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ORIFICE PLATE

Orifice plates are used as flow elements for flow measurement of single phase aggressive and non-aggressive gases and liquids. Orifice plates must be assembled together with flanges for proper utilization.

DESIGN

Orifice plates have handle or paddle used for handling and marking the orifice plate information such as tag number, process conditions etc. Orifice plates are mounted between flanges and gaskets. Depending on the process conditions, the plate type may be manufactured as

  • square edged concentric
  • quarter circle entrance
  • segmental
  • plate with conical entrance
  • conditioning (multiple holes)

orifice plate - single plate

according to the relevant standards (ISO 5167, ASME MFC-3M, etc.). The plate type is chosen based on the specific process conditions. Orifice plates are made from a wear-resistant material like stainless steel.

PRESSURE TAPS

The measurement standards differentiate between three types of pressure taps:

  • flange tapping (image 1) where a1 = a2 = 25,4 mm
  • pipe tapping D – D/2 (image 2) where a1 equals the pipe inner diameter D and a2 equals D/2
  • corner tapping in the flange (image 3) which is based on standardized corner tapping

Special tappings (e.g. Vena Contracta) are also available and will be calculated respectively.

orifice plates - tappings

 

ADVANTAGES

  • Low price design
  • Easy Installation

MEASURING UNCERTAINTY

 Uncertainty of Orifice Plates is between 0,5% – 1,2%, depending on the application. The uncertainty depends on Beta Ratio and Reynolds Number.

PRESSURE LOSS

The pressure loss depends on the diameter ratio β (d/D) and amounts to approx. 30 – 80% of the differential pressure.

NOMINAL DIAMETER (according to ISO 5167)

DN 50 to DN 1000 / 2“ to 40“ (if requested other sizes are possible)

PRESSURE RATING

up to PN 400 (EN) / 2500# (ASME)

PLATE SEALING SURFACE

Sealing surface are designed according to EN 1092-1:

  • flat (form B1 and B2)
  • groove (form D)
  • tongue (form C)
  • female (form E)
  • male (form E)

Surfaces according to ASME B16.5:

  • flat (RF and SF)
  • groove (small/large)
  • tongue (small/large)
  • male/female (small/large)
  • RTJ male or female

orifice plates - face surfaces

Surfaces can also be designed according to other flange standards specified by the customer.

OUTER DIAMETER "D"

The outer diameter of the plate is designed to fit between the respective flanges of the customer.

THROAT DIAMETER "d"

The calculation of the bore diameter is based on the supplied process data. All relevant standards and regulations will be considered. The calculation is part of the scope of supply.

MARKING

Orifice Plate Paddles are marked by lazer marking. The marking consists:

  • Tag no. of flow element
  • Pressure rating
  • Size or Dimensions
  • Throat Diameter
  • Material
  • Direction of flow (Upstream and Downstream marking)

PLATE THICKNESS "E"

The plate thickness “E” as well as the dimensions of the tag handle depend on the nominal diameters and are based on DIN 19206 Parts 1-3 and the relevant ASME/API standards.

MATERIAL

The material of orifice plates is chosen based on process medium, pressure and temperature. 304 and 316 are the most commonly used stainless steel materials for orifice plates.

INSTALLATION

Mounted between flanges according to EN 1092-1 / ASME B 16.5 or other standards such as DIN, JIS or BS. The pipe may be positioned horizontally, vertically or sloped.

QUALITY CONTROL

Our design and manufacturing are qualified according to ISO 9001. Manufacture and test works are done in accordance with relevant codes and standards. These are PED, EN 14380, ASME Section XIII etc.

Each product is inspected and certified with EN 10204 3.1 certificate. If requested, 3.2 certification is available.