Internal Diameter of Stuffing Box Calculator

Internal Diameter Stuffing Box Formula:

\[ d_{sb} = d_{shaft} + 2 \times c \]

Internal Diameter Stuffing Box: mm

1. What is Internal Diameter of Stuffing Box?

Definition: The internal diameter of a stuffing box is calculated to determine the correct packing size by measuring the shaft diameter and adding clearance.

Purpose: This calculation ensures proper sealing and prevents damage to shafts during operation.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ d_{sb} = d_{shaft} + 2 \times c \]

Where:

\( d_{sb} \) — Internal diameter of stuffing box (mm)
\( d_{shaft} \) — Diameter of shaft (mm)
\( c \) — Clearance between shaft and stuffing box (mm ±5%)

Explanation: The shaft diameter is increased by twice the clearance value to account for proper packing space on both sides of the shaft.

3. Importance of Proper Clearance

Details: The ±5% clearance tolerance ensures proper sealing while preventing excessive friction that could damage the shaft.

4. Using the Calculator

Tips: Measure the shaft diameter accurately and use manufacturer-recommended clearance values (typically ±5% of nominal clearance).

5. Frequently Asked Questions (FAQ)

Q1: Why is clearance important in stuffing box design?
A: Proper clearance prevents shaft damage while allowing effective sealing through proper packing compression.

Q2: What happens if clearance is too small?
A: Insufficient clearance can cause excessive packing compression, leading to shaft wear and increased friction.

Q3: What happens if clearance is too large?
A: Excessive clearance may prevent proper sealing, causing leaks and requiring more frequent packing replacement.

Q4: How do I measure shaft diameter accurately?
A: Use precision calipers to measure the shaft diameter inside the stuffing box area if possible.

Q5: Why the ±5% tolerance?
A: The tolerance accounts for manufacturing variations while maintaining effective sealing performance.