1. What is GPM to Inches of Water Conversion?

Definition: This calculator converts pressure measured in pounds per square inch (psi) derived from gallons per minute (GPM) flow to inches of water column (inH₂O).

Purpose: It helps engineers, plumbers, and technicians working with fluid systems to convert between these common pressure units.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{in} \) — Pressure in inches of water (inH₂O)
• \( P_{psi} \) — Pressure in pounds per square inch (psi)

Explanation: The conversion factor 27.68 comes from the relationship where 1 psi equals approximately 27.68 inches of water column at standard conditions.

3. Importance of Pressure Unit Conversion

Details: Different industries use different pressure units. This conversion is particularly important in HVAC, plumbing, and fluid dynamics applications where water column measurements are common.

4. Using the Calculator

Tips: Simply enter the pressure value in psi (must be > 0) and the calculator will automatically compute the equivalent in inches of water.

5. Frequently Asked Questions (FAQ)

Q1: Why is the conversion factor 27.68?
A: This is based on the standard conversion where 1 psi equals the pressure exerted by a 27.68-inch column of water at 4°C.

Q2: Does temperature affect this conversion?
A: Slightly. The 27.68 factor is for water at 4°C (39.2°F). For warmer water, the factor decreases slightly as water density decreases.

Q3: When would I need to convert psi to inH₂O?
A: Common applications include sizing pressure regulators, calibrating manometers, and working with low-pressure gas systems that use water column measurements.

Q4: Is this conversion only for water systems?
A: While the units reference water, the conversion applies to any fluid system when working with these pressure units.

Q5: How precise is this conversion?
A: For most practical applications, 27.68 is sufficiently precise. For scientific work, you might use 27.6799046 inH₂O/psi.