SEDEM-Caudal

Fernando Algaba +34 93 289 71 37 falgaba@sedemsa.es

Expert solutions in manufacturing flow primary elements

SEDEM designs and manufactures normalized primary elements for flow measurement: orifice plates between orifice flanges, assemblies of orifice plate and flanges with calibrated meter-run, nozzles, Venturi tubes, Pitot tubes, and single, multi-orifice or multi-stage restrictors.

These flow devices have a reduced fluid passage section leading to increased speed and reduced pressure, generating so a different pressure proportional to flow between upstream and downstream sections of the device.

Its design is based on the Bernoulli equation concerning fluid dynamics and its manufacture is in accordance with international standards EN ISO 5167 and ASME for measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full.

These equipments are subject to the tests and treatments determined by regulations, in addition to those required by the customer and recommended by SEDEM.

The flow primary elements operate in combination with differential pressure transmitters that convert this into an electrical signal 4-20 mA, HART and PROFIBUS proportional to the flow.

Our product managers will offer you the best solution. Contact us.

Assembly of drilled diaphragm mounted between orifice flanges for pressure taps.

The plate may have concentric, eccentric or segmental orifice, presents a right angle upstream and a bevel downstream, provides an identification tab and is mounted between gaskets and flanges.

Pressure taps are machined directly into the flanges, incorporated in the plates or in annular chambers. They can be straight or angled (corner taps) and extensions to ease connection or access are available.

Flanges provide multiple solutions in materials, size, pressure rating and gasket faces to meet the different customer requirements and process conditions. Connection to process line is by welding.

This solution for flow measurement is the most common, reliable and economical, simple installation and maintenance.

Specifications:

  • Suitable for: liquids, gases and steam
  • Uncertainity: ≤ +0.5% of flow
  • Materials: carbon-, stainless-, special-steel and alloys

Contact SEDEM for more information.

Drilled diaphragm mounted between orifice flanges for pressure taps, wich assembly is installed between two sections of calibrated meter-run.

The plate may have concentric, eccentric or segmental orifice, presents a right angle upstream and a bevel downstream, provides an identification tab and is mounted between gaskets and flanges.

Pressure taps are machined directly into the flanges, incorporated in the plates or annular chambers. They can be straight or angled (corner taps) and extensions to ease connection or access are available.

Orifice flanges provide multiple solutions in materials, size, pressure rating and gasket faces to meet the different customer requirements and process conditions. Connection to meter-run is by welding.

The calibrated meter-run consists of two pipe sections machined under standarized exigencies of inner roughness and diameter tolerance because their influence on flow measurement. The preceding -or upstream- section requires be longer than later -or downstream- section to stabilize the fluid, both in relation to its diameter and in respect of the position of the orifice plate. Connection to process line may be welded or flanged.

The above parts constitute a single equipment, sized 25 to 50 mm of internal diameter, according to standards, or larger sizes than DN50, if calibration required.

Specifications:

  • Suitable for: liquids, gases and steam
  • Uncertainity: ≤ +1% of flow (uncalibrated)
  • Materials: carbon-, stainless-, special-steel and alloys

Contact SEDEM for more information.

Curved tubular inlet section converging into a cylindrical neck which is inserted inside a calibrated meter-run or installed between flanges.

The different types are:

  • ISA 1932 nozzle: Inlet section of 50
  • Long radius nozzle: Inlet section of 50
  • ASME PTC-6 nozzle: Inlet section of 50
  • Venturi-nozzle: Inlet section of 65

Among the advantages of this measuring solution highlight more flow allowance, less distance upstream requirement and lower permanent pressure drop than orifice plate. The rigidity of its construction, of low maintenance, support higher pressure and temperature.

Specifications:

  • Suitable for: liquids, gases and steam; abrasive fluids and high speeds and temperatures
  • Sizes: from 2” to 24”
  • Uncertainity: ≤ ±1% (ISA nozzles) and ±2% (Long Radius nozzles) of flow
  • Materials: carbon- (only meter-run), stainless-, special-steel and alloys

Contact SEDEM for more information.

Tubular section of conical inlet converging to a cylindrical neck followed by a divergent conical outlet.

Its construction may be from machined bar or welded steel plate, depending on the diameter, and its process connection is performed by welding or between flanges.

The fluid increases the speed in the narrow passage to recover in part its original pressure in the diverging section.

The main advantages of Venturi tubes are:

  • Wide flow range as its coefficient of discharge hardly varies with Reynolds number
  • Less loss of permanent load than orifice plates and nozzles at same flow
  • Greater recovery of differential pressure produced and therefore energy saving
  • Lower requirement for straight lengths of inlet and outlet than orifice plates and nozzles

Specifications:

  • Suitable for: liquids, gases and steam, particularly at low flow and pressure
  • Sizes: from 2” to 10” (machined bar) and from 8" to 48" (steel plate)
  • Uncertainity: ≤ ±1% (machined bar) or ±1.5% (steel plate) of flow
  • Materials: carbon- (only meter-run), stainless-, special-steel and alloys

Contact SEDEM for more information.

Angled or straight pipe inserted into a pipe or conduit with inlets facing to the flow direction.

Its construction does not meet a specific standard; each manufacturer determines the constant of proportionality between differential pressure and flow depending on their design. The Pitot tube is, perhaps, the oldest way to measure flow.

The main advantages of Venturi tubes are:

  • Simple and economical instrument
  • Valid for wide size range
  • Low loss of permanent load
  • Easy installation and removable under service

Specifications:

  • Suitable for: liquids and gases, particularly in large pipe diameters
  • Sizes: from >2”
  • Uncertainity: ≤ ±3% of flow

Contact SEDEM for more information.

Plate with one or multiple orifices, or sequence of them inserted into a pipe section.

Its function is to obtain a pressure reduction or a flow limitation.

The calibrated bores force a calculated reduction of pressure. Case of high pressure drops or high noise levels, are chosen multi-orifice or multi-stage restrictions to achieve the required pressure reduction progressively. This calculation is determined from the characteristics of the fluid and the process data.

Single or multi-orifice restrictions mounting is between flanges and process connection of multi-stage restrictions is performed by welding or flanges.

Specifications:

  • Suitable for: liquids, gases and steam
  • Sizes: from <1” to >20"

Contact SEDEM for more information.