Daehan Instruments
Practical flow-metering technology - Korean Manufacturer since 1989
Daehan InstrumentsPractical flow-metering technology - Korean Manufacturer since 1989
Precision orifices for pressure and flow restriction
A restriction orifice is a precisely designed differential-pressure device used to reduce pressure or restrict flow in a piping system
Unlike an ordinary measuring orifice, a restriction orifice is used to deliberately reduce system pressure or limit flow. With 35 years of accumulated design know-how, Daehan Instruments achieves cavitation prevention, noise reduction and minimal erosion.
Restriction orifice solutions optimized for the application and operating conditions
The most basic form, reducing pressure with a single orifice; an economical solution for low-to-medium differential pressures.
Where a large pressure drop is required, the pressure is reduced in several stages to effectively control cavitation and noise.
A special multi-hole design that splits the fluid into many small jets to minimize noise and vibration.
A cylindrical cage structure disperses the fluid through 360 degrees, ensuring stable performance even under extreme conditions.
A variable design that lets the orifice size be adjusted as operating conditions change, allowing flexible operation.
Maintains sonic flow conditions to guarantee a constant flow rate regardless of downstream pressure changes.
Precision design and manufacturing specifications compliant with international standards
| Item | Specification | Remarks |
|---|---|---|
| Standards | ISO 5167, ASME MFC-3M, API RP 550 | International Standards Compliance |
| Pipe Size | 1/2" ~ 60" (DN15 ~ DN1500) | Large diameters available on request |
| Pressure rating | Class 150 ~ Class 2500 | ASME B16.5 / B16.47 |
| Pressure Drop Ratio | ΔP/P1 = 0.05 ~ 0.95 | With multi-stage |
| Temperature range | -196°C ~ +650°C | Cryogenic/high-temperature service |
| Materials | 316L SS, Hastelloy, Monel, Inconel, Titanium | Corrosive fluid service |
| Bore Accuracy | ±0.025mm (±0.001") | Precision machining |
| Surface Roughness | Ra ≤ 0.8 μm | Mirror finish available |
| Noise Level | < 85 dBA @ 1m | With multi-stage design |
| Cavitation Index | σ > σc (Critical) | Effective cavitation prevention |
Key formulas for precise pressure drop and flow calculation
K: resistance coefficient, ρ: fluid density, V: velocity
d: orifice bore, Q: flow rate, Cd: discharge coefficient (0.61–0.65)
P2: downstream pressure, Pv: vapor pressure, ΔP: pressure drop
Restriction orifice solutions proven across industries
Strict quality control and thorough performance verification
Every restriction orifice is managed under the ISO 9001:2015 quality management system from design through manufacturing and inspection, and ships only after passing Daehan Instruments' strict quality inspection refined over 35 years.
Beyond supplying products, Daehan Instruments provides comprehensive engineering services covering the entire process from design to commissioning.
Engineers with 35 years of experience propose the optimal pressure control solution