Types of Orifice Plates

Types of Orifice Plates

The simplest form of orifice plate consists of a thin metal sheet, having in it a square

edged or a sharp edged or round edged circular hole.

There are three types of orifice plates namely

1. Concentric

2. Eccentric and

3. Segmental type.

The concentric type is used for clean fluids. In metering dirty fluids, slurries and fluids

containing solids, eccentric or segmental type is used in such a way that its lower edge coincides

with the inside bottom of the pipe. This allows the solids to flow through without any

obstruction. The orifice plate is inserted into the main pipeline between adjacent flanges, the

outside diameters of the plate being turned to fit within the flange bolts. The flanges are either

screwed or welded to the pipes.

this is copy from papper

i hope it helps

Refer API MMPS 14 Series

Regards

Jose

This question requires books to answer. Anyway, let's provide you with the fundamentals :

You have two main utilizations of orifice plates :

1) Flow restriction. I cannot provide you with details on this one.

2) Flow measurement.

You have two main standards that covers the use of orice plates for measuring fluid flow : AGA3 and ISO5167. These are your supporting documents.

You have basically three types of orifice plate holders :

1) between flanges (like a slice of ham betweens two slices of bread)

The orifice plate in this case is normally called paddle type orfice plate because it as a shape of paddle.

This device will require :

Bypass line and line depressurization to allow plate removal for periodic control and replacement.

A mean to move further apart the two flanges to allow plate removal

2) single chamber orifice fitting. This device will allow you to easily remove/insert the plate as it slides on a plate carrier. It requires line depressurization for plate removal.

3) Double chamber orifice fitting. This device will allow you to easily remove the plate while the line is under pressure and eventually the fluid flowing (under certain conditions).

For 2 and 3, the plates will look like a disk.

You have five basic types of plate bore :

-segmental

-eccentric

-bore and bevel

-bore and counterbor

-quarter-round

These will depend on the application, but to keep it short :

- bore and bevel and quarter round are used under certain reynolds number and limited diameter ratio (Bore Diam/Line ID). Typically for flowmetering.

- The others depend on the type of fluid/viscosity/SG/dirty/multiphase, etc. But I have never been faced to these one and you will hardly find any standards specifying calculation method.

enjoy

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