Truma Rupture Hose

[sandalwood]

Has anyone had the above fitted on their Motorhome? Experiences please, how does it work. Is it safe!

 

Taylor

[Derek Uzzell]

An example of a Truma 'Drive Safe' rupture-protection hose is shown in this advert

 

https://shop.caravanclub.co.uk/product/1030216/propane-hose-450mm-uk-with-rupture-protection

 

Drive Safe hoses are marketed with several different end-fittings and in different lengths. The hose is intended to be fitted between a gas-bottle's outlet and a bulkhead-mounted Truma Drive Safe gas regulator. When the bottle's gas has been turned on (say after an empty bottle has been replaced) the green button on the hose needs to be pressed in to allow gas to flow from the bottle to the regulator. If the hose subsequently develops a serious leak (eg. a road accident causes the hose to be ruptured) a valve in the end of the hose where it connects to the gas-bottle shuts off the gas flow to the regulator.

 

(I'm not sure how a Truma Drive Safe hose would be used when a motorhome has an underslung fixed LPG tank, nor how the hose might somehow be considered 'unsafe'.)

 

 

 

 

[weldted]

UnderSlung gas tanks are fitted with an automatic shut off valve in the event of a sudden loss of pressure, as against a steady flow during normal use

[Brian Kirby]

sandalwood - 2021-05-19 2:53 PM

Experiences please, how does it work. Is it safe!

Taylor

Have had these since 2007, and have experienced no problems. Fortunately, have never tested in anger!

 

Once the valve is set as Derek describes above, the pressure in the high pressure hose between cylinder and the regulator maintains the valve open. If anything causes a sudden drop in pressure, the valve immediately closes.

 

This can be experienced if, when first connecting a cylinder and turning on the gas, a gas cock to an appliance with a high flow requirement (cooker, hob, heater) is opened with only air in the system, when the sudden inflow via the regulator can be sufficient to trip the valve, so they are quite sensitive to pressure drop (when one simply re-sets the valve). However, once the gas lines to all appliances have been bled of air, I have never experienced the valve shutting supply in normal use.

 

The hoses were primarily intended for use in conjunction with Truma "Secumotion" (EU) or "Drivesafe" (UK, now "Monocontrol" - single cylinder - or Duocontrol - two cylinder, auto changeover) regulators which incorporate an impact sensing shut off valve, intended to isolate the gas supply into the van from the regulator, in an accident that does not result in a severed high pressure hose.

 

With the correct regulator plus the rupture protection high pressure hose both fitted, it becomes legal to drive in most of Europe with gas turned on at the cylinder (with the exception of ferries, the Channel tunnel, and certain long road tunnels.

[Derek Uzzell]

I’m guessing Sandalwood’s question is related to this earlier enquiry

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Truma-gas-electric-isolator-switch/58160/

 

There’s 2018 guidance on motorhome user-refillable LPG containers here

 

https://www.outandaboutlive.co.uk/motorhomes/articles/practical-advice/motorhome-advice-gas-tanks-or-refillable-cylinders

 

and (as Weldted has advised) any fixed LPG tank or user-refillable bottle that meets the R67 standard must have an excess-flow valve to protect against rupture of the hose that connects the tank/bottle to the gas regulator.

 

A Truma rupture-protection hose provides similar protection if a gas container (say a Calor bottle or pr-R67 Gaslow canister) has no excess-flow valve, but - in principle - would be superfluous for any gas container that already has an excess-flow valve.

 

For a fixed LPG tank it’s also questionable where/how the Truma hose would be installed. The hose has to go in the high-pressure side of the gas system (ie. ‘upstream’ of the regulator) but (as shown in the upper photo attached below) it’s commonplace for the regulator to be fitted directly on to the tank’s gas outlet. When the regulator is remote from the tank (lower attached photo) it might be practicable to install the Truma hose between the tank’s outlet and the regulator, but the green button on the Truma hose would really need to be readily accessible just in case the hose’s valve needed resetting.

 

(I’m pretty sure I’ve seen a photo of a motorhome’s fixed gas tank where a Truma ‘Crash Sensor’ regulator had been used, but I’ve never seen (or heard of) a Truma anti-rupture hose married to a fixed tank.)

 

To the best of my knowledge no European country has GENERAL regulations demanding that a leisure vehicle’s gas system be closed off when the vehicle is being driven. (It used to be widely claimed that France had such a rule, but this was incorrect.)

 

However, if Sandalwood is keen to have the gas-supply closed off when driving, fitting Truma’s electrically-operated gas shut-off solenoid valve is probably the best approach even though the tank’s gas outlet will still remain open.

 

[sandalwood]

Does that mean I can drive my IH TIO with the gas on please?

 

Ian

[Derek Uzzell]

Legally you can drive your motorhome with the gas outlet of its LPG tank NOT turned off, though (as Brian Kirby advised above) there will be occasions (eg. on ferries or using EuroTunnel) when the travel operator may demand that the gas supply is turned off.

 

There's also the legality (or otherwise) in some European countries of having a gas appliance (eg. a heater) operating in a moving vehicle, and that would depend on whether the vehicle's gas system has been designed and approved to allow that to be done safely and legally. It's doubtful that would be the case with your motorhome, but - as you wanted to turn off the gas before driving - it's plain that you only intend to operate gas appliances when your motorhome is stopped.