DESIGN
Generally, weld-in orifice plates are utilized for high pressure and high temperature applications, e.g. in power plants. They can be manufactured with or without a ring chamber tapping. Throat and body material are recommended to be the same but in some cases, if body material is non-alloy carbon steel, a stainless steel orifice plate can be welded with suitable welding method to the two body parts or chambers. If needed, we can weld inlet and outlet pipe sections to the orifice plate.
ADVANTAGES
Weld-In flow elements are the recommended choice for high pressure and high temperature application because they avoid any kind of leakage.
The single bore tappings are easy to clean and thus suitable for process fluids which may have some solids, may be resinous or for plants which are not operating constantly. The ring chamber design ensures that the pressure values are averaged over the cross section. This results in a steady measurement signal.
MEASURING UNCERTAINTY
Uncertainty of Orifice Plates are 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
PN 40 to PN 400 (EN) / 150# to 2500# (ASME)
MAIN PIPE CONNECTION TYPE
Weld preparation according to EN ISO 9692 (DIN 2559), ASME B16.25 or customer standard.
PRESSURE TAPS
We manufacture three different tapping design according to ISO 5167:
- Flange Tapping
- Corner Tapping
- D and D/2 Tapping
We furnish tapping connections with condensate pots, root valves (gate or globe valve) and other fittings, as required.
Tapping ends are designed according to requirement:
- Plain end for fitting
- Butt weld end
- Threaded end (male or female)
- Flanged end
- Compression fitting (suitable for direct instrument tubing connection)
- Special end design according to requirement
MATERIAL
The material is chosen based on process medium, pressure and temperature. The pressure tap material is selected to be equivalent to the pipe material.
Commonly used material for welded orifice plate body are:
- P250GH (C22.8), 1.0460, ASTM A105
- 16Mo3, 1.5415, ASTM A182 Gr. F1
- 13CrMo44 or 13CrMo45, 1.7335, ASTM A182 Gr. F11
- 10CrMo9-10, 1.7380, ASTM A182 Gr. F22
- X10CrMoVNb9-1, 1.4903, ASTM A182 Gr. F91
- X2CrNi18-9 or X2CrNi19-11, 1.4307 or 1.4306, ASTM A182 Gr. F304L
- X2CrNiMo17-12-2, 1.4404, ASTM A182 Gr. F316L
- Hastelloy C-276, 2.4819, N 10276
- Monel 400, 2.4360, N 04400
EXAMPLE DESIGN
Single Tapping
Annular Chamber
INSTALLATION
Orifice plate body is welded directly to pipeline. Installation must be done according to assembly drawing which we prepare separately for each flow element.
QUALITY CONTROL
Our design and manufacturing are qualified according to ISO9001. 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.