DESCRIPTION
FEPL’s flow nozzle is a flow measurement device which used for measurement of high velocity flow, such as high pressure steam. It can also be used with other fluids such as water, air or other gases.
The typical profile of this device offers a smooth passage to the fluid which leads to the lesser pressure drop and thus more efficiency.
The rounded profile is particularly useful when the steam contains particles which damage the edges of the flow element which doesn’t happen due to the smooth profile. Thus the product life is increased.
SALIENT FEATURES
- Best suitable for measurement of high pressure high temperature high velocity steam measurement.
- Smooth profile and rigid structure makes the assembly extremely stable.
- Free from leakage (when provided in weldin type assembly).
- Zero maintenance since no moving parts.
- Repeatability: 0.3%
- Less straight lengths requirement.
DESIGN & MANUFACTURING STANDARD
- ISO-5167 part III
- ASME PTC-19.5
- ASME PTC-6
CLASSIFICATION
The flow nozzle can be classified as follows
BASED ON ELEMENT
- Long Radius High Beta
- Long Radius Low beta
- ISA 1932
BASED ON MOUNTING
- Welding type
- Flanged type
- Holding ring type
BASED IN APPLICATIONS
- Used in high accuracy area of turbine steam flow measurement Flanged type with throat tap nozzle (as per PTC-6 standard) with accuracy in a tune of 0.25%.
MATERIALS
Selection based on temperature and process conditions.
Typically used materials are:
- Element: SA.182 F316/ SA182 F11 / SA182 F22 / SA182 F91
- Pipe: SA.106Gr. B / SA335 P11 / SA335 P22 / SA.335P91
- Flange material: SA105 / SA182F11 / SA182F22 / SA182 F91
ISA 1932 TYPE NOZZLE
The profile of this type of nozzle is formed with the intersection of 2 circles. This gives an estimated uncertainty of 0.8% to 1.2%, depending on the beta ratio.
- Size limits: 50 mm to 500 mm
- Beta Ratio: 0.3 to 0.8
Reynold’s Number:
- For beta 0.3 to 0.44 >> 7 x 10^4 to 10^7
- For beta 0.44 to 0.8 >> 2 x 10^4 to 10^7
Pressure tapping:
- Upstream tap >> Corner tap
- Downstream tap >> @ 0.15D for beta <0.67
- Downstream tap >> @ 0.2D for beta >0.67
OR
- Downstream tap >> corner tap
A Welding type assembly typically with a pipe length 750 mm on upstream side and 250 mm on downstream side. Flanged type assembly can be supplied with or without spool piece as per requirement.
This can be offered in all the 03 mounting classifications. But this has certain manufacturing limitations to use with weldin type, when the line size is small.
