Reducing orifice plate solution theres a new standard in orifice plate design. As shown, the orifice is equidistant concentric to the inside diameter of the pipe. Orifice plates concentricsegmentaleccentric the most common primary flow element is the concentric orifice plate, often called the sharpedged orifice plate. The venturi flow meter obtains a pressure differential by constricting the flow area and. The simplest design of orifice plate is the squareedged, concentric orifice. An orifice plate holder consisting of a set of orifice flanges or an orifice fitting equipped.
Determine where the rosemount 1495 orifice plate, 1496 flange union is to be placed within the piping system. This article provides calculation methods for correlating design, flow rate and pressure loss as a fluid passes through a nozzle or orifice. The venturi, vcone, standard concentric orifice plate and wedge flow meters were tested by hollingshead et al. There are 4 types of orifice plates that we will discuss. A concentric orifice plate is unsuitable for dirty fluids and twophase flows as solid particles or water condensates could sediment in front of the plate causing deteriorationin accuracy and possible blockage. Flow rate is determined based on the difference between pressure readings in the upstream side and the downstream side of the pipe.
Types of orifice plates used in flow measurement learning. The meter consists of the following elements see figure 11. The concentric orifice plate is the most common of the three types. Non concentric orifice plates are designed so that such operating conditions. Venturi, standard concentric orifice plate, vcone, and wedge flow meters shown in fig. The orifice bore is positioned in the exact center of the plate. Apr 02, 2019 lets consider a few typical orifice plate configurations. Our innovative orifice plate line includes a complete selection of solid ptfe, tufsteel, or a 316l stainless steel orifice plate molded to a rubber fab elastomer, in standard, tabbed, and vertical triclamp styles, that can be custom drilled with an eccentric or concentric bore. Nozzles and orifices are often used to deliberately reduce pressure, restrict flow or to measure flow rate. The plate holder has a function of holding the orifice plate and also a function as a gasket to prevent leakage of the process fluid. An orifice plate holder consisting of a set of orifice flanges equipped with the appropriate differential pressure sensing taps.
Eccentric orifice plate is similar to a centric orifice plate with circular opening. As with the eccentric orifice plate design, the segmental hole should be offset downward in gas flow applications and either upward or downward in liquid flow applications depending on. Orifice plates sanitary orifice plate gaskets rubber fab. Orifi ce, plate thick ness e should be thick enough to re duce plate defl ection to a minimum.
An orifice meter consists of an orifice plate, a holding device, upstream downstream meter piping, and pressure taps. Discharge coefficient performance of venturi, standard concentric orifice plate, vcone and wedge flow meters at low reynolds numbers author links open overlay panel c. This is generally the most commonly used type of orifice plate with the orifice bore positioned. Orifice plate sealing units dsc dual seal line sizes 2 to 16 inch the daniel dual seal is the most simple and practical orifi ce plate sealing device for normal fl owing streams. These taps are highly inaccurate, but are cheap to purchase and easy to install. Establish the proper orientation as determined by the intended service for. Orifice plates are flat plates 116 to 14 inch thick. In accordance with iso5167, bs1042, asme mfc 3m, r. Jan 02, 2016 the second offcenter orifice plate type is called the segmental orifice plate, where the hole is not circular but rather just a segment of a concentric circle. This is generally the most commonly used type of orifice plate with the orifice bore positioned along the pipe centreline.
Line sizes 12 and above require the seal to be vulcanized to the o. When it obstructs the flow of a fluid, a differential pressure is produced across the plate. Vent or drain holes are provided as per customers requirement. At the convergence point, the relative mass flow rate imbalance is 3. Plate od bore bevel line id plate od bore line id plate od flow flow flow flow flow throat throat counter bore radius radius standard concentric orifice plates the avco standard concentric orifice plate or flow element fe is manufactured in accordance with asme b16.
Flow through a sharpedged orifice plate is characterized by a change in velocity. Computations are made for five, seven and nine stages. Looking at a side view of a squareedged concentric orifice plate reveals sharp edges 90 o corners at the hole. An orifice plate in its simplest form is a thin steel plate with a circular orifice of known dimensions located centrally in the plate. The concentric orifice plate is also easily reproduced at a relatively low cost. Volume 78, issues 34, september 2011, pages 559566. Orifice plates flow measuring instruments for industrial. The quality of the orifice plate face must be flat within 1% of the dam height.
The concentric bored orifice plate is the most used design because of its proven reliability in a variety of industrial applications and the extensive amount of research conducted on this design. An orifice plate is a thin plate with a hole in it, which is usually placed in a pipe. This type of orifice plate is manufactured by machining a precise, straight hole in the middle of a thin metal plate. With refined data generated, out of coordinated research programs, during 1993 1999, aga report 3 underwent. The most commonly used inferential or rate meter is the thinplate, concentric orifice meter which is the primary device discussed in this paper. An orifice meter is a fluid flow measuring device that produces a differential pressure to infer flow rate. The disc is clamped between two pieces of flange and attached by a seal. As the reliability and accuracy of the orifice was established, its use became more widespread and varied.
Its bore position is offset from the centre line of the pipe. The orifice plate flow detector is the simplest of the flowpath restrictions used in flow detection, as well as the most economical. They rely on differential pressure when fluid flows around an elbow. The holder ring has a function of holding the orifice plate and also a function as a gasket to prevent leakage of the process fluid. These conical entrance orifice plates are used for low reynolds number in the range of 80 to 2000 and give more constant or predictable discharge coefficient. A concentric orifice plate is unsuitable for dirty fluids and twophase flows as solid particles or water condensates could sediment in front of the plate causing deteriorationin accuracy and. Pdf numerical analysis of eccentric orifice plate using. Orifice plates control process flow with orifice plates. Concentric orifice plate article about concentric orifice. Paper open access numerical analysis of eccentric orifice. Depending on the service, these seals are made of nitrile, tfe, or stainless steel. The second offcenter orifice plate type is called the segmental orifice plate, where the hole is not circular but rather just a segment of a concentric circle. Lets consider a few typical orifice plate configurations.
Offered in a concentric or eccentric self draining configuration, the rubber fab orifice plate prevents dead. It is precision molded and provides four metaltometal sealing surfaces 360 around the plate. Orifice plate assemblies with rtj holder the plate holder assembly is a combination of plate holder and an orifice plate designed for ring tongue joint rtj flanges. When designing and configuring orifice plates, there are several factors which must be followed to ensure accurate and reliable measurement. Daniel orifice plates and plate sealing units december 2017 table 4. Much test data has been compiled about orifice plates. By far the most critical part of the meter is the orifice plate, particularly the widely used squareedged concentric plate, whose construction requirements are well documented in standards such as aga3 and iso 51671. In the case of a simple concentric restriction orifice the fluid is accelerated as it passes. At lower reynolds numbers, the discharge coefficient of square edge orifice plate may change by as much as 30%. Rosemount 1495 orifice plate, 1496 orifice flange union.
Plate od bore bevel line id plate od bore line id plate od flow flow flow flow flow throat throat counter bore radius radius standard concentric orifice plates. Mk52 bore diameter as spe cified by customer, front elevation weight in pounds side sectional elevation blank plate. Concentric orifice plates represent the majority of plates used in all orificebased devices. The most common design is the thin concentric orifice plate answer a, which operates in the turbulent flow regime. Calculation of flow through nozzles and orifices neutrium. Concentric, eccentric, segmental or quadrant edge bores as required. The plate is similar to the type 500 orifice plate but has a 2in. Orifice plates concentric segmentaleccentric the most common primary flow element is the concentric orifice plate, often called the sharpedged orifice plate. When the cross sectional area is oriented downward of circular piping, it enables flow of impurities in the measured fluid through the orifice plate without forming deposits and sediments in front of. An orifice is an opening of a specific dimension removed from the head orifice plate which can be characterised by its shape or type of edge in the side base of a show more content best results occur between value of 0. The importance that all criteria are met is essential.
Establish the proper orientation as determined by the intended service for the orifice plate. Pdf in this paper the eccentric orifice plate is qualitative analysed as compared with the classical concentric orifice plate from the point of view. Concentric orifice plates represent the majority of plates used in all. Eccentric orifice plate consists of these main parts. Orifice plate holder a pressure containing piping element, such as a. Determination of influence of parameters on undercarriage shock absorber.
Analysis of flow through multistage orifice assembly with concentric and annular orifice assemblies. Discharge coefficient performance of venturi, standard. The meter tube consisting of the appropriate adjacent piping sections, with or without flow conditioners and temperature wells. The most commonly used inferential or rate meter is the thin plate, concentric orifice meter which is the primary device discussed in this paper. An introduction to an orifice meter 909 words bartleby. Orifice plate the orifice plate is considered to be the heart of the primary element. The plate would normally be clamped between adjacent flange fittings in a pipeline, a vent hole and drain hole being provided to prevent solids. It is designed to fit between two flanges and has a. The pressure drop across an orifice is a function of the flow rate through the. Rubber fab technologies groups concentric and eccentric. When a fluid whether liquid or gaseous passes through the orifice, its pressure builds up slightly upstream. The concentric bored orifice plate is the most used design because of its proven reliability in a variety of industrial applications and the extensive amount of research conducted on this. The venturi flow meter obtains a pressure differential by constricting the flow area and therefore increasing the velocity at the constriction, which creates a lower pressure according to bernoullis theorem.
An orifice is an opening of a specific dimension removed from the head orifice plate which can be characterised by its shape or type of edge in the side base of a show more content best. Orifice plates, orifice plates manufacturers, types of. Orifice plate a thin squareedged plate with a machined circular bore concentric with the meter tube i. The specifications of the orifice plate are detailed in section 2. Line sizes 210 require a removable orifi ce plate seal. The eccentric orifice as a flow measuring device in small. It is known that if severe cavitation occurs at piping in which the restriction orifice is installed, the trouble such as pipe vibration, noise and pipe erosion may occur. As a rule, the maximum pressure drop across a single orifi ce for a gas is 50%. Offered in a concentric or eccentric self draining configuration, the rubber fab orifice plate prevents dead legs, maintains flow while assuring self drainage thereby eliminating the potential for soil retention. Eccentric answer c and segmental answer f orifice plates can handle similar applications for fluids with solids in liquid or liquids in gas. Confirm the rosemount 1495 andor 1496 configurations. Eccentric answer c and segmental answer f orifice plates can.