Leak Detectors for Pressurised Fuel Lines (non-flammable liquids only)

SGB VLR Vacuum Leak Detector

A vacuum (underpressure) is generated in the interstitial space of the double-walled pipe system. Minor leaks cause a loss of vacuum, which is automatically compensated by integrated pumps to maintain stable operation.

Significant leaks are reliably detected, triggering both optical and acoustic alarms.

The pipe run and installation height in relation to the leak detector position determine the required underpressure.

Minimum Alarm Pressure

Formula:
Minimum alarm pressure (mbar) = 30 mbar + H_max (cm) × density (g/cm³) × 0.98

For underground pipes: density ≥ 1 g/cm³ (see documentation for H_max values).

An Excel tool is available for calculating the minimum alarm pressure.

The alarm pressure (in mbar) is indicated in the model type, e.g. VLR 410.

Operating Conditions

The system operates at pressures higher than the alarm pressure. The pipe’s interstitial space must be capable of withstanding these vacuum levels.

Applications

VLR leak detectors are designed for one pipeline or multiple pipelines via manifolds. They are suitable for wall mounting (indoors or outdoors) and are widely used for:

• Heating oil storage tanks
• Diesel tank farms
• Tank farms storing chemically aggressive liquids (with suitable design)

Important Notes

• Always follow the requirements in the official documentation.
• All components in contact with stored liquids or vapours must be made of sufficiently durable materials.
• VLR leak detectors must not be installed in Ex zones or exposed to explosive vapour–air mixtures.