What is orifice plate?

Orifice plates are one of the most popular devices along with flow meters and flow transmitters for measuring and controlling fluid flow. The shape and manufacturing tolerances of plates used in measuring applications are defined in the international standardization publications of ISO, AGA, ASME, etc.

Petro Parda company as a manufacturer of flow measuring equipment including the following items and based on relevant standards accepts orders from all over the world in this regard.

• Orifice plate

• Restriction orifice plate

• Orifice flange

• Multi stage orifice plate

• Venturi tubes

Orifice plate types

Square Edge Hole (Standard)

For concentric orifices, square edge, hole, and chamfer is the standard method of limiting the plate edge thickness. Unless otherwise specified, the plates are chamfered in accordance with currently accepted standards.

Quarter Edge Hole

A quarter edge hole is an orifice with a rounded inlet edge. Instead of being chamfered, the plate conforms to the desired edge thickness. The radius of the quarter-circle orifice is a function of the orifice to tube ratio (d / D). The thickness at the throat is equal to the radius. This orifice is especially designed for viscous fluids such as heavy crudes, saps and slurries with Reynolds numbers below 100,000.

Eccentric orifice

Orifice plates with an eccentric orifice are plates with an orifice located off-center from the plate. The eccentric orifice is typically cut into a circle that is 98% of the tube diameter, allowing solids or slurries to pass through. Eccentric orifice plates are used in many industries including heavy and light chemicals, steel, paper, and petrochemicals.

Segmental orifice

Segmental orifice plates are provided for measurement where solids are entrained in a gas or liquid stream. The circular section of the hole is cut into a circle, typically 98% of the pipe diameter. The cross-sectional opening may be located at the top or bottom of the pipe. Industries that use these orifices include wastewater treatment, steel, chemicals, water treatment, paper, and petrochemicals.

RTJ Orifice Plate

The RTJ orifice plate has an integral gasket, either an oval or octagonal ring, for installation between ring-type connection flanges. Based on proven technology, it has no moving parts and is suitable for high temperature and pressure applications. Orifice plates are recommended for clean liquids, gases, and low velocity steam flows.

The plate thickness depends on the line size and differential pressure and should be sufficient to prevent the plate from bending under operating conditions. Orifice plates can be manufactured to customer drawings.

Paddle Orifice Plates

Paddle orifice plates are used with RF flanges for metering applications and are installed between ASME standard flanges for restricting applications.

The plate and handle are integrally welded, 1/8 inch thick for line sizes 2 inches through 6 inches and classes less than 900. On all other plates, the handle is welded to the plate as standard. Integral construction is available as an option. The ASME flange class and other standard information are stamped on the handle.

Orifice Plate Materials

RTJ type orifice plates may be machined integrally, or in two pieces, with an orifice plate bolted to a carrier ring/washer.

Standard material grades for orifice plates include 316 stainless steel, 304 stainless steel, 310 stainless steel, Hastelloy® C276, Hastelloy® B3, Duplex, Super Duplex, Monel® 400, Carbon Steel, Titanium, Inconel 800, Inconel 825, Inconel 600 and Inconel 625.

Common carrier ring/washer materials include stainless steel and mild steel. To ensure proper sealing when installed between flanges, the hardness of the carrier ring/washer material is limited to a maximum value, typically 120 for a mild steel ring and 160 for stainless steel.

Difference Between an Orifice Plate and a Restriction Orifice

An orifice plate is used to measure flow, while a restriction orifice is used to reduce pressure upstream of the system, similar to an orifice plate but thicker. While as the fluid passes through the thick plate, energy is lost through friction and heat, resulting in a significant pressure drop.

Restricting Orifice Plate (RO)

A restricting orifice plate is used to manage pressure drop and control flow rate by restricting flow, regardless of downstream conditions. Accurate pressure drop is achieved by accurately calculating the plate orifice, taking into account the entire process.

Multi-stage restrictor orifice plate

This device is used to restrict flow in a pipe or to create a permanent head drop. They can be supplied with flanges, with ends to be welded to the pipe. Also, to achieve the desired pressure drop while avoiding problems such as cavitation, flushing and high levels of noise and vibration, a multi-stage restrictor orifice plate is required. It is economical and cost-effective compared to a regulator or control valve and replaces a valve for a simple, maintenance-free and economical solution.

For any inquiry, send us your requests please. Petro Parda co. manufacture many types of diffrential orifice plates and single / multi stage restriction orifice plates.