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Blanking of unused gas spur?


blackrose

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I've sold my 3 way fridge and will be replacing it with an A+ (F) mains fridge that I can run from solar panels via my inverter.

 

Is there some sort of blanking plug I could put into the bottom of the unequal T fitting or a way of blanking off the curved spur at the bottom,  or would that be seen as an unnecessary joint by the BSS inspector? Should I just replace that fitting on the left of the picture with an unequal straight coupling? I think it's 1/2" to 1/4"

 

IMG_20220912_202730.jpg

Edited by blackrose
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9 minutes ago, blackrose said:

Thanks, but the other part of my question was, is blanking it off going to be seen as an unnecessary joint?

Ideally a straight coupling would be best. Not sure if a blanking nut (if it’s the correct type) would be an issue. Depends what side of the bed the examiner got out I suspect 

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49 minutes ago, blackrose said:

Thanks, but the other part of my question was, is blanking it off going to be seen as an unnecessary joint?

The BSS checklist for private boats states “Identify any pipework spurs that are no longer connected to an appliance and check they are closed with a ‘tools-to-remove’ proprietary stop-end”.  So whilst the pipe system design is required to avoid unnecessary joints, it does recognise that changes may be made to the system resulting in dead spurs.  So I think you should be ok if the above is complied with.

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9 hours ago, Chewbacka said:

The BSS checklist for private boats states “Identify any pipework spurs that are no longer connected to an appliance and check they are closed with a ‘tools-to-remove’ proprietary stop-end”.  So whilst the pipe system design is required to avoid unnecessary joints, it does recognise that changes may be made to the system resulting in dead spurs.  So I think you should be ok if the above is complied with.

Yes,

I think this is the correct answer.

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Simply super-glue the tap firmly shut in the closed position!  😂

Seriously though, replacing the Tee with a Test Point sounds favourite to me.  It's certainly the arrangement an over-zealous BSS inspector is likely to take issue with.

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35 minutes ago, Loddon said:

Capping it there is not good practice.

If you want to cap it off do it at the T piece at the top in the first photo.

Or better replace the T with a test point as suggested earlier.

 

What's the difference? Wherever I cap it there will be unnecessary joints. One more joint if I leave the isolator in place granted.

 

15 minutes ago, alan_fincher said:

Simply super-glue the tap firmly shut in the closed position!  😂

Seriously though, replacing the Tee with a Test Point sounds favourite to me.  It's certainly the arrangement an over-zealous BSS inspector is likely to take issue with.

 

I'd rather not put a test point in. If I do an examiner may then question why there is no test point on the other gas line (I have 2 separate systems on my boat).

 

If Chewbaka's interpretation is correct then I see no problem in capping off the spur after the isolator.

Edited by blackrose
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22 minutes ago, Tracy D'arth said:

Its a union nut, could be anything.  Use the existing nut with a blank in place of the pipe.

 

I don't have the existing nut. It went with the fridge. 

Just now, Loddon said:

Capping the T is easier ;)

 

 

Only if I can find a cap of the correct size. 

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My thinking was that if one is allowed to cap an unused spur then if I remove the spur completely I just end up with an unnecessary joint in the main run. An examiner might look at it and think "Why is that joint there?" But if I leave the spur in place he can see why the joint is there and that it's been capped.

3 minutes ago, Loddon said:

There are caps made for the T, available at most plumbers merchants.

 

 

Ok that might be easier then.

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The nearest standard pipe thread in my screw thread book is 3/8" BSP, which is 19 TPI and as a taper thread, a diameter going from 0.5886"  to 0.6560" .

The closest American NPT thread (3/8") has 18 TPI and a diameter of around 0.612" to 0.627". 

 

But, as noted above, there is no pressing need  for standardisation of the threads for the nuts of compression fittings. In the 1970's when I was installing  my own central heating,  the two main brands of compression fittings for 15mm and larger pipes were Conex and Prestex.  One (Conex I think) used the standard BSP thread for its compression nuts, while the other used a significantly finer thread, and builders' merchants used to  stock spare nuts for both brands. Nowadays everyone seems to use the BSP threads.  

 

 

Edited by Ronaldo47
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Fine thread compression nuts were the spawn of Satan.  Easy to cross thread, easy  to over tighten and took longer to fit because there were more turns of thread.   The modern Rp (BSP P)  threaded ones are much better.

 

N

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2 hours ago, blackrose said:

My thinking was that if one is allowed to cap an unused spur then if I remove the spur completely I just end up with an unnecessary joint in the main run. An examiner might look at it and think "Why is that joint there?" But if I leave the spur in place he can see why the joint is there and that it's been capped

If you remove the unequal tee and replace it with a straight coupling, there would not be an unnecessary joint; the coupling is performing the function of a reducer.   I suppose if the adjacent valve could be replaced by one taking unequal pipes, it would be possible to have one less fitting, but that is a fine point.

 

The male thread you want to cap could be anything; there is no particular reason to believe it is BSP.  You could try a few caps but even if the pitch and diameter feel about right, the thread forms might differ.  Maybe worth taking a chance with water, but less so with gas on a boat.

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