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703-4 series 

Hydrogen fuel systems

350 bar & 700 bar 

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General info

703 Series - Pressure regulator for Hydrogen fuel systems


The 703-4 is a large capacity version of our 703-3 regulator, it has a higher flow capacity and can be set to higher outlet pressures. 

Designed to be simple and lightweight - H2 Technology’s 703 series Hydrogen Pressure regulator has been specifically designed for use with Hydrogen fuel systems

Fully certified to EC79, it is suitable for use in a wide range of Hydrogen fuel applications, including: Fuel cell vehicles, ICE Conversions, pure Hydrogen fuel systems and more.  

Currently in service in a variety of applications, such as: Cars, Buses, light commercial vehicles, boats, and off highway equipment such as excavators, tractors and generator sets.

The 703 series pressure regulator was designed without integral filtration, gauge ports or outlet pressure adjustment.  Our philosophy is to keep the regulator design as simple and as possible, resulting in a compact and economic device with the minimum of moving parts, resulting in a reliable and durable device. 

With a proven performance in a wide range of applications, the 703 series Hydrogen pressure regulator offers a solution to many H2 fuel system applications.

Please contact our sales office for more information.

Features and benefits

- Suitable for 350 bar and 700 bar applications.

- Lightweight at only 1.2 Kg.

- Small size allows for mounting in pip run without the need for mounting brackets. 

- Rugged, reliable and proven design

- High flow rate configuration

Common applications

- Suitable for use with fuel cell systems, ICE conversions and pure Hydrogen fueled vehicles. 

- SS316L material ensure protection in all environments.

- Full EC79 certification - adheres to requirements of R134. 

Contact the office for more details.     

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Mounting details

Due to its light weight and small size, the 703 series does not require mounting brackets, instead it can simply be mounted in a pipe run as shown

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Product dimensions

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Due to the nature of the construction of the 703 series, we do not sell spares kits for this regulator. 

A factory service and overhaul service is available.  Please contact sales office with serial number for more information

Hover over the factory service option below to see the parts that are exchanged.

The predicted service life of a 703 series pressure regulator is 5 years or 150,000 miles whichever occurs first.

It is highly recommended that a full factory service be carried out on any regulators that have exceeded this service life.


A thorough visual inspection of the regulator should be carried out every 2 years, or 50,000 miles.


Please contact office if you require any additional information. 

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Factory service


Click the links below to download documents



Additional document downloads


Click on a link to download a file. 


Please contact office if you require any additional information.  

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703 series - Datasheet

703 series - 3D STP Model

PRESREG Valves product brochure

- Use tool to generate part number

- Contact sales office with part number for a price

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Ordering info

Use the tool below to generate a part number. 

Contact the sales office with part number for prices.

We are happy to offer assistance and advice on generating part numbers and advising the right regulator for the right application.  

Contact the sales office for more information.  Contact Us.

The following features are standard on all models:

-  Maximum inlet pressure:  875 bar

-  Factory set - fixed outlet pressure


The 703-4 series is currently in service with a large number of customers in a variety of applications, including: Cars, Buses, light commercial vehicles, boats, and off highway equipment such as excavators, tractors and generator sets.

See below a few examples of applications for which the 703 series has been used:


CMB.Tech are transforming a Ford F-Max truck into a diesel/hydrogen dual-fuel vehicle.

The high flow capacity of the 703-4 series regulator has been a perfect match for CMB for this application. 

find out more at:


CMB.TECH and Dutch full-service provider of power solutions DBR have partnered up to develop what is said to be the first dual-fuel hydrogen gensets for marine applications, aiming to accelerate the decarbonization of the maritime industry.

Again the high flow capacity combined with the light-weight, small profile and durable design of the 703-4 made it the perfect regulator for this application. 

Dual fuel technology has been integrated into the MK3.5 series without compromising on performance and retaining the reliability of a traditionally fueled vessel. It is the first vessel to truly offer a sustainable alternative to diesel fuel.

CMB.TECH was the first to build a hydrogen-powered passenger shuttle in 2017. Based on this proven technology, the Hydrocat 48 is now designed and built.

The base MAN engine is manufactured by MAN Engines for dual fuel use and retrofitted by CMB.TECH with a hydrogen injection system utilising H2 technology regulators within the fuel system, 


The world’s first digger, powered by a hydrogen combustion engine, will soon be on UK roads and building sites following recent government approval, helping to decarbonise the UK’s construction industry.

H2 technology worked closely with JCB to supply the regulators that were used for initial trails. 


Aberdeen City Council is reducing the carbon footprint of its fleet with the introduction of a new hydrogen dual-fuel road sweeper.

The Butcher Municipal vehicle has been converted by hydrogen fuel specialist ULEMCo and is able to use hydrogen in both the primary and auxiliary engines.

H2 technology has formed a close relationship with ULEMCo and supply the majority of regulators used on their conversions - helping to power a variety of vehicles in a number of different applications. 

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The GeoPura Hydrogen Power Unit (HPU) provides 250kVA of standard three-phase, 400V critical electrical power backed up by an integral 216kWh battery system and can effectively replace on-site diesel generators with an emissions-free alternative.

Two 703-3 regulators are used to control the gas pressure - supplied by H2 technology. 

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