_Yacht Surveyor
Gas Installations on Yachts
After Gas Explosion
  Gas is probably the highest risk of injury/death or at least serious damage to the yacht. Yet installations are often not taken seriously enough by owners or crew. Making the system compliant can often cost a small amount of money.  
  Lets look at some actual installations :  
Bottle is not secured, hose is tight. A dangerous installation on a large sailing yacht. Multiple sources of ignition also present in this lazarette. No gas drain.
Motor Boat flybridge locker. Bottle is not secured, multiple electrical sources of ignition present. No gas drain.
High pressure hose, part of a dual bottle installation with heavily corroded end fitting, this should be replaced. Bottle in a poor condition with corrosion as coatings not maintained.
Flexible Rubber Oil Hose - Not Suitable, especially because butane and propane will attack rubber
Air Hose - Not Suitable. Hose not secured to regulator barbed fitting with stainless clip. Locker should have bulkhead fittings, holes render locker not gas tight to height of regulator. Flexible hose connection to copper piping should not be outside locker.
Second bottle sits over gas drain rendering it useless. Locker material of wood does not have enough fire resistance
Hose secured to copper piping without proper barbed hose fitting. This connection should anyway be inside the gas locker and best by a bulkhead fitting at the gas locker
Proper bulkhead fitting in the gas locker of a modern yacht which connects the flexible hose to copper piping
Previously RCD compliant gas locker installation with hose made to unknown standard
Flexible Gas Hose deterioration seen when bending it. To be replaced.
21 Year Old Gas Hose. Should be replaced every 5 years
In French "Replace Before 2002" 8 Year old gas hose
Gas Drain Skin Fitting unusually is a hose barbed fitting. Completely inappropriate as it does not meet the minimum 19mm diameter required for a proper gas drain.
Regulator with plastic hose barb which sheared off completely during inspection. Unsuitable
  Basic Principles of LPG Gas Safety  
  Gas Drain - LPG is heavier than air and it is a searching gas. Any leakage will seek out the lowest point of any enclosed area. The main principle is to have the bottles and regulators in a gas locker which is designed with a drain at the lowest point so that the gas drains overboard and not into the interior of the vessel.  
  Avoidance of Leakage - The system should be without leaks, maintained in a good condition by following good practices and replacing deteriorated components. The system should be installed to approved standards and any alterations to the system must also be done to approved standards and not introduce problems.  
  Secured Against Damage - The bottles, regulators, piping must be located and secured so they cannot be damaged by items falling on or against them.  
  Some Basic Requirements for a Safe Installation  
  Cylinder Locker  
  All cylinders must be stored upright and secured from movement, in a locker which is gas tight to the hull interior at least to the height of the regulators.  
  The locker must be with a drain at the lowest point that leads overboard above the waterline. The drain should have a diameter of 19mm.  
  The locker must be ventilated at a height above the cylinders/regulators.  
  The locker must not contain items that could damage the bottle or block the drain  
  The locker should have a fire resistance of 30mins. This is to provide a good chance to fight a fire on board without the bottles exploding too. Therefore it should be constructed of metal at least 0.9mm thick with welded or brazed joints OR the locker can be of fibre reinforced plastics with minimum thickness 5mm.  
  Flexible Hoses  
  Flexible Hoses should be kept to a minimum length, no longer than 1m. High pressure hoses should be of pre-assembled type with the fittings already on them.  
  Flexible Hoses must meet a suitable gas standard. See below.  
  Flexible Hoses must be connected to terminals with proper hose barbs and be secured with a stainless clip. Direct connection to copper piping with no hose fitting is not permitted.  
  Flexible Hoses and Pipework must be away from items which may fall against it.  
  Installation pipework should be without joins if it passes through the engine compartment.  
  Installation pipework should be solid drawn copper joined with compression fittings rather than soldering or brazing. The number of joins should be minimised. The pipework should be properly supported along its length (at positions no more than 500mm apart) and be located as high as practicable. Not in the bilges.  
  Flame Supervision Devices  
  Burners, ignition burners and pilot lights must have flame supervision devices so that the gas supply is cut off if the flame goes out.  
  Isolation Valves  
  Each appliance should have it's own isolation valve. The valve locations should be clearly marked and also with open and close positions marked next to the valve.  
  Main shut off valve(s) must be located as close to the cylinder as possible and not in the accommodation.  
  LPG Appliances such as Water Heaters  
  LPG Appliances such as water heaters should be of room sealed type otherwise they are not recommended. This means that their air inlet and exhaust goes to outside the vessel not in the compartment. This is particularly important in small spaces like the heads or a shower compartment.  
  Bubble Tester  
  It is recommended to install a bubble tester so that the owner can personally check the system for leaks.  
  Further Information  
  The UK Inland waters BSS scheme is a sensible standard to apply to gas installations and it is suggested that yacht owners are familiar with Chapter 7 of this (download here) and also the LPG section in the appendicies (download here)  
  Further information can also be found at Calor Marine Shop  
  Appendix - Standards  
European Standard British Standard


EN 1763-1:2001 Class A BS3212:1991 Type 1. Flexible Hose Black Low Pressure Applications
EN 1763-1:2001 Class B BS3212:1991 Type 2. Flexible Hose Orange

High Pressure Applications. Preferred for all marine LPG Flexible Hose applications. Length to not exceed 1m.

EN 1763-1:2001 Class B BS3212:1991 Type 2 . Flexible Armoured hose Metal exterior For connections to gimballed or portable cookers
EN 1763-1:2001 Class B

BS3212:1991 Type 2. Flexible Pre-assembled hose

Black For high pressure connections, hoses of no more than 1m length pre-assembled with connections are the ones which are permitted
  BS669:1995 Part 1 Black with Red Band Cooker connections
ISO 2928:1986 Flexible Hose   Required standard for Recreational Craft Directive, or Equivalent
European Standard British Standard   Usage
EN 12864:2001 Annex M BS EN 1949:2002   Annex M is for Marine Environment. Required standard for Recreational Craft Directive, or Equivalent
EN 13786     Automatic Changeover Regulators. Required standard for Recreational Craft Directive, or Equivalent
Item Replacement Times
Regulators Recommended 10 years or before if deteriorated
Flexible Hoses Recommended 5 years or before if deteriorated. This is from date of manufacture not installation date. The date is written on the hose.
Armoured Hose When armouring externally corroded.
Copper Pipework When deteriorated, corroded.
Stainless clips When corroded (If corroded then likely a poor quality stainless)
Bottles When deteriorated or damaged. Should be kept properly painted to avoid corrosion.
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