McMaster-Carr logo
    Forward
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Print
    How can we improve?
    Comments
    E-mail address (if you would like a response)
    20 Products
    About Measuring Fittings
    industrial info icon

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

    Flange-Mount Orifice Valves

    Also known as orifice plates, these mount between orifice flange unions. They are used to throttle, vent, bleed, or regulate the flow of liquids and gases.
    304 Stainless Steel Body
    Image of Product. Front orientation. Orifice Valves. Flange-Mount Orifice Valves.
    For
    Orifice Flange
    Handle
    Orifice
    Dia.
    Water Flow
    Airflow @
    Pressure
    For Flange
    Pipe Size
    For Pipe
    Schedule
    ANSI
    Class
    Surface
    Lg.
    Thk.
    OD
    Ht.
    Wd.
    For Use With
    Max. Pressure
    @ Temp.
    Temp. Range,
    ° F
    Each
    0.412"6.13 gpm @ 40 psi44 scfm @ 40 psi3/4
    		40
    		300
    		Raised7 5/8"1/8"2 5/8"5"1 1/2"Air, Argon, Carbon Dioxide, Helium, Neon, Nitrogen, Oil, Water, Xenon740 psi @ 100° F-20 to 9502206N120000000
     

    Orifice Valves for Water

    Image of Product. Front orientation. Orifice Valves. Orifice Valves for Water.
    Also known as flow restrictors and precision orifice valves, these orifices are used to throttle, vent, bleed, or regulate flow in water systems. They automatically adjust to changing inlet pressure to maintain consistent outlet flow.
    Nickel-Plated Brass Body—Nickel-plated brass orifices are more corrosion resistant than orifices with a plain brass body.
    316 Stainless Steel Body—316 stainless steel orifices have the best corrosion resistance.
    Pipe
    Size
    Lg.
    Max. Pressure
    @ Temp.
    Temp. Range,
    ° F
    Choose an Outlet Water Flow
    Each
    Nickel-Plated Brass Body
     
    NPT Female × NPT Female
    3/42 1/4"200 psi @ 180° F33 to 1801 gpm, 1.5 gpm, 2 gpm, 2.5 gpm, 3 gpm, 4 gpm, 5 gpm, 6 gpm, 7 gpm, 8 gpm, 9 gpm, 10 gpm4762K45000000
     
    316 Stainless Steel Body
     
    NPT Female × NPT Female
    3/42 1/4"200 psi @ 180° F33 to 1801 gpm, 1.5 gpm, 2 gpm, 2.5 gpm, 3 gpm, 4 gpm, 5 gpm, 6 gpm, 7 gpm, 8 gpm, 9 gpm, 10 gpm4762K55000000
     

    Pressure-Compensating Threaded Orifice Valves

    Image of Product. NPT Male × NPT Male. Front orientation. Orifice Valves. Pressure-Compensating Threaded Orifice Valves, NPT Male × NPT Male.
    Image of Product. NPT Female × NPT Female. Front orientation. Orifice Valves. Pressure-Compensating Threaded Orifice Valves, NPT Female × NPT Female.

    NPT Male × NPT

    Male

    NPT Female × NPT

    Female

    When inlet pressure changes, these orifices automatically adjust to deliver a consistent outlet flow. They connect to threaded pipe, or fit into threaded holes. Also known as flow restrictors and precision orifice valves, they are commonly used to regulate the flow of water during treatment.
    Pipe
    Size
    Lg.
    For Use
    With
    Max. Pressure
    @ Temp.
    Temp. Range,
    ° F
    Choose a Water Flow
    Each
    Buna-N Body
     
    NPT Male × NPT Male
    3/4
    		2"Water120 psi @ 140° F40 to 1400.4 gpm @ 120 psi, 0.6 gpm @ 120 psi, 1 gpm @ 120 psi, 1.4 gpm @ 120 psi, 1.8 gpm @ 120 psi, 2.5 gpm @ 120 psi, 3.5 gpm @ 120 psi, 5 gpm @ 120 psi2264N221000000
     
    NPT Female × NPT Female
    3/4
    		2"Water120 psi @ 140° F40 to 1400.7 gpm @ 120 psi, 1 gpm @ 120 psi, 1.4 gpm @ 120 psi, 1.8 gpm @ 120 psi, 2 gpm @ 120 psi, 2.5 gpm @ 120 psi, 3.5 gpm @ 120 psi, 5 gpm @ 120 psi2264N5500000
     

    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.
    Butt Weld × Flanged
    Image of Product. Assembled. Front orientation. Orifice Valves. Flange Unions, Butt-Weld Fitting Connection.
    Image of Product. Exploded. Front orientation. Exploded view. Contains Annotated. Orifice Valves. Flange Unions, Butt-Weld Fitting Connection.

    Assembled

    Exploded

    Butt-weld flanges are also known as weld-neck flanges; the flange neck has a beveled end that, when flush to pipe, creates a trough for a strong weld.
    For 316/316L Stainless Steel Fittings—316/316L stainless steel flanges have excellent corrosion resistance.
    Bolt
    Hole
    Port
    For Carbon
    Steel Fittings
    For 316/316L
    Stainless Steel Fittings
    Pipe
    Size
    Construction
    Flange
    OD
    For Bolt
    Dia.
    Dia.
    No.
    of
    Bolt Circle
    Dia.
    Pipe
    Size
    No.
    of
    Includes
    For Use With
    Temp.
    Pressure
    Class
    For Pipe
    Material
    Each
    For Pipe Material
    Each
    3/4Seamless4 5/8"5/8"11/16"43 1/4"1/2
    		2Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded RodsAir, Natural Gas, Oil, WaterNot Rated300
    		Carbon Steel5291N110000000316/316L Stainless Steel
    		5291N240000000
    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.
    Bolt
    Hole
    Port
    For Carbon
    Steel Fittings
    For 316/316L
    Stainless Steel Fittings
    Pipe
    Size
    Flange
    OD
    For Bolt
    Dia.
    Dia.
    No.
    of
    Bolt Circle
    Dia.
    Pipe
    Size
    No.
    of
    Includes
    For Use With
    Temp.
    Pressure
    Class
    For Pipe
    Material
    Each
    For Pipe Material
    Each
    3/44 5/8"5/8"11/16"43 1/4"1/2
    		2Gaskets, Jack Bolts, Nuts, Port Plugs, Threaded RodsAir, Natural Gas, Oil, WaterNot Rated300
    		Carbon Steel5291N170000000316/316L Stainless Steel
    		5291N310000000

    Orifice Valves for Chemicals

    Made of PVC, these orifices have excellent resistance to a wide range of corrosive chemicals. Also known as flow restrictors and precision orifice valves, they are used to throttle, vent, bleed, or regulate the flow of liquids and gases. They automatically adjust to changing inlet pressure to maintain consistent outlet flow.
    PVC Body
    Image of Product. Front orientation. Orifice Valves. Orifice Valves for Chemicals.
    Lg.
    For Use With
    Max. Pressure
    @ Temp.
    Temp. Range,
    ° F
    Choose an Outlet Water Flow
    Each
    NPT Female × NPT Female
     
    3/4 Pipe Size
    3 1/4"Air, Ammonia, Beverage, Carbon Dioxide, Diesel Fuel, Ethylene Glycol, Food, Hydrochloric Acid, Kerosene, Liquid Carbon Dioxide, Methanol (Methyl Alcohol), Methyl Ethyl Ketone (MEK), Mineral Spirits, Natural Gas, Nitric Acid, Oil, Oxygen, Soap Solutions, Sodium Hydroxide (Caustic Soda), Water120 psi @ 75° F40 to 1403 gpm, 4 gpm, 5 gpm, 6 gpm, 7 gpm, 8 gpm2272N30000000
     

    Threaded Orifice Valves

    Connect these orifices to threaded pipe, or insert them into threaded holes. Also known as flow restrictors and precision orifice valves, they are used to throttle, vent, bleed, or regulate the flow of liquids and gases.
    Brass Body—NPT Male × NPT Female
    Image of Product. Front orientation. Orifice Valves. Threaded Orifice Valves, Female, Male, NPT Thread.
    Water Flow
    Lg.
    For Use
    With
    Max. Pressure
    @ Temp.
    Temp. Range,
    ° F
    Outlet Water
    Flow
    Each
    3/4 Pipe Size
    1 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1801 gpm8105K111000000
    2 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1802 gpm8105K11200000
    3 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1803 gpm8105K11300000
    4 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1804 gpm8105K11400000
    5 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1805 gpm8105K11500000
    6 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1806 gpm8105K11600000
    7 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1807 gpm8105K11700000
    8 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1808 gpm8105K11800000
    9 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 1809 gpm8105K11900000
    10 gpm @ 120 psi1 1/2"Water200 psi @ 180° F33 to 18010 gpm8105K12100000
     
    back to top