Grounding of Tank Trucks

A proper grounding system for tank trucks is essential to prevent static electricity and reduce the risk of ignition during loading and unloading. Below are the key requirements for an ideal grounding system

Grounding System

Requirements for a Safe Grounding System

1. Verified Ground Connection
The system must have a controlled and documented ground connection that is regularly inspected by a qualified electrical engineer.

2. Defined Ground Point on the Vehicle
The truck must have a clearly marked ground point with metal-to-metal contact to both the chassis and tank. The resistance in this connection must be less than 10 ohms. The ground point typically consists of a brass stud or stainless steel tab.

3. Standards Compliance
The grounding system must comply with applicable international standards, guidelines, and industry practices, such as:

API RP 2003

IEC TS 60079-32-1

NFPA 77

4. Installation and Maintenance According to Manufacturer’s Guidelines
The system must be installed in accordance with Ex requirements and the manufacturer’s specifications, and undergo routine maintenance by a qualified electrician.

Types of Grounding Systems

Resistance-Based Grounding Systems

These systems provide visual indication and interlocking capability. However, their ability to accurately measure low resistance varies significantly.

Examples of high-performance systems:
Newson Gale Earth-Rite® II PLUS can measure the loop from the clamp teeth to the verified ground point with accuracy below 10 ohms. The system meets all relevant standards.
Limitations of simpler systems:
Some competing solutions measure up to 35,000 ohms and do not meet any of the applicable standards. They may also incorrectly indicate proper grounding if the clamp is connected to, for example, a railing or tool, which can lead to hazardous situations

Impedance-Based Grounding Systems

These systems use electrical impedance (Z) as a parameter. Impedance is a combination of resistance and reactance (capacitive and inductive), and is strongly influenced by cable length and environmental conditions.

They provide visual indication and interlocking, but do not continuously monitor that the resistance between the clamp teeth and verified ground is <10 ohms.
They generally do not meet international standards and recommended practices.

Capacitance-Based Grounding Systems

These systems identify the vehicle through its unique capacitance and then switch to continuous resistance monitoring.

They confirm connection to true ground (below 1,000 ohms) and ensure that the resistance in the grounding loop is <10 ohms.
They are fully compliant with IEC TS 60079-32-1, NFPA 77, and API RP 2003.
They require no calibration or site adjustment—they work “out of the box.”

Important Safety Procedures

Always Ground First!
Attach the ground clamp to the vehicle before any other action is initiated—such as connecting hoses, moving the loading arm, or stabilizing the trailer. Wait for a GREEN flashing LED indication showing that proper grounding is established.

Always Use a Capacitance-Based System
To meet all safety requirements and avoid operational disruptions, it is best to use a capacitance-based grounding system that monitors the connection continuously and automatically.

Selected products

Earth Rite RTS

Explosion-protected grounding system with tank truck identification and monitoring of ground clamp and grounding circuit.

Earth Rite DGS

Explosion-protected grounding system with the ability to monitor two units together or in parallel, and interlocking of, for example, pump(s) can be adapted accordingly.

Ground Clamp X90 IP

Stainless steel ground clamp for dissipating static electricity in hazardous environments. With Quick Connect coupling.

Spiral Cable 2-Conductor

Blue spiral cable in various lengths that retracts after use.