Before I begin, it’s important to note I am not a Gas Safe engineer, I am, in fact, an IT manager. Any information you take and employ from the below is your own responsibility. Any work you undertake on your boat, get tested professionally and take any advice they give you.
Gas is explosive, I mean gas is REALLY, really explosive. I see it as the one most dangerous thing on board Triola (apart from the ships dog perhaps). Not only can it blow your boat, crew and ships dog sky high (as ably demonstrated by Yachting Monthly below), but once it is burnt it gives off deadly, odourless CO (Carbon Monoxide) that can kill your entire family whilst they sleep (see the the BSS guide to this for more information).
Bear all of this in mind before considering to undertake the fitting out of the gas on board your beloved vessel, and understand that a bodged job could be fatal.
Warnings aside, I like to understand every system on board my boat so that if I have some form of problem at sea, I know where to look and have a good idea how to resolve the problem, so I was keen to undertake the job myself with no prior experience of fitting gas. I was shocked to find most useful information has been pulled from industry body websites, presumably on the grounds of ‘elf and safety and that potential we have seen above for blowing ones self to kingdom come. Some brave bastions, however, still do publish useful information, as you can see below:
Additionally, below is a useful cut out guide from an old Practical Boat Owner on the fundamentals of a good on board gas system.
So, in practise, how did I apply these fit out guides and the cracking assistance I had on YBWs forums to Triola.
1.0 Research, Plan and draw up a shopping list
Triola had old, perished, rubber hose going directly to the cooker from the gas locker – not ideal. The gas locker is in the Starboard locker, aft of the galley, and I had fitted our new wizzy Propex heater on the port side of the boat under the deck (the ducting run would be easier on that side of the boat). The only accepted method of moving gas that distance around the boat is copper pipe and compression joints.
A compression joint is made up of a brass joint, a copper pipe, and a copper olive. As the brass compression joint is tightened, it ‘squashes’ the copper olive onto the copper pipe making a gas tight seal. On my boat I chose to use 5/16 inch copper pipe, which should carry enough gas for both the heater and cooker – its important to choose pipe wide enough for your application, also, the wider the pipe, the thicker the walls and thus the safer it is. 8mm and 5/16 inchs are very similar in size, some suppliers (BES for instance) use the same part number for 8mm and 5/16ths fittings.
1.11 How to make up a compression joint
To successfully make a gas tight compression joint is not rocket science and if fitted right will not require any jointing compound (in fact if you use jointing compound or PTFE tape your joint stands a better chance of failing). In fitting gas in your boat ONLY use copper olives, NOT brass olives as these are too hard and will crush the copper pipe too much and not make a gas tight seal. What is an olive I hear you cry? (we are not talking the character out of Popeye here) An olive is a small ring of copper that is ‘crushed’ onto the copper pipe by the compression joint to make the gas tight seal. Bear in mind that gas molecules are smaller than air molecules, so are that much harder to contain. So what is the process:
- Step 1 – Take one end off your compression joint (in this case I am fitting a valve which has compression fittings both ends). Normally, compression joints are sent out with an olive in them, as you remove the end from your compression joint, the olive will fall out (make sure its a copper olive at this stage, if its colour matches the pipe, you are okay to proceed). Put the end you have taken off the compression joint over your pipe, and then slip the copper olive onto the gas pipe.
- Step 2 – Push the pipe into the body of the compression joint as far as it will go and then push the ‘nut’ up to the compression joint body (which in turn will slide the olive up to it) and tighten hand tight.
- Step 3 – On 5/16ths (or 8mm) pipe the rule is ‘hand tight’ plus a turn and a half (1.5 turns). The body of a compression joint will normally have two flat sides that you can hold with a spanner. Then grasp the nut with a well fitted spanner, and turn half a turn at a time (or quarter if access is a problem) until you have achieved the required tightness.
I made up a bunch of compression joints in my garage before I got anywhere near the boat, practise makes perfect and all that. The olive inside your compression joint will be squashed onto the pipe as below (one I cut off where I had made a pipe to an incorrect length).
If you make up a compression joint in the wrong place, or are just not happy with how its gone, just undo the compression joint, chop that bit of pipe off, add another olive and remake the joint.
1.12 How to cut copper pipe
Do yourself a favour, don’t even consider using a hacksaw to cut your copper pipe. You will end up with wonky cuts full of burrs and it’s tiring, and unpleasant to boot. A pipe cutter is an awesome little tool that will make clean cuts easily, quickly, and cheaply. You can pick them up from screwfix for pennies.
The old adage is measure twice, cut once, and that applies here too, so make sure you have your lengths right before you start bending or cutting your copper.
The use the cutter place it around the pipe and make sure the pipe is lined up with the cams and do it up so it just touches the pipe. Do not over tighten it at this point as it will distort the pipe!
Turn the pipe cutter around the pipe a few revolutions, you will see it scoring the pipe, tighten it a little, and turn a few more revolutions. Repeat until your pipe falls in two. You may still have some burrs, use a metal file to remove those burrs making sure you remove all copper dust when you are done.
1.13 How to bend copper pipe
When you get your copper pipe it will be annealed, which, through metallurgical wizardry, means it is easier to bend when you get it. Once you start working with your copper though, the clock is ticking, the more you work it, the harder it gets (until it becomes ‘work hardened’). In order to create professional, 90 degree bends, you will need a pipe bender else you will distort the pipe. These are available very cheaply from your local Screwfix.
Open up your pipe bender fully and place the pipe into the groove for your pipe. The below pipe bender does 6mm, 8mm (so our 5/16ths then) and 10mm, so we need to make sure it is in the 8mm slot squarely. Bring the arm down carefully onto the pipe lining up the two 0’s
Gently bend your pipe to the desired angle (all my bends were 90 degrees or there abouts).
The gas had to somehow travel under my cockpit, up a bulkhead and under my deck to the Propex unit, whilst also travelling forward to my galley. I wanted as few joints as possible (less joints to potentially leak). I also wanted to build in safety from the word go so wanted to include a bubble tester (as seen in the PBO information cut-out above) and a test point that could be used by a professional to test the system once I was done. Using Microsoft Visio, I settled for the below design:
The V meaning Value so I could isolate each appliance, the H standing for barbed hose tail fitting, the T standing for a T-piece compression fitting, and the B standing for a Bubble tester.
1.3 Shopping list
ASAPs are a cracking outfit that you will be able to buy all your compression joints, olives, pipe, bubble testers and other consumables. For tools, however, they do not stock much, so you will likely, like me, need to shop around for what you need – I found lots of useful stuff at Hamiltons gas products.
- A good set of spanners
- A pipe bender
- A pipe cutter
- A drill with a small drill bit for making pilot holes
- Potentially a jigsaw (we’ll come to why later) or other means of chopping up plywood.
- Leak detection fluid – Yes, you do need special stuff for this as it was found that washing up liquid and water could actually corrode the fitting!
- A gas ‘sniffer’/hand held detector – Safety first and I figured it would be a very useful gadget on board if a leak ever came about as well.
- Gas jointing compound – This is ONLY for joints which are sealed by a thread alone, such as the tapered joint into the Propex unit. It should never be used on a compression joint, the mechanical seal should be enough. If at sea you get a leak in a compression joint that can’t be cured by ‘tweaking’ the joint, then it can be used as a stop gap, but never as an enduring solution.
1.32 Consumables (for my specific job, yours will vary of course)
- 5/16s Copper pipe – You will need more of this than you think as you will cock up during the learning process (a lot).
- 1 x T piece compression joint
- 1 x Elbow compression joint
- 2 bags of five olives (just in case I needed to remake compression joints)
- 2 x valves
- 1 x hose tail compression joint
- 1 x bubble tester
- 1 x test point
- Some P clips to hold the pipe. I used plastic ones, you can use rubber lined metal ones if you are worried about engine vibration.
- Screws to fix the P clips to bulkheads.
- Some spacers to stand the p clips off bulkheads around fittings.
- Some scrap marine ply (potentially).
- WEST SYSTEM epoxy (potentially) or some other means to glue plywood to the hull.
1.33 On-board systems
- A gas alarm with a remote sensor in the bilges (gas is heavier than air so will naturally sink and gather in your bilges) is a must. I went for the NASA alarm. Ideally this should have an automatic switch off solenoid. On Triola we always shut the gas off when we are not using it so the alarm was fine for us.
- A CO alarm. It cannot be stressed enough how important a working CO alarm is. CO is actually lighter than air, and thus will gather at the top of your saloon, thus any alarm you fit must be high up. I went for an alarm which had a display that would tell me exactly how much CO was in the air at any one time, with a seven year battery life (so not wired into the 12V system at all).
Once you have your box of exciting plunder and unfathomable tools, get back to your garage/shed/bat cave and practise cutting, deburring and making up compression joints and then taking them apart again and making sure the look good.
2.0 – Commence fitout!
I decided to begin at the source and work outwards to the appliances on the fitout so began with fitting the bubble tester. Ideally, the bubble tester should be fitted inside the gas locker with a very short run going to the gas cylinders, in my case that was not practical as my gas locker only just has space for the two cylinders in it, so I attached it to a bulkhead just forward of the gas locker and by a short run of flexible gas pipe. From there, I ran a copper elbow down to the T piece.
The bubble tester is the only point where I used a brass compression fitting as per Aldes instructions. They supply a brace to insert into the copper tube to support it as the compression fitting tightens down. On the left side of the bubble tester I put the hose tail where the gas inlet would be attached. The bubble tester was fixed to the bulkhead behind the galley.
From there, the starboard end of the T piece would travel out to the hull, along the hull, and then back in to a shut off valve and a hose tail to go to the cooker. Note, in the below, in order to fit the pipe, I needed to cut the aft 90 degree angle off and add an elbow joint where I have marked it.
Note that the pipe is supported at every 150mm and more around bends and joints. Where the pipe runs along the hull or insides of the single skinned cockpit, I cut plywood shims that I could epoxy on to support the pipes.
These shims support the gas pipe as it travels forward underneath the cupboards and behind where the fridge box will be fitted.
Note that the copper passes through two bulkheads here. The Boat Safety Scheme suggests using bulkhead compression fittings when moving copper through bulkheads, however, this only really refers to water tight bulkheads, and these two are merely galley furniture bulkheads and are not glassed in. I applied my mantra that fewer compression joints equalled fewer places to leak! The thing to watch out for here is any point where chafe could occur and make sure the copper pipe is not making any contact with the bulkhead it is passing through.
Going to port from the T piece, under the cockpit, and all the way up to under the deck to reach the Propex heater unit was always going to be the most challenging run. I planned out this three dimensional run carefully on paper (why does every job on a boat involve being wedged, upside down, in a cockpit locker), making sure I measured each section out carefully before going and creating this complicated and long run of copper pipe. The resultant piece came out as below:
The end you are seeing on the far left of the image above is the bit that ends up at the Propex heater. On the bottom right of the image we can see the end that will pass under the cockpit to connect with our T-piece on the starboard side.
From there the pipe travels straight under the cockpit:
And then up and around the bulkhead at the other end, passing up under the deck.
The end of this then travellings under the deck and finally connects to the Propex unit and a stop valve. The gas fitting into the Propex unit is a tapered thread, so use some jointing compound here to seal the threads. A final elbow of bent copper was required to get the gas all the way to the unit. My shims here were not quite big enough to support the pipe, so these will be augmented at a later date.
3.0 – Worry, test, worry, test again
Seeing boats blowing up does focus the mind somewhat. I geared up by finishing the NASA gas alarm install, putting the batteries in my Honeywell gas detector wand, and spraying all the joints in my fit out liberally with leak testing fluid.
I put the regulator on the gas bottle, and didn’t turn it on. I depressed my bubble tester and was alarmed to see bubbles coming out! I scoured the Alde literature, and that said nothing about it. I reasoned there must be air in the system and to try turning the regulator on, both isolator valves off and let gas into the system. At that point I tested the bubble tester again, to my relief, no bubbles showed. Regardless, I leapt about with my gas testing wand and tested all joints.
To my shock, I found no leaks anywhere. Biting the bullet, I turned the gas valve on to the Propex, checked for leaks again, and then turned the heater on. After two or three purges, the heater fired up and once it had got going warm air flooded into the saloon. A job well done! Now finally to get the professional gas professionals in to pressure test the whole set up.
Finally, once again, I am not a Gas Safe engineer, I am an IT manager. Any information you take and employ from the above is your own responsibility. Any work you undertake on your boat, get tested professionally and take any advice they give you.