Area at Choke Section of Sprue Calculator

Sprue Area Formula:

\[ A = A_t \times \sqrt{\frac{h_t}{h_c}} \]

Area at Top Section:

m²

Metal Head at Top Section:

Head at Choke Section:

Tolerance:

Area at Choke Section (m²):

Acceptable Range (m²):

1. What is Area at Choke Section of Sprue?

Definition: The area at the choke section of a sprue is the cross-sectional area at the narrowest point where the sprue runs full of metal during casting.

Purpose: This calculation is crucial for designing gating systems in metal casting to ensure proper metal flow and mold filling.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ A = A_t \times \sqrt{\frac{h_t}{h_c}} \]

Where:

\( A \) — Area at choke section (m²)
\( A_t \) — Area at top section (m²)
\( h_t \) — Metal head at top section (m)
\( h_c \) — Head at choke section (m)

Explanation: The formula accounts for the relationship between metal head pressure and flow area in the sprue system.

3. Importance of Choke Area Calculation

Details: Proper choke area ensures controlled metal flow, prevents turbulence, and helps achieve complete mold filling without defects.

4. Using the Calculator

Tips: Enter the top area, metal head, choke head, and tolerance percentage (default ±5%). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical tolerance for choke area?
A: A ±5% tolerance is common, but this may vary based on casting requirements and material.

Q2: Why is the choke section important?
A: The choke section controls the metal flow rate and helps maintain the required pressure in the gating system.

Q3: How does metal head affect the choke area?
A: Higher metal head increases the flow velocity, requiring careful choke area calculation to maintain proper flow characteristics.

Q4: What happens if the choke area is too small?
A: Excessive flow velocity can cause mold erosion, turbulence, and gas entrapment in the casting.

Q5: What happens if the choke area is too large?
A: Insufficient flow velocity may lead to incomplete mold filling or cold shuts.