⚡ Restriction Orifice Sizer

Size thick-plate single or multi-hole restriction orifices (ISO 5167 / Crane TP410) for permanent pressure dissipation and cavitation check.

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated

Fluid Mechanics

📊 Solver Telemetry ● ACTIVE

👁️ Views 28

⚡ Solves 23

💾 Downloads 465 📦 Fortran Code 4.4 KB

📅 Released Jun 2026

⏱️ Latency < 1 ms

⚡ Thick-Plate Restriction Orifice Jet & Pressure Recovery

Real-time visual simulation of vena contracta jet contraction & permanent head loss

📝 Configuration & Presets

💧 Pump Recirc (ΔP=20 bar) 🔥 Fuel Gas (ΔP=2.5 bar) ❄️ Chilled Water (ΔP=1.2 bar) ♨️ Multi-Hole Blowdown (55 bar)

⚙️ Fluid & Pipe Flow Rate

Service Fluid Phase:

Pipe Inside Diameter D [mm]:

Mass Flow Rate W [kg/h]:

Fluid Density ρ [kg/m³]:

⚡ Pressures & Restriction Drop

Upstream Pressure P₁ [bar absolute]:

Required Permanent Loss ΔP_perm [bar]:

Liquid Vapor Pressure P_v [bar a]: Used to verify cavitation index σ

Number of Orifice Holes: Multi-hole plates reduce noise & cavitation

Restriction Orifice Formulations:
• Permanent Loss Ratio: ΔP_perm / ΔP_o = 1 − β^1.9
• Orifice Flow: Q = C_d · A_o · √[ (2 ΔP_o) / ρ ] / √(1 − β⁴)
• Cavitation Index: σ = (P₂ − P_v) / ΔP_perm
• Plate Thickness: t_min = d_o · √[ (3 ΔP) / (4 S_allow) ]

📊 Restriction Sizing Results

📊 Output Summary
💾 Fortran Source

Calculated Orifice Bore Hole Size

d_o = 39.81 mm

Diameter Ratio: β = 0.2654 (d/D)

Plate Thk = 1018 mm

Cavitation Index (σ) 3.14 ✅ SAFE / NO CAVITATION

Downstream Pressure (P₂) 3.80 bar(a) Permanent Loss = 1.20 bar

Orifice Bore Area 1244.9 mm² 1 hole(s) × 1244.9 mm²

Volumetric Flow Rate (Q) 45.00 m³/h Discharge C_d = 0.62

📈 Orifice Bore Hole (d_o) vs Permanent ΔP

📉 Cavitation Index (σ) vs Pressure Drop

=================================================================
 THERMOFLUIDCALC — THICK-PLATE RESTRICTION ORIFICE REPORT
=================================================================
Case Title                 : HVAC Chilled Water Branch Balancing Diaphragm
Pipe Inside Diameter (D)   : 150.00 mm
Mass Flow Rate (W)         : 45,000.0 kg/h
Upstream Pressure (P1)     : 5.00 bar(a)
Downstream Pressure (P2)   : 3.80 bar(a)
Permanent Pressure Loss    : 1.20 bar (120.00 kPa)
Number of Orifice Holes    : 1
-----------------------------------------------------------------
ORIFICE BORE DIAMETER (do) : 39.812 mm each
Diameter Ratio Beta (d/D)  : 0.2654
Cavitation Index (Sigma)   : 3.142 (✅ SAFE / NO CAVITATION)
Recommended Plate Thickness: 1018.0 mm
=================================================================

📘 Calculation Methodology & Crane TP410 Standards

Permanent Pressure Loss Recovery

Unlike flowmeter orifices, restriction orifices are sized for permanent non-recoverable pressure dissipation based on Crane TP410 loss ratio:

                    ΔPperm / ΔPo = 1 − β1.9
                

Cavitation Index & Multi-Hole Plates

When $\sigma < 1.5$, severe cavitation erosion risks arise. Splitting the flow across multiple small holes or multi-stage plates elevates cavitation resistance.

Key Engineering Assumptions

Square-edged thick restriction orifice plate ($t \ge 0.05 D$).
Discharge coefficient $C_d = 0.62$ in high Reynolds turbulent flow.
Stainless steel 316 / Monel plate bending stress limit per ASME Section VIII.

ThermoFluidCalc Engineering Report