Typical practice for gaseous tube trailers is to vent relief devices independently to the top of the vehicle. This is primarily to accommodate the large flowrates and high thrust forces involved from these releases. It’s fairly easy to do this since the vent lines are fairly short due to the maximum road height of trailers. Regulations do not prohibit piping multiple devices into a
single header and this manifolding is an acceptable practice provided that the design is done properly. It is important to design the header sufficiently large to be capable of handling the combined flow of the devices. These devices are primarily for fire protection and it’s likely that many, or even all, of the vessels would be exposed to fire at the same time.

It is common for LH2 transports to have all the relief devices/bleed valves connected to one vent stack.

Many methods are used to mitigate the risk of a tube trailer hose loss of containment incident. Examples that otherwise exceed code requirements are provided below. These have been deployed in various combinations depending on the risk analysis for a particular system: 

1. Installation of automatic shutoff valves on the tube trailer upstream of the hose to activate upon hose rupture. These can be operated in two modes:
   1. Always open and activated only with a manual and/or automatic emergency shutdown system or 
   2. Always closed and only opened when in use, in addition to being closed via activation of an emergency shutdown system. 
2. Over-design of the hose with a higher factor of safety than the 3:1 otherwise required. Using a hose with a 4:1 factor, or even higher, is common. 
3. Implementation of hose replacement frequency as part of a mechanical integrity program. An interval of three years for a tube trailer hose is frequently used. 
4. Use of anti-whip restraints to anchor each end of the hose. 
5. Implementation of leak detection equipment, using either external gas detection or internal pressure monitoring systems. 
6. System design that prevents abrasion, kinking, or stretching of the hose when in service. 
7. Implementation of anti-pull-away systems for the trailer when connected to the station. 
8. Use of a self-sealing hose in the event of a hose rupture. 9. Use of a double-ended breakaway system similar to those used on fueling hoses.

A "drop and swap" delivery system using tube trailers is a common and accepted method of supply for both industrial and fueling station applications. While NFPA 2 - 2023, paragraph 10.6.3.5 states, "The use of hose in a hydrogen dispensing system shall be limited to vehicle fueling hose," this is intended for the dispenser itself, not the entire fueling station. This does not limit the use of a hose for other portions of the system where applicable. Examples where hoses are appropriate are tube trailer connections, compression equipment connections for vibration isolation, and purge connections. 

This requirement is under review by the NFPA 2 Technical Committees for clarification.