Size
    Bolt
    Hole
    304/304L
    Stainless Steel
    316/316L
    Stainless Steel
    (A)
    (B)
    Flanged Connection
    Surface (B)
    Flange
    OD
    For Bolt
    Dia.
    Dia.
    No.
    Of
    Bolt Circle
    Dia.
    Pressure
    Class
    Max. Pressure
    @ Temp.
    Max. Steam Pressure
    @ Temp.
    Each
    Each
    Slip-On Weld Female
    1/2
    		1/2
    		Raised3 1/2"1/2"5/8"42 3/8"150
    		230 psi @ 72° F—44685K17800000044695K168000000
    3/4
    		3/4
    		Raised3 7/8"1/2"5/8"42 3/4"150
    		230 psi @ 72° F—44685K1790000044695K16900000
    1
    		1
    		Raised4 1/4"1/2"5/8"43 1/8"150
    		230 psi @ 72° F—44685K1810000044695K17100000
    1
    		1
    		Raised115 mm12 mm14 mm485 mm—230 psi @ 72° F125 psi @ 300° F1442N1100000———0
    1 1/4
    		1 1/4
    		Raised4 5/8"1/2"5/8"43 1/2"150
    		230 psi @ 72° F—44685K1820000044695K17200000
    1 1/2
    		1 1/2
    		Raised5"1/2"5/8"43 7/8"150
    		230 psi @ 72° F—44685K1830000044695K17300000
    2
    		2
    		Raised6"5/8"3/4"44 3/4"150
    		230 psi @ 72° F—44685K1840000044695K17400000
    2
    		2
    		Raised165 mm16 mm18 mm4125 mm—230 psi @ 72° F125 psi @ 300° F1442N12000000———0
    2 1/2
    		2 1/2
    		Raised7"5/8"3/4"45 1/2"150
    		230 psi @ 72° F—44685K18500000044695K175000000
    3
    		3
    		Raised7 1/2"5/8"3/4"46"150
    		230 psi @ 72° F—44685K18600000044695K176000000
    3
    		3
    		Raised200 mm16 mm18 mm8160 mm—230 psi @ 72° F125 psi @ 300° F1442N13000000———0
    3
    		3
    		Raised200 mm16 mm18 mm8160 mm—230 psi @ 72° F145 psi @ 300° F———01458N13000000
    4
    		4
    		Raised9"5/8"3/4"87 1/2"150
    		230 psi @ 72° F—44685K18700000044695K177000000
    4
    		4
    		Raised220 mm16 mm18 mm8180 mm—230 psi @ 72° F125 psi @ 300° F1442N14000000———0
    4
    		4
    		Raised220 mm16 mm18 mm8180 mm—230 psi @ 72° F145 psi @ 300° F———01458N14000000
    6
    		6
    		Raised11"3/4"7/8"89 1/2"150
    		230 psi @ 72° F—44685K18800000044695K178000000
    6
    		6
    		Raised285 mm20 mm22 mm8240 mm—230 psi @ 72° F125 psi @ 300° F1442N15000000———0
    8
    		8
    		Raised13 1/2"3/4"7/8"811 3/4"150
    		230 psi @ 72° F—44685K17300000044695K163000000
    10
    		10
    		Raised16"7/8"1"1214 1/4"150
    		230 psi @ 72° F—44685K32200000044695K251000000
    12
    		12
    		Raised19"7/8"1"1217"150
    		230 psi @ 72° F—44685K32300000044695K252000000
     
    Cast Flanges
    Image of Product. Front. Front orientation. Pipe and Fittings. Low-Pressure Stainless Steel Unthreaded Pipe Flanges, Cast Flanges, Slip-On Weld Female, Flat Surface.

    Front

    Cast flanges are also called MSS flanges.
    Slip-on-Weld Fitting Connection—Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.
    304 Stainless Steel—Flanges hold up in humid, damp, and washdown environments but will corrode if exposed to salt water or chemicals.
    316 Stainless Steel—Flanges are the most corrosion resistant. They stand up to wet environments, just like 304 stainless steel flanges, but unlike 304 stainless steel, they will not corrode from salt water, chlorine solutions, and chemicals.
    Pipe
    Size
    Bolt
    Hole
    304
    Stainless Steel
    316
    Stainless Steel
    (A)
    (B)
    Flanged Connection
    Surface (B)
    Flange
    OD
    For Bolt
    Dia.
    Dia.
    No.
    Of
    Bolt Circle
    Dia.
    Pressure
    Class
    Max. Pressure
    @ Temp.
    Each
    Each
    Slip-On Weld Female
    1/2
    		1/2
    		Flat3 1/2"1/2"5/8"42 3/8"150
    		230 psi @ 72° F43505K34100000043615K551000000
    3/4
    		3/4
    		Flat3 7/8"1/2"5/8"42 3/4"150
    		230 psi @ 72° F43505K3420000043615K55200000
    1
    		1
    		Flat4 1/4"1/2"5/8"43 1/8"150
    		230 psi @ 72° F43505K3430000043615K55300000
    1 1/4
    		1 1/4
    		Flat4 5/8"1/2"5/8"43 1/2"150
    		230 psi @ 72° F43505K3440000043615K55400000
    1 1/2
    		1 1/2
    		Flat5"1/2"5/8"43 7/8"150
    		230 psi @ 72° F43505K3450000043615K555000000
    2
    		2
    		Flat6"5/8"3/4"44 3/4"150
    		230 psi @ 72° F43505K3460000043615K556000000
    2 1/2
    		2 1/2
    		Flat7"5/8"3/4"45 1/2"150
    		230 psi @ 72° F43505K34700000043615K557000000
    3
    		3
    		Flat7 1/2"5/8"3/4"46"150
    		230 psi @ 72° F43505K34800000043615K558000000
     
    Forged Flange Adapters
    Image of Product. Slip-On Front. Front orientation. Pipe and Fittings. Low-Pressure Stainless Steel Unthreaded Pipe Flanges, Forged Flange Adapters, Slip-On Weld Female, Raised Surface.
    Image of Product. Slip-On Raised Surface on Back. Back orientation. Pipe and Fittings. Low-Pressure Stainless Steel Unthreaded Pipe Flanges, Forged Flange Adapters, Slip-On Weld Female, Raised Surface.

    Slip-On Front

    Slip-On

    Raised

    Surface on

    Back

    Forged flanges have better strength than cast flanges.
    Slip-on-Weld Fitting Connection—Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.
    316/316L Stainless Steel—Flanges are the most corrosion resistant. They stand up to wet environments, just like 304 stainless steel flanges, but unlike 304 stainless steel, they will not corrode from salt water, chlorine solutions, and chemicals.
    Pipe
    Size
    Bolt
    Hole
    316/316L
    Stainless Steel
    (A)
    (B)
    Flanged Connection
    Surface (B)
    Flange
    OD, mm
    For Bolt
    Dia., mm
    Dia.,
    mm
    No.
    Of
    Bolt Circle
    Dia., mm
    Max. Pressure
    @ Temp.
    Max. Steam Pressure
    @ Temp.
    Each
    Slip-On Weld Female
    1
    		1
    		Raised1151214485230 psi @ 72° F145 psi @ 300° F1458N110000000
    2
    		2
    		Raised16516184125230 psi @ 72° F145 psi @ 300° F1458N12000000
     
    Forged Reducing Flanges
    Image of ProductInUse. Reducing Flange. Side1 orientation. Contains Annotated. Pipe and Fittings. Low-Pressure Stainless Steel Unthreaded Pipe Flanges, Forged Reducing Flanges, Slip-On Weld Female, Raised Surface.
    Image of Product. Slip-On Front. Front orientation. Pipe and Fittings. Low-Pressure Stainless Steel Unthreaded Pipe Flanges, Forged Reducing Flanges, Slip-On Weld Female, Raised Surface.
    Image of Product. Slip-On Raised Surface on Back. Back orientation. Pipe and Fittings. Low-Pressure Stainless Steel Unthreaded Pipe Flanges, Forged Reducing Flanges, Slip-On Weld Female, Raised Surface.

    Reducing

    Flange

    Slip-On Front

    Slip-On

    Raised

    Surface on

    Back

    Forged flanges have better strength than cast flanges.
    Reducing flanges allow you to transition your system to a smaller pipe size; attach to a flange with a larger pipe size but with the same flange dimensions.
    Slip-on-Weld Fitting Connection—Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.
    304/304L Stainless Steel—Flanges hold up in humid, damp, and washdown environments but will corrode if exposed to salt water or chemicals.
    316/316L Stainless Steel—Flanges are the most corrosion resistant. They stand up to wet environments, just like 304 stainless steel flanges, but unlike 304 stainless steel, they will not corrode from salt water, chlorine solutions, and chemicals.
    Bolt
    Hole
    304/304L
    Stainless Steel
    316/316L
    Stainless Steel
    Pipe Size
    (A)
    For Flange
    Pipe Size (B)
    Flanged Connection
    Surface (B)
    Flange
    OD
    For Bolt
    Dia.
    Dia.
    No.
    Of
    Bolt Circle
    Dia.
    Pressure
    Class
    Max. Pressure
    @ Temp.
    Max. Steam Pressure
    @ Temp.
    Each
    Each
    Slip-On Weld Female
    3/4
    		1
    		Raised4 1/4"1/2"0.62"43 1/8"150
    		230 psi @ 72° F150 psi @ 360° F44685K34400000044695K2720000000
    1
    		—Raised5"1/2"0.62"43 7/8"150
    		230 psi @ 72° F150 psi @ 360° F———044695K273000000
    1
    		1 1/2
    		Raised5"1/2"0.62"43 7/8"150
    		230 psi @ 72° F150 psi @ 360° F44685K34500000———0
    1
    		2
    		Raised6"5/8"3/4"44 3/4"150
    		230 psi @ 72° F150 psi @ 360° F44685K13100000044695K131000000
    1 1/2
    		2
    		Raised6"5/8"3/4"44 3/4"150
    		230 psi @ 72° F150 psi @ 360° F44685K34600000044695K274000000
    2
    		3
    		Raised7 1/2"5/8"3/4"46"150
    		230 psi @ 72° F150 psi @ 360° F44685K13200000044695K132000000
    2
    		4
    		Raised9"5/8"3/4"87"150
    		230 psi @ 72° F150 psi @ 360° F44685K34700000044695K275000000
    3
    		4
    		Raised9"5/8"3/4"87 1/2"150
    		230 psi @ 72° F150 psi @ 360° F44685K13300000044695K133000000
    4
    		6
    		Raised11"3/4"7/8"89 1/2"150
    		230 psi @ 72° F150 psi @ 360° F44685K13400000044695K134000000
    6
    		8
    		Raised13 1/2"3/4"7/8"811 3/4"150
    		230 psi @ 72° F150 psi @ 360° F44685K135000000———0
     

    High-Pressure Stainless Steel Unthreaded Pipe Flanges

    Use these heavy duty forged flanges for high-pressure applications. Bolt two flat-surface flanges or two raised-surface flanges of same size together with a gasket (sold separately) to create an access point in a pipe line.
    Forged Flanges
    Image of Product. Slip-On. Front orientation. Pipe and Fittings. High-Pressure Stainless Steel Unthreaded Pipe Flanges, Forged Flanges, Slip-On Weld Female, Raised Surface.

    Slip-On

    Forged flanges have better strength than cast flanges.
    Slip-on-Weld Fitting Connection—Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.
    304/304L Stainless Steel—Flanges hold up in humid, damp, and washdown environments but will corrode if exposed to salt water or chemicals.
    316/316L Stainless Steel—Flanges are the most corrosion resistant. They stand up to wet environments, just like 304 stainless steel flanges, but unlike 304 stainless steel, they will not corrode from salt water, chlorine solutions, and chemicals.
    Pipe
    Size
    Dash
    Size
    Bolt
    Hole
    304/304L
    Stainless Steel
    316/316L
    Stainless Steel
    (A)
    (B)
    (A)
    (B)
    Flanged Connection
    Surface (B)
    Flange
    OD
    For Bolt
    Dia.
    Dia.
    No.
    Of
    Bolt Circle
    Dia.
    Pressure
    Class
    Max. Pressure
    @ Temp.
    Max. Steam Pressure
    @ Temp.
    Each
    Each
    Slip-On Weld Female
    1/2
    		1/2
    		0808Raised3 3/4"1/2"0.625"42 5/8"300
    		600 psi @ 72° F300 psi @ 360° F4448T2510000004452T261000000
    3/4
    		3/4
    		1212Raised4 5/8"5/8"0.75"43 1/4"300
    		600 psi @ 72° F300 psi @ 360° F4448T252000004452T26200000
    3/4
    		3/4
    		1212Raised4 5/8"5/8"0.75"43 1/4"600
    		1,200 psi @ 72° F840 psi @ 400° F———01503N1200000
    1
    		1
    		1616Raised4 7/8"5/8"0.75"43 1/2"300
    		600 psi @ 72° F300 psi @ 360° F4448T253000004452T26300000
    1
    		1
    		1616Raised4 7/8"5/8"0.75"43 1/2"600
    		1,200 psi @ 72° F840 psi @ 400° F1538N17000001503N1300000
    1 1/4
    		1 1/4
    		2020Raised5 1/4"5/8"0.75"43 7/8"300
    		600 psi @ 72° F300 psi @ 360° F4448T254000004452T264000000
    1 1/2
    		1 1/2
    		2424Raised6 1/8"3/4"0.875"44 1/2"300
    		600 psi @ 72° F300 psi @ 360° F4448T2550000004452T265000000
    1 1/2
    		1 1/2
    		2424Raised6 1/8"3/4"0.875"44 1/2"600
    		1,200 psi @ 72° F840 psi @ 400° F1538N19000000———0
    2
    		2
    		3232Raised6 1/2"5/8"0.75"85"300
    		600 psi @ 72° F300 psi @ 360° F4448T2560000004452T266000000
    2
    		2
    		3232Raised6 1/2"5/8"0.75"85"600
    		1,200 psi @ 72° F840 psi @ 400° F1538N210000001503N16000000
    2 1/2
    		2 1/2
    		4040Raised7 1/2"3/4"0.875"85 7/8"300
    		600 psi @ 72° F300 psi @ 360° F4448T2570000004452T267000000
    3
    		3
    		4848Raised8 1/4"3/4"0.875"86 5/8"300
    		600 psi @ 72° F300 psi @ 360° F4448T2580000004452T268000000
    3
    		3
    		4848Raised8 1/4"3/4"0.88"86 5/8"600
    		1,200 psi @ 72° F840 psi @ 400° F1538N23000000———0
    4
    		4
    		6464Raised10"3/4"0.875"87 7/8"300
    		600 psi @ 72° F300 psi @ 360° F4448T2590000004452T269000000
    4
    		4
    		6464Raised10 3/4"7/8"1"88 1/2"600
    		1,200 psi @ 72° F840 psi @ 400° F1538N24000000———0
    6
    		6
    		9696Raised12 1/2"3/4"0.875"1210 5/8"300
    		600 psi @ 72° F300 psi @ 360° F4448T2610000004452T271000000
    8
    		8
    		——Raised15"7/8"1"1213"300
    		600 psi @ 72° F300 psi @ 360° F4448T43000000———0
     

    Flange Unions

    Measure, throttle, and regulate the flow of liquids and gases in your line by adding an orifice plate to these unions. They consist of two flange halves, plus all of the components needed to connect them together. Tighten the jack bolts to separate the flange halves to inspect or replace the orifice plate.
    To throttle flow, mount an orifice plate between the two flanges. The orifice plate restricts the flow in order to regulate it.
    To measure flow, build the same assembly, except you’ll also connect a differential pressure gauge or transmitter to both flange halves using the threaded ports. Your gauge or transmitter will measure the difference between the pressure before and after the orifice plate. The pressure difference is proportional to flow rate, so you can use that measurement to calculate your line’s flow rate.
    Material Certificate Icon
    Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.
    Slip-On Weld × Flanged
    Image of Product. Assembled. Front orientation. Orifice Valves. Flange Unions, Slip-on-Weld Fitting Connection.
    Image of Product. Exploded. Front orientation. Exploded view. Contains Annotated. Orifice Valves. Flange Unions, Slip-on-Weld Fitting Connection.

    Assembled

    Exploded

    Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.
    For 316/316L Stainless Steel Fittings—316/316L stainless steel flanges have excellent corrosion resistance.
    ASME B16.36—Flanges that meet ASME B16.36 adhere to specifications and testing requirements for temperature and pressure ratings, dimensions, materials, and tolerances.
    Bolt
    Hole
    Port
    For 316/316L
    Stainless Steel Fittings
    Pipe
    Size
    Flange
    OD
    For Bolt
    Dia.
    Dia.
    No.
    of
    Bolt Circle
    Dia.
    Pipe
    Size
    No.
    of
    Includes
    Specs. Met
    For Use With
    Temp.
    Pressure
    Class
    For Pipe Material
    Each
    3/44 5/8"5/8"11/16"43 1/4"1/2
    		2Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded Rods—Air, Natural Gas, Oil, WaterNot Rated300
    		316/316L Stainless Steel
    		5291N310000000
    14 7/8"5/8"11/16"43 1/2"1/2
    		2Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded RodsASME B16.36Air, Natural Gas, Oil, WaterNot Rated300
    		316/316L Stainless Steel
    		5291N32000000
    1 1/26 1/8"3/4"13/16"44 1/2"1/2
    		2Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded RodsASME B16.36Air, Natural Gas, Oil, WaterNot Rated300
    		316/316L Stainless Steel
    		5291N33000000
    26 1/2"5/8"11/16"85"1/2
    		2Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded RodsASME B16.36Air, Natural Gas, Oil, WaterNot Rated300
    		316/316L Stainless Steel
    		5291N34000000
    38 1/4"3/4"13/16"86 9/16"1/2
    		2Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded RodsASME B16.36Air, Natural Gas, Oil, WaterNot Rated300
    		316/316L Stainless Steel
    		5291N3500000000
    410"3/4"13/16"87 7/8"1/2
    		2Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded RodsASME B16.36Air, Natural Gas, Oil, WaterNot Rated300
    		316/316L Stainless Steel
    		5291N3600000000
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