whilst im replacing an oven can i ......

[chubby]

Hello Folks

This summer my BSS is due . I fear my oven & hob have reached the end of thier usefulness having been fitted 18 years ago . So im looking to replace them . Though it is a " boaty " oven & therefore costly im leaning towards a model called " Thetford Spinflo Triplex " . A smaller oven , yes - but im ok with that . I currently have two gas pipes with cut off levers , one for hob & one for oven . The replacement oven requires only one connection . Is it feasable to use the redundant pipe & lever for fitting a Morco type water heater . 

Im not one for making assumptions so think it best to ask advice . Though i may fit the oven & morco as part of an overall refurb of the kitchen i will not be looking to connect the gas as i liveaboard & will seek to have a bod connect the gas- maybe even the BSS chap prior to the inspection itself . 

Thanks for any thoughts 

[Alan de Enfield]

3 minutes ago, chubby said:

Thanks for any thoughts 

Piping size is based on what appliances are connected to it (amount of gas needed)

Do you already have a Morco fitted ?

The gas pipe that currently runs your oven (and not your hob) will now be expected to run both your hob and your oven - is it the correct size ?

The gas pipe that did run your hob will now be expected to run the Morco - is it the correct size ?

If the Morco is an addition to the system, is your main supply pipe the correct size to run oven, hob and Morco ?

[BEngo]

It is feasible, but only if the gas pipe is big enough. The whole installation has to pass thr BSS flame test to ensure the gas pressure is OK at full load.  Ask your chosen gas bod.

N

 

[alan_fincher]

Yes, I agree with two answers already given.

A BSS tester needs to be able to have all appliances alight at the same time, and show there is not an unacceptable pressure drop, (even if you never do this in practice).

Required pipe sizings will depend on the actual appliances used, and how long the run is, so it is not possible to say i you will be OK, or not, without more info.

Generally I would say if it's a fairly long run from the cylinder, and your current feed pipe is only 3/8", it may well need an upgrade to 1/2" to be able to satisfy requirements for the extra appliance, (Morcos consume gas pretty quickly).  That's just a guide though - not a definive right answer for  your particular case.

[nicknorman]

Yes it’s all about pipe diameters and not having to much pressure drop at full load (all burners on). The other thing to bear in mind is that you can’t leave the second shut-off valve unconnected (for example, if you fitted the new oven but didn’t get around to fitting the water heater for a while). It mustn’t be possible to operate a tap/lever and have gas come out into the boat. So you need to properly cap off any unused outlet.

Edited January 30, 2018 by nicknorman

[chubby]

Thankyou for the replies

The morco would be a new appliance - there isn t one fitted already . The reason i ask is because the current set up has one pipe from gas locker running under the port side gunwhale . This pipe then Ts off and here are two yellow taps about 6 inches apart with flexible pipes . One each for hob & oven . 

The model of cooker im considering has ( i believe ) only one gas connection for the 3 hob burners & the combined oven / grill . Another model im considering is Voyager 4500 which also appears to have one gas connection . 

So rather than cap off the leftover gas tap , id prefer if feasable to use it to feed a Morco because all the kitchen worktop will be getting replaced & this is an ideal time to fit the morco . 

I will look at my boats info folder to see if there are more details about the existing pipework diameter .

Thanks again 

Having looked at my boats folder there is no info as to the main gas pipe diameter , it merely lists the whereabouts of the systems isolator valves . 

Would i therefore need to have a gas bod in to determine the size of the existing main pipework in order to assess whether its suitable for the extra gas a morco will need . If the pipework needed replacing then id not bother as it would be too costly - i am just seeking to utilise an existing connection that would be spare as the new oven needs only one pipe 

cheers

Edited January 30, 2018 by chubby

[nicknorman]

If you just measure the outside diameter of the pipe running from the gas locker to the T, folk on here will have a pretty good idea of whether it will be suitable or not. And there should be some info on the data plate of the oven as to its max gas usage or heat output. That combined with knowing the same about the proposed water heater, and the approximate overall pipe length is all that is needed.

[alan_fincher]

BSS regs require that the main feed pipe, (indeed all LPG pipe), is accessible for inspection, so very often they are just secured by regular clips under a gunwale.  If covered those covers should be easily removable.

A set of vernier calipers is best way to measure accurate size, (regularly on offer for as  £10), but if you just close an adjustable wench on to the pipe, and use a ruler to measure the resulting gap in the jaws, that should be more than sufficient to identify if you have 1/2" or 3/8" feed.  (It could be metric pipe, of course, but even so a measurement taken as suggested is a good starting point.  As Nick says you also need to measure the total length of feed from the regulator in the gas locker to the appliances, because the longer the run, the greater will be the pressure drop with everything turned on.

[chubby]

 

55 minutes ago, nicknorman said:

If you just measure the outside diameter of the pipe running from the gas locker to the T, folk on here will have a pretty good idea of whether it will be suitable or not. And there should be some info on the data plate of the oven as to its max gas usage or heat output. That combined with knowing the same about the proposed water heater, and the approximate overall pipe length is all that is needed.

Thanks again 

Pipe outside diameter - 10mm 

info for hob / oven

hob -  vanette 4000/2 . manual states maximum heat input 6.55 kw 

Oven - vanette GG7000 . manual states maximum heat input : Oven / grill 3.3 kw 

does this help ? is this the info suggested ?

Thanks again 

Eta : will check morco gas needs shortly . distance from gas bottle regulator to isolation valves beside current oven / hob set up = 26  - 30 ft approx 

Edited January 30, 2018 by chubby

[alan_fincher]

Length of the main pipe?

Unless it is quite a short run, my gut feel is that your measured 10mm external diameter doesn't really make it suitable for adding a Morco to, and ideally it would be replaced up to the point where the supply divides for the two appliances by 1/2" pipe.

But without the length amy maths is impossible.

[chubby]

cheers - ive edited my previous reply to inlude pipe length of 26 - 30 ft between gas regulator & isolation taps 

[Alan de Enfield]

So you will have something in the order of 15Kw over about 10 metres.

This table shows that 3/8ths will just do the job.

 

Edited January 30, 2018 by Alan de Enfield

[ditchcrawler]

4 minutes ago, Alan de Enfield said:

I like that Kw, inches and meters all on one chart

[bizzard]

The 10mm tube is almost certainly thin wall and will have a larger diameter bore than 3/8'' thick wall tubing.

[alan_fincher]

4 minutes ago, bizzard said:

The 10mm tube is almost certainly thin wall and will have a larger diameter bore than 3/8'' thick wall tubing.

But do we know  that the 10mm measurement is a highly accurate one taken with (for example) vernier calipers.  If it is an approximate one taken by other methods the pipe may well be 3/8"?

How old is the boat, please, Chubby?  If not particularly new, and no evidence it has ever been re-plumbed, I would have thought imperial pipe far more likely as an original fitment?

How did you measure the 10mm, please?

[chubby]

10 mm was measured with a tape measure at a point where i could get good access to the pipe. The boat is a Liverpool 2001 . Ive owned it 5 years and i expect the pipework is original . 

I visited my nearest boatyard a short while ago & all this may seem a bit academic as the chap at the yard told me that simply getting your hands on a Morco is an achievement  in itself as theyve gone bust after a cost cutting exercise went pear shaped . He advised capping off the extra tap .

I think id like a morco tho if feasable ( but not the room sealed version ) as it operates without using battery power  , unlike my ebersplutter .

[MtB]

As always, the first step is to decide which set or sets of regulations you wish/need to comply with.

I don't think the BSS for example defines any particular pressure drop as the maximum you can have. The RCD on the other hand is very prescriptive. 

Bear in mind an instantaneous water heater will approximately double the heat load on the single gas pipe. It may well still work adequately for BSS though.

[ditchcrawler]

2 minutes ago, Mike the Boilerman said:

As always, the first step is to decide which set or sets of regulations you wish/need to comply with.

I don't think the BSS for example defines any particular pressure drop as the maximum you can have. The RCD on the other hand is very prescriptive. 

Bear in mind an instantaneous water heater will approximately double the heat load on the single gas pipe. It may well still work adequately for BSS though.

I don't see how he can if he is not even allowed to fit a manometer and relies on a bubble tester for leak testing, All he can do is observe the flames.  

51 minutes ago, chubby said:

10 mm was measured with a tape measure at a point where i could get good access to the pipe. The boat is a Liverpool 2001 . Ive owned it 5 years and i expect the pipework is original . 

I visited my nearest boatyard a short while ago & all this may seem a bit academic as the chap at the yard told me that simply getting your hands on a Morco is an achievement  in itself as theyve gone bust after a cost cutting exercise went pear shaped . He advised capping off the extra tap .

I think id like a morco tho if feasable ( but not the room sealed version ) as it operates without using battery power  , unlike my ebersplutter .

Are you going to change all your plumbing then and do away with your calorifer?

[MtB]

Just now, ditchcrawler said:

I don't see how he can if he is not even allowed to fit a manometer and relies on a bubble tester for leak testing, All he can do is observe the flames.  

 

Quite.

I'm pretty sure one of my boats has a cooker and a Morco both on the end of a 25ft 3/8" pipe and that installation has passed BSS multiple times.

[system 4-50]

2 hours ago, Alan de Enfield said:

So you will have something in the order of 15Kw over about 10 metres.

This table shows that 3/8ths will just do the job.

 

I do like the confusing dimensions on the RHS.  Are they IDs, & ODs, or nominal pipe sizes?

[Alan de Enfield]

13 minutes ago, system 4-50 said:

I do like the confusing dimensions on the RHS.  Are they IDs, & ODs, or nominal pipe sizes?

The numbers without brackets are the 'nominal pipe size' whilst the numbers in brackets are the 'outside diameter', both in inches.

The information is not clear, but if the OD is 1/2" then one can only assume that the 'nominal pipe size' refers to the ID as being 3/8"

Edited January 30, 2018 by Alan de Enfield

[blackrose]

Apart from pipe sizing the other thing to think about is whether you would be siting your gas water heater in a certain location just because there happens to be a redundant gas feed there? 

Pipework is just pipework and it should be modified to suit the location of the appliances, not the other way around. If your redundant gas feed just happens to be in the right position then fine, but don't make the mistake of fitting a gas water heater in an unsuitable position just because there happens to be a pipe there. 

[alan_fincher]

1 hour ago, Mike the Boilerman said:

I don't think the BSS for example defines any particular pressure drop as the maximum you can have.

I think you are correct.  The current boat doesn't yet have a bubble tester, so the BSS inspector had to do manometer tests to check for gas tightness.

However he did not use the manometer to look for pressure drop with everything on - he simply satisfied himself that everything was burning cleanly when they were.

1 hour ago, Mike the Boilerman said:

Quite.

I'm pretty sure one of my boats has a cooker and a Morco both on the end of a 25ft 3/8" pipe and that installation has passed BSS multiple times.

We currently still have a 3/8" feed supporting both a Morco and a cooker, (and a fridge, actually).  I'm not sure of length, but it's probably not far short of your 25 feet.  When I tried to check the maths / graphs, I though it was fairly marginal, but clearly it is sufficient to pass visual checks on the flames.  I will probably replace in 1/2" as and when I redo the kitchen. to stop anybody being picky on a future examination.

My gut feel, (rather than scientifically argued view!), is that if it's no further than that, an examiner will probably pass a combination of standard cooker with a Morco, but if the feed ran most of the length of a 60 or 70 foot boat, they probably might not.

[Alan de Enfield]

2 hours ago, Mike the Boilerman said:

I don't think the BSS for example defines any particular pressure drop as the maximum you can have.

They just use 'visuals'

8.8.1
Are all LPG appliance burners in good condition and delivering a proper flame? 

Light all LPG appliance burners and operate them at their maximum setting at the same time.
Compare the flame pictures at each burner to the ‘burner flame trouble chart’ at Appendix L.
A satisfactory flame picture must be present at each LPG appliance burner when all burners in the
system are operating at their maximum setting at the same time.

NOTE – any appliances with ‘hidden’ burners must be ignited as part of this check but there is no
requirement to see the burner flame picture.

NOTE – in the event of a poor flame picture, take the actions described in Appendix A or A and B, and if the
regulator is operating outside of the lock‐up tolerance, or is more than 10 years old, or is marked in imperial
units, the BSS Warning Notice must include a note about the performance or age of the regulator as
appropriate.
Examiner action ‐ Before operating the burners on any flued appliances, carry out the checks at 8.10.1/2/3.
The flame picture assessment should not be carried out if a fault at 8.10.1/2/3 is recorded.

NOTE – in the event any appliance burner cannot be lit mark your checklist ‘not verified’ and note the reason
why. In such cases the burner must be considered as non‐compliant until such time as its good condition has
been verified.

 

[bizzard]

I wonder who's supplying Instantaneous gas hot water heaters, Rinnai perhaps, to all the thousands of fast food vans, ice cream vans, mobile kitchens ect. They all have to have them or some way of heating water, by law, to wash their hands. Camping stoves and kettles maybe.