Hydrostatic Testing Calculator

Calculate working pressure, test pressure, and make-up water allowance

Step 1: Determine Minimum Required Working Pressure (WP)

WP = (RP + H1 + FL) × FoS
Auto-filled based on system year
HMDH above lowest point
From hydraulic calculations or use 100 kPa minimum
Auto-filled based on system year (can be manually changed)

Reference Tables

Table D.1: Minimum Residual Pressure

Year(s) Fire Hydrant System Minimum Residual Pressure (kPa)
1921 to 1974 HOB Act / CA17 700
1974 to 1994 Ordinance 70 700
1994 onwards AS 2419.1 700

Table D.2: Minimum Required Factor of Safety

Year(s) Fire Hydrant System Factor of Safety
1921 to 1974 HOB Act / CA17 1.25
1974 to 1994 Ordinance 70 1.25
1994 onwards AS 2419.1 1.5

Step 2: Determine Hydrostatic Test Pressure (HTSP)

HTSP = WP +/- H2
Enter the WP calculated from Step 1
Height from booster to lowest point in system

Step 3: Determine Make-Up Water Allowance

⚠️ Important: Make-up water must not exceed the calculated allowance for the system to pass the hydrostatic test.

Testing Procedure & Acceptance Criteria

📋 Testing Procedure

Follow the standard hydrostatic testing procedure as outlined in the relevant fire hydrant system standard (AS 2419.1, Ordinance 70, or HOB Act/CA17).

✅ Acceptance Criteria

The system passes if the make-up water required during the test period does not exceed the calculated allowance above.