High-pressure gas storage system CNrG®

Overview
The Heil CNrG® tailgate system is a rear-mounted CNG fuel-delivery solution that locates all tanks in the tailgate assembly to lower vehicle profile and move tanks away from the cab. The design eliminates roof-mounted tanks, reduces overall body height by approximately 12 inches, and preserves access to height-restricted areas.

Key benefits

• Enhanced safety by positioning CNG tanks at the rear of the vehicle, away from the driver compartment.
• Reduced overall vehicle height (~12 in.) versus top-of-body tank installations for improved access under low-clearance structures.
• Improved weight distribution: tanks at the tailgate shift load rearward and reduce front-axle load.
• Integrated tailgate design supports commercial fast-fill stations and extended range without split-system compromises.

Key components

• Integrated tailgate housing with modular tank configurations (multiple tank layouts available).
• Fuel Management Module (FMM) with digital, temperature-compensated gauge, enhanced diagnostics and telematics-ready capability.
• Per-tank pressure indicators in addition to the FMM display (can show pressures even if individual tank valves are closed).
• Valve-access covers: two-piece removable aluminum covers and tank valve plates secured with lynch pins for tool-free access.
• Curb-side defuel port on the tailgate for ground-level fuel removal during maintenance.
• CNG routing uses increased stainless-steel tubing and fewer hoses; all lines individually clamped and protected against abrasion.
• Protective covers on CNG tubing and fire-sleeve insulation on hoses and coolant lines between engine and regulator.
• Retrofit/upgrade kits available to increase tank capacity (upgrade from three up to six tanks on DuraPack/LowRider bodies and up to seven tanks on Half/Pack bodies).

Applications & compatibility

• Designed for Heil DuraPack® style bodies including Half/Pack® and LowRider® low-profile bodies.
• Offered as OEM-installed CNrG tailgate or as tailgate assemblies and tank add-on kits for remounting bodies to CNG chassis.
• Long-range configurations supported: up to 90 DGE in six-tank layouts (DuraPack) and up to 105 DGE in seven-tank layouts (Half/Pack), application-dependent.

Safety & compliance

• System components and assemblies meet current CNG safety standards, including NGV2 2021, NFPA 52-2023, and FMVSS 304.
• Design validated through stress analysis and program-level durability testing prior to release.

Resources & media
Product media includes photography, illustrated brochure and videos demonstrating the FMM digital gauge, defuel port location, reduced overall height and weight-distribution benefits.

Technical specifications

• Model family: CNrG® tailgate system (rear-mounted tank assembly).
• Tank configurations: up to six tanks for DuraPack/LowRider bodies and up to seven tanks for Half/Pack bodies, dependent on body/chassis.
• Fuel capacity examples: up to 90 DGE (six-tank) and up to 105 DGE (seven-tank), application-dependent.
• Height reduction: approximately 12 inches lower overall body height versus top-of-body installations.
• Fuel Management Module: digital, temperature-compensated gauge; enhanced diagnostics; telematics-ready.
• Per-tank monitoring: individual tank gauges plus FMM monitoring (displays pressure even if tank valves are closed).
• Defuel port: curb-side tailgate access for ground-level defueling.
• Materials & routing: increased stainless-steel tubing, reduced hose count, individually clamped lines, protective tube covers, fire-sleeve on hoses.
• Access & maintenance: two-piece removable aluminum covers; valve-cover plates with lynch pins (no special tools required).
• Retrofit capability: modular upgrade kits, tailgate assemblies and tank add-on kits for existing bodies.
• Standards & certifications: NGV2 2021, NFPA 52-2023, FMVSS 304.