Orifice Flow Meters | Flozone Measurements LTD

Orifice Plate Flow Meters

Reliable and Cost-Effective Flow Measurement

A widely used and well-accepted gas flow metering technology, orifice plates are proven and standardized throughout the industry. Low cost, simple design, low maintenance and wide temperature ranges are some of the advantages
offered by orifice plates.

The typical accuracy ranges from ±0.5% to ±1.5% when properly installed. Flozone has several sizes and models of orifice plate
flow meters in stock, as well as plates and spare parts shipping from our warehouse. Contact your Flozone Sales Rep or send us a message today
for a quote!

Orifice Fitting Devices

Orifice Fitting & Meters; serve as critical components for positioning the orifice plate within the fluid stream properly. Each manufacturer must conform to strict tolerances to align the concentricity of the plate and plate holder inside the Fitting. End configurations are available in flange by flange, weld by flange, and weld by weld for low- and high-pressure applications. Often Orifice Meters are used in pipeline and hazardous
applications.

These include:

Orifice Flange Union (OFU): This economic option provides accurate measurements but requires depressurization for plate changes. An OFU consists of two flanges that have flange taps machined into them. Ensuring the correct alignment of flange bores and centering the orifice plate within the flange bore is crucial for compliance with AGA tolerances. Additionally, the pipe alignment must also meet these tolerances to maintain measurement accuracy. Care must be taken to prevent flange gaskets from protruding into the bore, as this can distort the flow profile and introduce measurement errors. To facilitate proper alignment, dowel pins are often recommended, and jackscrews are commonly used to separate the flanges for easy orifice plate removal.
Single Chamber Fitting (SC): Another economical choice, simplifying plate changes with a clamping mechanism that eliminates the need for extensive disassembly. However, SC fittings still require blocking in and blowing down the line pressure to check or change an orifice plate. The SC fitting, plate holder is a one-piece body that reduces plate misalignment. Most common sizes are limited to 2" - 8"

Dual Chamber Fitting (DC): A more expensive fitting option, the DC Fitting allows plate changes without depressurizing the line, making it ideal for applications where frequent changes or uninterrupted operation are critical. The DC Fitting is the best choice for applications where minimizing blowdowns is a concern for operators. It features two chambers, allowing the orifice plate to be raised for inspection. This is achieved by using an internal valve inside the fitting to separate the bottom chamber from the top chamber. Following a sequence specified by the manufacturer's operating instructions, the user can easily separate, blow down, and remove the plate while the line remains pressurized.

Double Block and Bleed (DBB) Dual Chamber: The most expensive of all the Fittings due to its design. A specialized design that features two sealing mechanisms, allowing the operator to isolate the upstream and downstream
sides of the meter. This ensures safety during maintenance or plate changes and prevents cross-contamination of fluids due to its venting capabilities between both the middle and upper chambers. DBB systems are particularly
beneficial in high-pressure or hazardous fluid applications.

Types of Orifice Plates

Orifice plates are essential components in metering systems, offering different configurations to suit various applications. The most common types of orifice plates, as referenced in AGA Report #3 and API 14.3, are Universal and Paddle types. Each of
these orifice plate types is manufactured to precise tolerances to ensure compliance with AGA Report #3 and API 14.3 standards. Selecting the appropriate plate type for the application ensures accurate flow measurement and reliable performance.

Orifice plates include:

Concentric Orifice Plate: The most commonly used design for custody transfer features a bore centered in the plate. This design is ideal for clean fluids, such as natural gas and liquids, and provides reliable and accurate measurements when flow conditions are stable. These plates have a square and sharp edge, and meet tight tolerances for finish, flatness, and bore.
Eccentric Orifice Plate: Designed with an off-center bore, this type is suitable for applications where particulates or entrained liquids might accumulate. The eccentric design allows debris to pass through, reducing the risk of clogging.
Segmental Orifice Plate: Featuring a semi-circular bore, this plate is well-suited for measuring slurry or dirty fluids. Its design ensures that heavier particles can flow through without obstruction.
Quadrant Edge Orifice Plate: Typically used for measuring highly viscous fluids, the quadrant edge design minimizes the impact of fluid viscosity on measurement accuracy.

Contact your Flozone Sales Representative today or send us a message for a quote