DF Standard Nozzle Flowmeter
The standard nozzle features a rounded-profile design that offers low pressure loss, short straight-pipe run requirements, and high accuracy. It is particularly suited to flow measurement of high-temperature, high-pressure steam and high-velocity fluids in power plants, and complies with ISO 5167-3:2022. The unit is integrally forged without welded seams, ensuring safe and reliable operation.
Technical data
| Accuracy: | In accordance with ISO 5167-3 | Nominal Size: | Standard: 50–500 mm; Chuanyi: 50–1,500 mm |
| Nominal Pressure: | ≤42 MPa (welded type) | Process Temperature: | -40°C to +555°C |
| Design Type: | ISA 1932/Annular chamber/Welded/Long-radius nozzle |
Features & Benefits
Arc-Shaped Contour, Low Loss, Short Straight Pipe
The nozzle features an arc-shaped inlet contour that accelerates the fluid smoothly along a curved surface with a clean separation point. Permanent pressure loss is only a fraction of an orifice plate, and the device is insensitive to upstream flow disturbances—requiring far shorter straight runs while maintaining accuracy and reducing energy consumption.
Built for High Temperature and High Pressure
The monolithic structure is engineered for high-temperature, high-pressure service, withstanding the thermal shock and water hammer typical of power plant main steam and feedwater lines. In services above 400 °C and Class 600 and above, it resists deformation and fatigue over long-term operation—a proven choice for power plant throttling applications.
Monolithic Forging, No Welds, Safe and Reliable
The nozzle body is forged as one solid piece with no welded joints, fundamentally eliminating risks such as weld cracking and heat-affected zone corrosion. High structural rigidity and long fatigue life deliver outstanding safety in units with frequent startups, shutdowns, and pressure swings.
High Accuracy, Excellent Repeatability, Stable Discharge Coefficient
Precision-machined arc geometry delivers a discharge coefficient that remains stable and drift-free over time, with accuracy and repeatability superior to conventional orifice plates. The wide turndown ratio maintains accurate measurement at both low and high load—ideal for cycling power units.
Corrosion Resistant for Critical High-Safety Applications
Forged from stainless or alloy steel, with a surface resistant to steam oxidation and corrosion. Beyond conventional power plants, it suits nuclear-grade and other critical lines demanding the highest safety, with minimal maintenance over the full service life.
Applications
Power:
Main steam, main feedwater, and desuperheating water (ultra-high temperature up to 555°C, ultra-high pressure up to 42 MPa)
Nuclear power:
Nuclear-grade main feedwater flow measurement (FeIV-class welding qualification, leak-tight design)
Petrochemical:
High-temperature, high-pressure process gas
Boiler systems:
Superheated steam flow monitoring
Case Studies
Sinopec Maoming Petrochemical Company – Refining and Chemical Units
Sinopec Maoming Petrochemical is a large domestic refining and chemical integration base. 16 DF series standard nozzles (type DFBPH) serve steam, process gas, nitrogen and circulating water lines across the units, configured across multiple pressure ratings and delivered in batches, supporting flow measurement and energy control in refining and chemical units.
Shandong Ruilin Polymer Materials Co., Ltd. – Green Low-Carbon Olefin Integration Project
Shandong Ruilin Polymer Materials is a large petrochemical and polymer producer, developing a green low-carbon olefin integration project and PO/TBA/MTBE co-production complex. 36 DF series standard nozzles (type DFBPH) serve steam, process gas and circulating water lines across the plant, supplied as a complete batch to support flow measurement and energy accounting in large chemical units.
Shandong Yulong Petrochemical Co., Ltd. – Yulong Island Refining and Chemical Integration Project
Shandong Yulong Petrochemical is a national key large-scale refining and chemical integration project. 10 DF series nozzles have been supplied in batches, including standard, standard welded and Venturi nozzle types with F11 and A105 butt-weld stop valves, with product certification and certificates of origin provided to meet imported equipment matching requirements of large refining projects.
