Commercial Pressure Vessels

CNG Cylinders

Lightweight Type III composite cylinders for compressed natural gas storage in automotive, industrial-vehicle and mobile applications.

Steelhead CNG cylinders combine 6061-T6 aluminum liners with composite reinforcement to reduce system weight while providing robust, gas-tight high-pressure storage at 3,600 PSI.

Steelhead Type III CNG cylinders with integrated valves

High-pressure CNG storage

Lightweight cylinders for demanding on-vehicle applications.

Steelhead's Type III CNG cylinders are designed for systems where vehicle weight, packaging, durability and certified high-pressure storage performance are critical.

The CNG portfolio includes Nomad Series — Nomad Tide for compact installations, Transit Series — Liberty in the 11-inch platform, and Transit Series — Freedom in the 16-inch platform.

3,600 PSI

250 bar operating pressure for certified CNG storage.

Type III

Metallic liner with full composite overwrap.

FMVSS 304 + NGV2:2023

Current CNG product-family certifications.

CNG product families

Three CNG platforms for different vehicle and storage envelopes.

Steelhead's CNG portfolio includes compact and high-capacity Type III platforms for vehicle, vessel, fleet and specialty compressed-natural-gas applications.

Steelhead Transit Series Liberty 11-inch OD 3600 PSI Type III CNG cylinder family

Transit Series

Liberty

11-Inch OD Type III CNG Cylinder

Lightweight on-vehicle CNG storage using Steelhead's 280 mm (11 in) diameter Type III platform.

  • 30–120 L documented water-volume range
  • 250 bar / 3,600 PSI operating pressure
  • 280 mm / 11 in outside diameter
  • Dual 1-1/8-12 ports
  • Strap mounting
  • Lyra and Oasis valve options

View Transit Liberty →

Steelhead Transit Series Freedom 16-inch OD Type III CNG cylinder with valve assembly

Transit Series

Freedom

16-Inch OD Type III CNG Cylinder

High-capacity CNG storage for transit, commercial-vehicle and fleet applications requiring larger onboard fuel volumes.

  • 90–270 L water-volume range
  • 250 bar / 3,600 PSI operating pressure
  • 414 mm / 16.3 in outside diameter
  • Dual 1-1/8-12 ports
  • Strap mounting
  • NGV2:2023 & DOT FMVSS 304

View Transit Freedom →

Steelhead Nomad Series Nomad Tide compact 6.8-inch OD Type III CNG cylinder

Nomad Series

Nomad Tide

Compact 6.8-Inch OD CNG Cylinder

Compact Type III CNG platform for vehicle and vessel installations where available space and system weight are tightly constrained.

  • 8 L and 10 L standard configurations
  • 6.8 in / 172.7 mm outside diameter
  • 3,600 PSI CNG family
  • Sherwood CNG valve + plugged second port

View Nomad Tide →

Transit Series — Liberty

Liberty: 30 to 120 liters on a common 11-inch platform.

Transit Series Liberty uses Steelhead's 280 mm (11 in) diameter Type III platform for lightweight high-pressure CNG storage in automotive, transit and industrial vehicle systems.

Volume Range 30–120 L
Outside Diameter 280 mm / 11 in
Operating Pressure 250 bar / 3,600 PSI
Mounting Strap
CNG cylinder valve and pressure-relief hardware

Transit Series — Freedom

Freedom: high-capacity 16-inch Type III CNG storage.

Transit Series Freedom is Steelhead's 16-inch OD Type III CNG platform for transit, commercial-vehicle and fleet applications requiring larger onboard storage volumes.

Water Volume Range 90–270 L
Outside Diameter 414 mm / 16.3 in
Operating Pressure 250 bar / 3,600 PSI
Mounting Strap
  • Dual 1-1/8-12 ports
  • OMB Lyra CV CNG Valve and PRD, Oasis, and VTI TPRD options; inquire for others
  • NGV2:2023 & DOT FMVSS 304 certifications
  • Custom lengths available by inquiry
Steelhead Transit Series Freedom 16-inch OD Type III CNG cylinder with integrated valve assembly
Water VolumeMass (lbs)Mass (kg)OAL (in) without valveOAL (mm) without valve
205 Liter203447822090
270 Liter2926421022578

Nomad Series — Nomad Tide

Nomad Tide: two compact configurations for constrained installations.

Nomad Tide is the compact 6.8-inch OD CNG platform, available in 8-liter and 10-liter configurations.

Nominal VolumeLength Without ValveLength With ValveMass Without ValveOutside Diameter
8 L (2.1 gal)652 mm (25.6 in)704 mm (27.7 in)8.5 kg (18.7 lb)172.7 mm (6.8 in)
10 L (2.6 gal)741 mm (29.1 in)792 mm (31.2 in)9.0 kg (20.0 lb)172.7 mm (6.8 in)

CNG cylinder technology

Type III composite cylinder architecture.

Lightweight construction without compromising high-pressure gas containment.

Across Transit Liberty, Transit Freedom and Nomad Tide, Steelhead Type III CNG cylinders combine a metallic liner with composite reinforcement to reduce system weight while providing durable, gas-tight storage for demanding vehicle applications.

Metallic Liner

Provides the gas-retaining barrier at the core of the Type III vessel architecture.

Composite Reinforcement

Engineered composite overwrap carries structural loads while reducing vessel mass.

Engineered for Durability

Vessel architecture is designed around demanding high-pressure service, durability and vehicle integration requirements.

Cutaway diagram showing Steelhead composite pressure vessel construction, metallic liner, composite reinforcement and vessel design features
Steelhead composite pressure vessel construction and design features.

Construction & safety

Built for safe, gas-tight CNG storage in demanding environments.

6061-T6 Aluminum Liner

Metallic liner provides the gas-retaining barrier in the Type III construction.

Composite Overwrap

Full composite reinforcement reduces weight compared with conventional all-metal CNG cylinders.

Thermal Pressure Relief

CNG valve configurations incorporate thermally activated pressure-relief capability.

  • FMVSS 304
  • NGV2:2023
  • Type III
  • 3,600 PSI
  • CNG

Applications

CNG storage for vehicles, transit fleets and mobile systems.

Steelhead CNG cylinders can be integrated as a single vessel or as part of a bundled on-vehicle storage system.

Industrial airport vehicle illustrating an on-vehicle compressed natural gas storage application
CNG cylinder systems can be packaged into mobile and specialty-vehicle platforms where available space, capacity and system integration must be considered together.

Commercial Vehicles

CNG storage for fleet and commercial vehicle applications.

Transit & Industrial Vehicles

High-pressure CNG storage for transit, industrial and specialty-vehicle platforms.

Compact Mobile Systems

6.8-inch OD storage where packaging space is especially limited.

Vehicle / Vessel Integration

Compact CNG configurations can support vehicle or vessel gas-storage installations.

Engineering support

Configure CNG storage around the vehicle.

Steelhead can help evaluate storage volume, cylinder diameter, port configuration, mounting and system packaging for CNG applications.

Volume Selection

Match storage capacity to vehicle range and available installation space.

Valve Integration

Review valve, plug and pressure-relief-device requirements.

Mounting & Packaging

Evaluate single-cylinder or bundled layouts and strap-mount integration.

Nomad Tide 6.8-inch OD, 8 L and 10 L compact configurations.
Transit Liberty 11-inch OD, 30–120 L documented volume range.
Transit Freedom 16-inch OD, 90–270 L water-volume range; custom lengths available by inquiry.

Talk to a pressure vessel expert

Which CNG cylinder platform fits your vehicle?

Share your required capacity, installation envelope, valve and mounting requirements with Steelhead.

Talk with an Engineer