14
3 Assembly
4 Hydrogen connection
3.3.2 SPM cooling fans
The two mounting brackets are included to aid the creation of an air gap. This is
required to allow up to a 20m
3
/min of airflow through the FCPM. It is important
to have an even airflow distribution to both SPMs allowing the system to work
efficiently, if the air is being recirculated a minimum of 1m
3
/min of supplemental
oxygen is required.
4.1 Connector specification
The hydrogen is supplied to each SPM via 6mm OD x 4mm ID push fit tube.
A hydrogen compatible material with anti-static and low hydrogen permeability
is required.
Recommended tubing: 6mm OD x 4mm ID, anti-static, polyurethane
SMC TAU0604B-20
4.2 Hydrogen specification
When installing and operating hydrogen systems, hydrogen general safety guidance
should be considered:
ISO/TR 15916 – basic considerations for the safety of hydrogen systems for more
detailed information.
The hydrogen purity should comply with the specification in the table below:
Fuel Characteristics
Fuel Requirements
Hydrogen concentration
> 99.90%
Nitrogen, Helium, Argon
< 0.10%
Oxygen
< 50ppm
Carbon Dioxide
< 2ppm
Carbon Monoxide
< 0.2ppm
Ammonia
< 0.1ppm
Sulphur containing compounds
< 4ppb
Max particle concentration
< 1mg/kg
Max particle diameter
< 75µm
