Plumbing Question (1) - Basin Wates

[alan_fincher]

I've just bought a basin and a tap and basin waste.

Looking at sites like Screwfix or Toolstation it appears most basin wastes are 1 1/4" or 32mm.

However mine measures up as more like 1.625" or 41.3mm, which has confused me somewhat, as I can't find much reference to what this size may be.

Somehow I need to reduce it to something like 3/4" for a push on flexible hose, preferably with some kind of barbed connector like this, (the barbed bit obviously, the nut on his is a fraction of the size it would need to be.

Any ideas how I might achieve this, or who may supply the bits, please?

 

Edited March 3, 2018 by alan_fincher

[rusty69]

 Recently had the same problem. I took the waste outlet into a local plumbers merchant,and after lots of scratching of heads and a number of opened packages,the bloke declared he could do it. Ended up using some glue, but it works.

Did I mention.It aint a pretty solution?

Edited March 3, 2018 by rusty69

[Alan de Enfield]

6 minutes ago, rusty69 said:

 Recently had the same problem. I took the waste outlet into a local plumbers merchant,and after lots of scratching of heads and a number of opened packages,the bloke declared he could do it. Ended up using some glue, but it works.

Did I mention.It aint a pretty solution?

So, by the time that lot was assembled the outlet was 6" below the water line.

[rusty69]

1 minute ago, Alan de Enfield said:

So, by the time that lot was assembled the outlet was 6" below the water line.

It was sposed to be a quick fix until I came up with a more elegant solution.So wait in anticipation  of a better solution.

[AndrewIC]

1 hour ago, alan_fincher said:

I've just bought a basin and a tap and basin waste.

Looking at sites like Screwfix or Toolstation it appears most basin wastes are 1 1/4" or 32mm.

However mine measures up as more like 1.625" or 41.3mm, which has confused me somewhat, as I can't find much reference to what this size may be.

Somehow I need to reduce it to something like 3/4" for a push on flexible hose, preferably with some kind of barbed connector like this, (the barbed bit obviously, the nut on his is a fraction of the size it would need to be.

 

Yours looks like 1 1/4" BSP. Have a look at the BSP thread sizes (Wiki), and you will see that the BSP sizes are, for most boaty sizes, roughly about a 1/4" smaller than the actual measured size (so a 3/4 BSP fitting measures about an inch across the threads)

It's usually a case of trawling round plumbing and chandlery sites to assemble a combination of bits that will fit together and nit be too deep. I think I ended up with a low profile trap set from B&Q, an odd sized elbow from an aquarium place, and a length of 1" hose!

[alan_fincher]

1 hour ago, alan_fincher said:

I've just bought a basin and a tap and basin waste.

Looking at sites like Screwfix or Toolstation it appears most basin wastes are 1 1/4" or 32mm.

However mine measures up as more like 1.625" or 41.3mm, which has confused me somewhat, as I can't find much reference to what this size may be.

Somehow I need to reduce it to something like 3/4" for a push on flexible hose, preferably with some kind of barbed connector like this, (the barbed bit obviously, the nut on his is a fraction of the size it would need to be.

Any ideas how I might achieve this, or who may supply the bits, please?

 

Bugger!

Already can't correct original post.

On looking again, I now reckon what I have is actually a normal 1 1/4" BSP fitting.  Wikipedia gives the major diameter for 1 1/4" BSP as 1.65" or 41.9 mm which is pretty close to what I actually measured, (and I think my Lidl supplied gauge is a bit suspect!)

So where does the 32mm come from that the likes of Screwfix and Toolstation ae giving for all their basin waste fittings?  Clearly it's not the actual diameter of the threads, so is that what the pipe size ends up being, even though nothing on the waste itself actually measures 32mm ?

Anyway, if I'm right and this is just a "normal" 1 1/4" BSP waste, all I need to do is adapt it down to a barbed hose fitting for about 3/4" ID hose.

Sounds simple, but is it?

Any suggestion for sources of bits?

[nb Innisfree]

1 hour ago, alan_fincher said:

I've just bought a basin and a tap and basin waste.

Looking at sites like Screwfix or Toolstation it appears most basin wastes are 1 1/4" or 32mm.

However mine measures up as more like 1.625" or 41.3mm, which has confused me somewhat, as I can't find much reference to what this size may be.

Somehow I need to reduce it to something like 3/4" for a push on flexible hose, preferably with some kind of barbed connector like this, (the barbed bit obviously, the nut on his is a fraction of the size it would need to be.

Any ideas how I might achieve this, or who may supply the bits, please?

 

1 1/2" bsp. Assuming it's for a boat much better to dispense with a trap and use a connector from a 1 1/2" skin fitting straight onto the basin waste, 1 1/2" hose from that to a 1 1/2" skin fitting in the hull side. No more blockages. 

[alan_fincher]

2 minutes ago, AndrewIC said:

Yours looks like 1 1/4" BSP. Have a look at the BSP thread sizes (Wiki), and you will see that the BSP sizes are, for most boaty sizes, roughly about a 1/4" smaller than the actual measured size (so a 3/4 BSP fitting measures about an inch across the threads)

It's usually a case of trawling round plumbing and chandlery sites to assemble a combination of bits that will fit together and nit be too deep. I think I ended up with a low profile trap set from B&Q, an odd sized elbow from an aquarium place, and a length of 1" hose!

Snap!  I have justrealised where I was going wrong.  Why do trade outlets appear to quote basin wastes as 32mm, I wonder?  That's what threw me ff track.

This is the kind of case where somewhere like Screwfix may have suitable bits, but because they don't have detailed descriptions you can't tell without actually handling the bits.

I need something like this, but am sure the nut on that is unlikely to fit my trap.....

https://www.screwfix.com/p/floplast-hose-connector/48625?tc=AL2&ds_kid=92700020953274405&ds_rl=1249799&ds_rl=1245250&ds_rl=1249481&gclid=EAIaIQobChMI67-_p5LQ2QIVyLftCh2Y-AdSEAQYASABEgK0kvD_BwE&gclsrc=aw.ds&dclid=CMGllcql0NkCFTIh0wodBxcFMg
 

[nb Innisfree]

1 minute ago, nb Innisfree said:

1 1/2" bsp. Assuming it's for a boat much better to dispense with a trap and use a connector from a 1 1/2" skin fitting straight onto the basin waste, 1 1/2" hose from that to a 1 1/2" skin fitting in the hull side. No more blockages. 

Just read latest posts. If 1 1/4" bsp then use that size instead. 

[nbfiresprite]

This Ebay seller should have the connector you need.

https://www.ebay.co.uk/itm/PVC-Hosetail-x-Female-Threaded-Elbow-FBSP-12mm-20mm-25mm-32mm-40mm-50mm/201263582347?ssPageName=STRK%3AMEBIDX%3AIT&var=500460953572&_trksid=p2055119.m1438.l2649

[BEngo]

32 mm is the metric equivalent of 1 1/4 inches.  1 1/4 inches is the inside diameter of the pipe on which a 1 1/4 BSP thread can be cut.  32 mm plastic pipe is 32mm ID.

 

You either want a female  hose tail for 1 1/4 BSP or to find a washing machine or dishwasher outlet  pipe connector.  These are for putting dishwasher drains into sink waste plumbing.  You may find it easier to find one for 1 1/2 in pipe (BSP thread)  (38 mm) in which case a 1/1/4 female to 1/1/2 in male adaptor will be available from your local plumbers merchant.  Try to get a brass one as the steel ones go rusty and split the plastic fittings!

BES are always a god bet for plumbing fittings but also Plumbcenter.

 

For a hosetail try https://www.thehosemaster.co.uk/swivel-nut-washer-and-flat-tail     Lots of hosetails there. You might want  to reduce the sink outlet to a smaller diameter using standard BSP components, depending on what size hose you need.

N

[AndrewIC]

2 minutes ago, alan_fincher said:

Why do trade outlets appear to quote basin wastes as 32mm, I wonder?  That's what threw me ff track.
 

Because they refer to the OD of the waste pipe, 32mm and 40mm being the usual sizes.

[nb Innisfree]

2 minutes ago, alan_fincher said:

Snap!  I have justrealised where I was going wrong.  Why do trade outlets appear to quote basin wastes as 32mm, I wonder?  That's what threw me ff track.

This is the kind of case where somewhere like Screwfix may have suitable bits, but because they don't have detailed descriptions you can't tell without actually handling the bits.

I need something like this, but am sure the nut on that is unlikely to fit my trap.....

https://www.screwfix.com/p/floplast-hose-connector/48625?tc=AL2&ds_kid=92700020953274405&ds_rl=1249799&ds_rl=1245250&ds_rl=1249481&gclid=EAIaIQobChMI67-_p5LQ2QIVyLftCh2Y-AdSEAQYASABEgK0kvD_BwE&gclsrc=aw.ds&dclid=CMGllcql0NkCFTIh0wodBxcFMg
 

Any reduction in diameter combined with a trap is bound to cause blockages. As it drains straight into the cut there's no need for a trap. 

[bizzard]

Indeed a smooth streamlined outward flow. Any internal ridges in the fittings facing the sink direction will continually trap muck and block up.

[dmr]

Metric bolts specify the diameter of the bolt itself, an m8 bolt really is 8mm diameter (over the threads), but BSP is plumbing stuff (British Standard Pipe) and in this case the size is the diameter of the hole where the water flows. The logic here is that the main factor when designing a pipe installation is the size of the hole for the water to flow down!!!!

Other systems are even stranger, in the old imperial AF bolts (Across Flats) its the size of the bolt head not the threaded part of the bolts.

The BA (British Association) system, once much used for electrical items, starts at 0BA which is an m6 bolt (almost) but with a different "AF" size of head. Smaller bolts have bigger numbers relating to the number of 90% reductions (I think), so 2BA = 0Ba x 0.9 x 0.9.

...............Dave

 

[system 4-50]

This problem has been addressed before on this forum but I can't get the awful search system to find it despite knowing I responded to it.

I found it necessary to get an hose to waste angle and to scrape the little lip inside the fitting off and assemble it with bodge stuff (LSX) and that worked well. 

 

 

[David Mack]

Domestic waste fittings are 1 1/2 BSP for sinks and 1 1/4 BSP for washbasins and fittings connect to 38mm and 32mm pipe. As you have found out the domestic plumbing suppliers don't have anything to fit 3/4 hose. 

One option is to use larger diameter all the way to the skin fitting. Belfast has been plumbed this way, and there is less chance of getting food waste or other debris blocking the pipe.

Alternatively you need a waste fitting made for the job. Something like Midland Chandlers part no 75332.

 

[alan_fincher]

3 minutes ago, David Mack said:

Domestic waste fittings are 1 1/2 BSP for sinks and 1 1/4 BSP for washbasins and fittings connect to 38mm and 32mm pipe. As you have found out the domestic plumbing suppliers don't have anything to fit 3/4 hose. 

One option is to use larger diameter all the way to the skin fitting. Belfast has been plumbed this way, and there is less chance of getting food waste or other debris blocking the pipe.

Alternatively you need a waste fitting made for the job. Something like Midland Chandlers part no 75332.

 

Yep, that is probably the route I'm going with the bath, but the bath is "plastic, and only about half a centimetre thick.

The basin is a very heavy ceramic one, several centimetres thick at the plughole.  I could probably use something like this, but it would need a much longer bolt, as a minimum modification.

https://www.midlandchandlers.co.uk/search.aspx?q=75332

However the waste I have ended up with is quite a good quality pop up one, avoiding a plug and chain, so I'll experiment with adapting that first if I can bodge something up, I mean hand craft a perfect solution!

9 minutes ago, system 4-50 said:

This problem has been addressed before on this forum but I can't get the awful search system to find it despite knowing I responded to it.

Yes, I had a quick look, but latest incarnation of search not working for me either.

[system 4-50]

4 minutes ago, alan_fincher said:

Yes, I had a quick look, but latest incarnation of search not working for me either.

Sorry, that sounded like a criticism of you but it wasn't meant to be.  I want to find it as I think I included in it the source of the angle which I have now forgotten.

[koukouvagia]

I had precisely this problem when fitting a wash hand basin on top of one of the elm bottoms I'd turned into a stand.

I made up my own fitting , using some epoxy metal filler.  It was only meant as a temporary solution until I found a more elegant solution.  However, it works perfectly and nothing seems to get trapped, so I've left it alone.

[Batavia]

My solution on the latter stages of Daedalus and on Batavia was to fit a brass 1 1/4" elbow on the end of the metal waste fitting (avoid plastic at all costs) and then fit a brass hose barb into the end of the elbow using a reducer, then hose to the skin fitting.  the whole assembly is very robust and no bodging is required.

Although there is a "step" in the flow path, in practice this didn't seem to be a major problem with a 3/4" hose - depending obviously on what you put down the waste (and 1" would be even less problematic).  On the odd occasion it did partially block, a swift poke with a length of wire up through the skin fitting cleared the blockage.

 

Chris G

[dor]

My solution:

Marine grade hose double clipped with SS jubilees means the top of the sink becomes the top and is above 10 inches above water line.  PVC cemented or pushfit joints best avoided acording to the surveyor that checked my build.

 

[Neil Smith]

I did my bath, sink and basin the same way, went to my local plumbers and bough a 90% bend with correct thread then screwed on a washing machine hose tail that takes 3/4" hose then a stainless steel jubilee clip to secure all work well and keep the skin fittings well above water level.

Neil

[Iain_S]

3 hours ago, dmr said:

(snip)

Other systems are even stranger, in the old imperial AF bolts (Across Flats) its the size of the bolt head not the threaded part of the bolts.

The BA (British Association) system, once much used for electrical items, starts at 0BA which is an m6 bolt (almost) but with a different "AF" size of head. Smaller bolts have bigger numbers relating to the number of 90% reductions (I think), so 2BA = 0Ba x 0.9 x 0.9.

...............Dave

 

 An imperial bolt is defined by diameter : the spanner is AF (apart from Whitworth) A 1/2" bolt head is 3/4" AF. 

The BA syatem is quite interesting, as it's a metric thread developed about 80 years before the UK went metric. The starting point is 6mm diameter and 1mm pitch, the same as an M6 thread, apart from the thread angle, and therefore thread depth. 

[Bod]

Are hydraulic fittings BSP?

https://hydraulicmegastore.com/product/bsp-90-swept-hose-insert/

0151-20-20

1-1/4″ BSP 90° Swept Female – 1-1/4″ Hose Insert

Might work.

 

Bod