Gas
In the UK, LPG is available as propane or butane. The two types of LPG have slightly different properties. Butane has a lower operating pressure of 28 millibars but a higher calorific value and therefore a higher flame temperature. It is more commonly used in the UK as fuel for stoves on boats. Propane operates at a pressure of 37 millibars and works better in colder climates than butane. Operating pressures may be different elsewhere in the world.
Gas safety considerations
Gas is more dense than air, so in the case of a leak, it will make its way to the lowest point i.e. the bilges where it will stay until the boat is aired to clear it or something ignites it, which can result in a significant explosion.
Although LPG is potentially hazardous, it can be used quite safely if the equipment is properly installed, well maintained, regularly inspected for damage and used carefully.
Gas bottles
Gas bottles should be stored upright in a dedicated locker which drains overboard (to help prevent gas ending up in the bilges). The drain should be checked regularly for blockages, for example by squirting a hose pipe down the drain.
For boats which were not manufactured with a dedicated gas locker, finding appropriate stowage for the gas bottles can be difficult. The simplest option may be to secure the bottle on deck. However this needs to be done carefully to prevent accidental damage and should not be in a position which would allow leaking gas to enter the interior of the vessel i.e. located too close to hatches.
Most boats will also carry a spare cylinder which should be given the same consideration as the "in use" cylinder. Although the spare cylinder is less likely to leak, it is not impossible for it to do so especially if it is not securely positioned and protected from damage.
Gas pipe and hose
Pipes and hose should be regularly inspected for wear and tear. Gas hose is marked with the date of manufacture and has a life expectancy of 5 – 10 years, depending on the environment in is in. Don’t fit it and forget it!
Particular attention should be paid to vulnerable hose, such as where the cooker gimbals. The area behind the stove should be covered with a sheet of metal to prevent accidental damage to the vessel’s hull.
Gas safety devices
Flame supervision devices (which shut the gas off if the flame accidentally goes out) have been available since the early 1990s and are now routinely fitted to marine equipment. These have significantly improved gas safety on board.
Many boat owners now fit their boat with a gas alarm. The sensor for the alarm is positioned where gas is most likely to collect if there is a leak and the alarm goes off if it senses gas. Unfortunately, gas alarms have been prone to false alarms which all too often lead to the alarm sounding not being taken seriously – a bit like burnt toast setting off your home smoke alarm.
There are now modern gadgets available which can automatically shut off the gas when it is not in use and others which monitor the installation and indicate if there is a leak. A bubbler device, for example, is plumbed into the gas system and indicates the slightest leak, although as this is plumbed in directly downstream of the regulator, on many boats this may not be a particularly convenient location for regular inspection.
Using gas safely
Every boat should have a gas routine. What this is will depend on the design of the boat, the layout of its gas installation and the skipper. Ultimately, the safest option is for the gas to be turned off at the bottle whenever it is not in use and some skippers will ask that the flame is extinguished by turning the bottle off to ensure no gas remains in the pipe.
On many boats, the location and accessibility of the gas locker may make turning the gas off at the bottle an unattractive option. Many boats are fitted with a gas tap near the galley, which is often more accessible and many skippers opt to use this secondary tap. This option will prevent gas leaking if the stove (or other device supplied by the bottle) fails, but will not make a difference if the installation fails between the secondary shut off and the bottle. On some boats the gas may simply be left on and the cooker relied on to retain the gas, just as you do at home. The risk increases the further away from the bottle the gas is isolated.
Skippers are likely to take flame supervision devices and gas alarms (devices which sound if the sensor – which is located where gas is likely to accumulate in the event of a leak – e.g. the bilges) into consideration when setting the gas routine, which should take into consideration the weak points in the installation (i.e. where a leak is more likely e.g. joins and flexible hose). Everyone on board should know and follow the routine when using the gas.
In rough weather the gas should be turned off at the bottle and the bottle secured to ensure it cannot end up on its side or upside down which would allow gas to enter into the regulator at a dangerously high pressure; this could lead to taps leaking or dangerous flare-ups.
Should a gas leak be suspected:
- DO NOT SMOKE
- Shut the gas off at the bottle
- If in port, get everyone off the boat
- Lift the floor boards, open all the hatches and air the boat
It is commonly believed that manually pumping the bilges will clear gas. This alone will not dispel the gas, although it may help to create an air flow.
Never test to see if there is a gas leak with a naked flame, if there is a leak there is also a significant risk you will cause an explosion! An electrical spark will do the same, so do not operate lights or electrical equipment, including the electronic bilge pump, if a leak is suspected.
Installation and maintenance
The Recreational Craft Directive (RCD) specifies that LPG installations must conform to ISO standard 10239 LPG Gas Systems for all recreational craft of less than 24m LOA.
There is no requirement for private boat owners to maintain and repair their LPG system on a regular basis. If the vessel is operated on inland waterways and requires a Boat Safety Scheme (BSS) certificate it must additionally comply with the BSS requirements. This does not require that a Gas Safe Register engineer carries out the work as the BSS does not stipulate how this compliance is achieved.
For other private pleasure craft, where the BSS does not apply, there is still no general legal requirement in UK waters to have the gas installation fitted, repaired or inspected by a qualified engineer (unless there is someone living or working on board or local regulations may apply). A Gas Safe Register engineer will, however, know the correct materials and methods to use, to ensure that the work is completed safely.
The RYA strongly recommends that gas systems are checked regularly to ensure that any potential problems are spotted at the earliest opportunity. You may choose to do this yourself, looking for kinks or wear in the hose, making sure none of the clips are coming loose etc. or owners may opt to have their marine LPG installation inspected by a suitably qualified person, such as an engineer listed on the Gas Safe Register - as they do with gas boilers in the home. The gas industry recommendation for marine installations is for this to be done annually.
If you prefer to trust the trained eyes of a professional then at www.gassaferegister.co.uk a search based on postcode will help you to find the nearest registered engineer.
Replacing the regulator
A gas system that is not fitted with an EN 12864 annex m or an EN 16129 annex m approved gas regulator may not be compliant with bs en iso 10239 and therefore the vessel’s insurance could be invalid (see The Techy Bit below).
Propane cylinders contain considerably greater pressure than butane cylinders. Cylinder regulators designed for use with either propane or butane are not interchangeable because of different design pressures and the dissimilar cylinder valves for the two gases
If the regulator needs to be replaced it is important to make sure it is the right one for the cylinder it is being connecting it to. If necessary advice should be sought from a Gas Safe registered engineer.
New regulators should be clearly marked EN 16129. This standard has progressively replaced standard EN 12864; but regulators made to EN 12864 may be still available for sale. Anyone purchasing a new regulator should check that it is less than 3 years old from the date of manufacture. (See The Techy bit).
The Calor Gas Appliance Team have produced a video on how to change a gas regulator correctly and safely. The principles are the same for changing any low pressure regulator. The video shows you how to replace a 4.5kg screw on regulator with a clip-on 21mm regulator. Before changing a regulator, checks should be made to ensure that the operating pressure on the new regulator is the same as the old one. For butane this set to 28-30 mbar, a propane regulator is pre-set to 37mbar.
Refilling a rented gas cylinder
The refill adapters available on the internet may be tempting but a standard LPG cylinder is not fitted with overfill protection shut off which is an essential feature of approved refillable LPG bottles.
It is easy to find refill conversion kits and advice on how to refill a gas cylinder at kerbside fuel stations that supplies gas for refillable bottles fitted to vehicles and caravans. However, the refilling of rented gas cylinders in the UK contravenes UK Health and Safety Regulations, Weights and Measures Regulations and Consumer Safety legislation. It is illegal and anyone doing so could be prosecuted; it is also extremely dangerous. For safety reasons, refillable LPG cylinder systems are fitted with automatic 80% overfill protection when filling, rented cylinders do not have this.
The Calor refill agreement makes it clear that cylinders remain the property of the Company at all times and may only be filled by the Company. Calor has taken successful court action against individuals for unauthorised filling and is likely to continue to do so.
Alterations to the size of a gas locker to accommodate larger sizes of gas cylinder falls well beyond the scope of this guidance. Anyone considering this as an option should be advised to seek professional advice both from a boatyard and a Gas Safe registered engineer.
If you are switching to Campingaz from Propane then ensure your appliances are capable of running safely on Butane, if in doubt we recommend you consult a Gas Safe registered engineer.
Anyone considering refilling old cylinders should be reminded that it is illegal and dangerous.
The Techy Bit
The Rules
Since 16 June 1998, all recreational craft up to 24m in length placed on the market in the EU have had to conform with the essential requirements for their design and construction set out in the EU Recreational Craft Directive (RCD). The RCD was implemented in UK law as the Recreational Craft Regulations (RCR). The RCR have been amended to allow effective functioning now that the UK has left the EU. RCR currently sets out identical essential requirements to the RCD.
RCD/RCR state that where a [LPG] gas system is fitted for domestic use it shall be:
- Suitable for the stresses and exposures found in the marine environment.
- Of the vapour-withdrawal type.
- Designed and installed so as to avoid leaks and the risk of explosion
- Capable of being tested for leaks.
- Suitable for the specific gas used.
- Fitted with an enclosure to contain all gas cylinders, separated from the living quarters, accessible only from the outside and ventilated so that any escaping gas drains overboard.
- Tested after installation.
Regulation 41 of the RCR (Article 14 of the RCD) states that products that are in conformity with a standard designated by the Secretary of State (a harmonised standard in the EU) (or parts of such a standard) shall be presumed to be in conformity with the essential requirements covered by those standards or parts of those standards.
ISO 10239
This International Standard covers:
- The installation of permanently installed liquefied petroleum gas LPG systems and LPG burning appliances on recreational craft of up to 24 m length of hull.
- Pressure regulation devices (regulators) requirements including corrosion resistance.
- Storage of LPG cylinders.
ISO 10239 is a designated UK standard and a harmonised EU standard. LPG gas systems that are installed in accordance with ISO 10239 are presumed to be in conformity with the essential requirements for permanently installed LPG gas systems.
Section 5 of ISO 10239:2014 notes that pressure regulation devices in accordance with EN16129:2013, Annex M, meet the pressure regulation requirements set out in ISO 10239.
Section 5 of ISO 10239:2008 notes that pressure regulation devices in accordance with EN12864:2001, Annex M, meet the pressure regulation requirements set out in ISO 10239.
In order to ensure that a regulator is designed properly to meet the specifications of EN10239 section 5, a regulator certified to either EN12864 Annex M or EN16129 Annex M should be fitted. The standards can be verified from the data label that is fixed to the regulator.
EN 16129: 2013
EN 16129 defines the construction and operational characteristics, safety requirements test methods and marking for regulators. Additional test and marking requirements for seawater boats are set out in Annex M. A regulator that conforms to the requirements of EN 16129, Annex M will be marked with a reference to EN 16129 and include the marking “Marine”.
It should be noted that the publication of EN16129:2013 merged the requirements of the following three European standards covering the requirements for LPG regulators and replaced BS 3016, which has been withdrawn:
- EN12864: 2001+A3: 2009 Low pressure non-adjustable regulators
- EN13786: 2004+A1: 2008 Automatic changeover valves
- EN13785: 2005+A1: 2008 Regulators other than those covered by EN 12864
EN12864: 2001+A3: 2009 defines the structural and operational characteristics, safety requirements, test methods and marking of low pressure nonadjustable regulators for Butane and Propane (including their mixtures). Regulators covered by this standard are designed for a maximum outlet pressure of up to and including 200mbar and a maximum capacity of up to and including 4kg/h. The standard also covers regulators designed to be used in seawater boats. All though the standard has been superseded by EN 16129, it is still possible to find regulators marked with this standard (see buying a new regulator above).
EN13786: 2004+A1: 2008 deals with the construction and operational characteristics of automatic changeover devices that maintain the gas supply continuity by automatically using gas from a reserve cylinder(s) when the supply pressure from a service cylinder preselected by the user drops below a set value. These systems are not within the scope of this guidance note and are not considered further.
EN13785: 2005+A1: 2008 defines the construction and operation characteristics of regulators other than those covered by EN 12864 which covers regulators that are intended for seawater boats. As such it is not considered further.
Carbon monoxide
The silent killer carbon monoxide should not be forgotten or underestimated. Incomplete combustion of fossil fuels can produce carbon monoxide (CO). Appliance failure or damage, poor installation or lack of maintenance could all lead to bad combustion of the LPG, which coupled with poor ventilation can result in CO poisoning which may kill.
Regular inspection, together with a gas alarm, a CO detector and safe operation will significantly reduce the risks associated with having gas on board.
Further information
One of the largest suppliers of gas in the UK is Calor - useful advice is available on their web-site on the availability of gas supplies overseas and changing between propane and butane.