Article on Pumps

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meow...@care2.com

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Jun 25, 2007, 5:52:45 PM6/25/07
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Latest wiki thing is about pumps:
http://wiki.diyfaq.org.uk/index.php?title=Pumps

Suggestions and contributions welcome.


NT

John Rumm

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Jun 25, 2007, 8:02:20 PM6/25/07
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Brown, size 9.


--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

clot

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Jun 25, 2007, 8:12:21 PM6/25/07
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John Rumm wrote:
> meow...@care2.com wrote:
>> Latest wiki thing is about pumps:
>> http://wiki.diyfaq.org.uk/index.php?title=Pumps
>>
>> Suggestions and contributions welcome.
>
> Brown, size 9.


My Plimsolls are usually size 8 or 9 but this does vary according to the
manufacturer's line.

nightjar

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Jun 26, 2007, 12:54:46 PM6/26/07
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<meow...@care2.com> wrote in message
news:1182808365.8...@w5g2000hsg.googlegroups.com...

> Latest wiki thing is about pumps:
> http://wiki.diyfaq.org.uk/index.php?title=Pumps
>
> Suggestions and contributions welcome.

Considering that acetyl, PTFE, some PVCs, nylon, polycarbonate, polyethylene
and a few other plastics appear in the WRAS approved materials list, I
wonder if it is true that brass is required for potable water pumps.

Colin Bignell


Andy Hall

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Jun 26, 2007, 2:08:20 PM6/26/07
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On 2007-06-26 01:02:20 +0100, John Rumm <see.my.s...@nowhere.null> said:

> meow...@care2.com wrote:
>> Latest wiki thing is about pumps:
>> http://wiki.diyfaq.org.uk/index.php?title=Pumps
>>
>> Suggestions and contributions welcome.
>
> Brown, size 9.

I need 13. Apparently there is a correlation.


:Jerry:

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Jun 26, 2007, 2:40:25 PM6/26/07
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<meow...@care2.com> wrote in message
news:1182808365.8...@w5g2000hsg.googlegroups.com...
> Latest wiki thing is about pumps:
> http://wiki.diyfaq.org.uk/index.php?title=Pumps
>
> Suggestions and contributions welcome.
>

Timely.... for some no doubt! :~((


John Rumm

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Jun 26, 2007, 3:30:36 PM6/26/07
to
Andy Hall wrote:
> On 2007-06-26 01:02:20 +0100, John Rumm <see.my.s...@nowhere.null>
> said:
>
>> meow...@care2.com wrote:
>>> Latest wiki thing is about pumps:
>>> http://wiki.diyfaq.org.uk/index.php?title=Pumps
>>>
>>> Suggestions and contributions welcome.
>>
>> Brown, size 9.

The reference was to the two Ronnies sketch - fork handles etc. still
never mind...

> I need 13. Apparently there is a correlation.

You may be right....

I was told that todger length = collar size - shoe size

John Rumm

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Jun 26, 2007, 3:33:06 PM6/26/07
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Eebygum!

Andy Hall

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Jun 26, 2007, 5:34:17 PM6/26/07
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On 2007-06-26 20:30:36 +0100, John Rumm <see.my.s...@nowhere.null> said:

> Andy Hall wrote:
>> On 2007-06-26 01:02:20 +0100, John Rumm <see.my.s...@nowhere.null> said:
>>
>>> meow...@care2.com wrote:
>>>> Latest wiki thing is about pumps:
>>>> http://wiki.diyfaq.org.uk/index.php?title=Pumps
>>>>
>>>> Suggestions and contributions welcome.
>>>
>>> Brown, size 9.
>
> The reference was to the two Ronnies sketch - fork handles etc. still
> never mind...
>
>> I need 13. Apparently there is a correlation.
>
> You may be right....
>
> I was told that todger length = collar size - shoe size

Can't be. That would make it about -5cm.


John Stumbles

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Jun 26, 2007, 6:00:08 PM6/26/07
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On Tue, 26 Jun 2007 17:54:46 +0100, "nightjar" <nightjar@ wrote:

> Considering that acetyl, PTFE, some PVCs, nylon, polycarbonate,
> polyethylene and a few other plastics appear in the WRAS approved
> materials list, I wonder if it is true that brass is required for
> potable water pumps.

Shower pumps use various plastics and they must be suitable for potable.

--
John Stumbles

I forgot to take my amnesia medecine again

John Rumm

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Jun 26, 2007, 7:02:30 PM6/26/07
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Andy Hall wrote:
> On 2007-06-26 20:30:36 +0100, John Rumm <see.my.s...@nowhere.null>
> said:
>
>> Andy Hall wrote:
>>> On 2007-06-26 01:02:20 +0100, John Rumm
>>> <see.my.s...@nowhere.null> said:
>>>
>>>> meow...@care2.com wrote:
>>>>> Latest wiki thing is about pumps:
>>>>> http://wiki.diyfaq.org.uk/index.php?title=Pumps
>>>>>
>>>>> Suggestions and contributions welcome.
>>>>
>>>> Brown, size 9.
>>
>> The reference was to the two Ronnies sketch - fork handles etc. still
>> never mind...
>>
>>> I need 13. Apparently there is a correlation.
>>
>> You may be right....
>>
>> I was told that todger length = collar size - shoe size
>
> Can't be. That would make it about -5cm.

15" collar? Pencil neck!

(18" collar, size 10, so I do ok on that calculation ;-)

(they say that is why women have so many minor prangs in the car... we
have been telling them that "this long" is 8" for years!)

Owain

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Jun 26, 2007, 6:45:56 PM6/26/07
to
John Rumm wrote:
>> I need 13. Apparently there is a correlation.
> You may be right....
> I was told that todger length = collar size - shoe size

Working in inches or centimetres?

Anyway, I've put nearly two inches on my collar size in the last
<mumble> years, but nothing else has changed.

Owain

Andy Hall

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Jun 27, 2007, 5:53:42 AM6/27/07
to
On 2007-06-27 00:02:30 +0100, John Rumm <see.my.s...@nowhere.null> said:

> Andy Hall wrote:
>> On 2007-06-26 20:30:36 +0100, John Rumm <see.my.s...@nowhere.null> said:
>>
>>> Andy Hall wrote:
>>>> On 2007-06-26 01:02:20 +0100, John Rumm <see.my.s...@nowhere.null> said:
>>>>
>>>>> meow...@care2.com wrote:
>>>>>> Latest wiki thing is about pumps:
>>>>>> http://wiki.diyfaq.org.uk/index.php?title=Pumps
>>>>>>
>>>>>> Suggestions and contributions welcome.
>>>>>
>>>>> Brown, size 9.
>>>
>>> The reference was to the two Ronnies sketch - fork handles etc. still
>>> never mind...
>>>
>>>> I need 13. Apparently there is a correlation.
>>>
>>> You may be right....
>>>
>>> I was told that todger length = collar size - shoe size
>>
>> Can't be. That would make it about -5cm.
>
> 15" collar? Pencil neck!
>
> (18" collar, size 10, so I do ok on that calculation ;-)
>
> (they say that is why women have so many minor prangs in the car... we
> have been telling them that "this long" is 8" for years!)

I was working in cm and European show sizes.


Andy Hall

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Jun 27, 2007, 5:54:06 AM6/27/07
to

Have you tried the patches?


meow...@care2.com

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Jun 27, 2007, 6:52:48 AM6/27/07
to
On 26 Jun, 17:54, "nightjar" <nightjar@<insert my surname
here>.uk.com> wrote:
> <meow2...@care2.com> wrote in message
news:1182808365.8...@w5g2000hsg.googlegroups.com...

now added, thanks.


NT

John Rumm

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Jun 27, 2007, 9:35:42 AM6/27/07
to

Maybe it has, but you just can't look down as well as you used to ! ;-)

Aidan

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Jun 27, 2007, 2:56:28 PM6/27/07
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On 25 Jun, 22:52, meow2...@care2.com wrote:
> Latest wiki thing is about pumps:http://wiki.diyfaq.org.uk/index.php?title=Pumps
>
> Suggestions and contributions welcome.

It seems to be mostly wrong.
I'd suggest you bin it.

:Jerry:

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Jun 27, 2007, 3:53:30 PM6/27/07
to

"Aidan" <one...@talk21.com> wrote in message
news:1182970588.3...@k79g2000hse.googlegroups.com...

Perhaps you might like to suggest new content to replaces 'it'?...


The Medway Handyman

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Jun 27, 2007, 6:50:43 PM6/27/07
to
John Rumm wrote:

>>> Brown, size 9.
>
> The reference was to the two Ronnies sketch - fork handles etc. still
> never mind...
>
>> I need 13. Apparently there is a correlation.
>
> You may be right....
>
> I was told that todger length = collar size - shoe size

My collars are tight and I have very small feet - good news :-)


--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257


clot

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Jun 27, 2007, 7:01:45 PM6/27/07
to
The Medway Handyman wrote:
> John Rumm wrote:
>
>>>> Brown, size 9.
>>
>> The reference was to the two Ronnies sketch - fork handles etc. still
>> never mind...
>>
>>> I need 13. Apparently there is a correlation.
>>
>> You may be right....
>>
>> I was told that todger length = collar size - shoe size
>
> My collars are tight and I have very small feet - good news :-)

Hmm. Wearing a tight shirt on a small neck? :)

meow...@care2.com

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Jun 28, 2007, 3:26:49 PM6/28/07
to

Somehow I doubt he will :)


NT

Aidan

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Jun 29, 2007, 2:32:59 PM6/29/07
to

Like the summarize Proust contest..........

>Real world flow rate is normally far below the manufacturers claimed flow rate. Flow claims are normally based on there being no pipe connected to the pump outlet.

No, they don't.
A pump will produce a specific flow rate at a specific differential
pressure (assuming constant speed). A flow rate is meaningless unless
the associated dP is quoted. Manufacturers usually supply pump curves
for each model. The only pump/fan manufacturers who are given to
claiming flow rates without the relevant dP are shower pump/ bathroom
fan manufacturers, selling to a (largely) clueless DIY market (3 bar
shower pumps? 1,000 lpm fans?). They will produce the curves, if
asked.

>In the real world:


>The pump operates against a column of water (or head) which provides back pressure
Not necessarily. You can pump water uphill, downhill & on the level.
Circulators (CH) have no static head 'cos the ascending flow is
balanced by the descending return (or v v) , so they only operate
against pressure loss due to pipe resistance at the specifed flow
rate.

>Pipes have resistance to water flow
Yes. The point is that the resistance is a loss of energy which
manifest itself as a loss of pressure due to resistance. See
Bernouilli.

>A better idea of real life flow can be gained by plotting head versus flow rate on x,y axes, and drawing a straight line from max flow to max head. This enables flow rates to be read off for any given head.

No. Really, no. It's a curve, which you get from the manufacturers.
You estimate the system resistance at the design flow.

>This does not take piping resistance into account, which will lower flow rates further

No. See above. You estimate system resistance etc..


Plumbing 2 pumps in series gives a total head of the 2 pumps added
together.
Yes, but only in theory.
In reality the system operating point is at the intersection of the
pump and system curves, so changing the flow in a given system alters
the system pressure loss and so the pumps' flow rate.
l
[edit]Pump Power
[edit]Pump Materials
Brass: used for potable water

Bronze usually, SS more recently ISTR.
The relevant question is, why?
'Cos potable/mains water is oxygenated and will corrode the steel
impeller on ordinary CH circulators. CH systems should be treated with
inhibitors, potable isn't. Dodgy plumbers use CH circulators on DHWS
circulating system, but they only last a year or two, at most .


Plastics: some are approved for potable water.
[edit]Connections
[edit]Pump Types
Add spiel about cavitation & NPSH here; essential to limit DHWS flow
temperature on shower pumps to 60 degC, as per manufacturers'
recommendations 'cos it increases likelihood of cavitation. Cavitation
will chew lumps out of the impeller, be it bronze or plastic.


[edit]Central Heating circulator
Very quiet operation
Long service life
Speed adjustable.
too fast can cause pumping over & noise
too slow can cause boiler kettling
Standardised pipe fittings.

1 1/4" BSP unions ISTR, but Yanks use 2-bolt flanges on similar/same
pumps.
They are canned rotor/glandless circulators, which are what really
made domestic CH possible in late 50s/early 60s.
Pumps formerly used stuffing boxes which had to just drip (or else
they were piped to the inlet/suction flange) or the gland packing
would burn out. Packed glands have largely been replaced by carbon/
ceramic seals on commercial pumps. There's a web-site somewhere with
several hundred pages just on carbon seals.

The pump is glandless because the motor rotor is in the water stream
(in the 'can') , so there's no shaft from motor to pump which needs to
be sealed on the pump scroll/casing. The relevant point is that
there's very little clearance between rotor and stator to get the
magnetic flux (electronics geeks please provide correct terminology)
to turn the rotor. This narrow waterway will get blocked easily if
there's any corrosion debris in the heating system.
The jammed rotor can usually be cleared by spinning it manually or
you can dismantle the pump and clean it. Dodgy plumbers charge for a
new pump ( "It's yer pump, darlin' etc.",) and flog the cleaned-up old
pump to their next victim.
If the pump blocks regularly, you have a corrosion problem, probably
the result of employing incompetent, dodgy plumbers. You could fit a
glanded pump with a separate motor which won't block, but these cost
lots (£200ish, ISTR). I only fitted that to a centralised heating
system because there was no propect of being able to clean up the
system water quality.


[edit]Shower
Boost shower pressure and thus flow
Boosts bills too.
[edit]Sump pump
For draining cellars prone to flooding.
USually automatically operated by a water sensor
[edit]Drill Pump
Small minimal cost pump for occasional clear-up use
[edit]Foul Water Pump
Able to handle debris in the water

Borehole, multi-stage, end-suction, belt drive, inverters, variable
speed pumps, etc..


The thing is this Wiki is under the control of NT who thinks he knows
something about pumps (and everything else) and can write a useful
article in 100 words. Truth is he knows sod-all about pumps and his
efforts are misleading.
I work with/specify pumps, it would take me several hours to
construct a useful article and I KNOW that I know sod all about
pumps because I occasionally come into contact with pump specialists.
I also work with/specify heat transfer equipment. The last time I had
a disagreement with NT about this (he thinks he knows about heat
transfer, too) he suggested I consider a uniform resistive block. I
have yet to find out what a uniform resistive block is; if anyone can
help, please advise me.

I'm not spending my time producing anything for the benefit of NT.
See Wikipedia.

John Rumm

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Jun 29, 2007, 3:52:29 PM6/29/07
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Aidan wrote:

> The thing is this Wiki is under the control of NT who thinks he knows

No its not! You can go and make changes to any article you like. You
don't even have to create an account first (although it helps if you do).

You can't fault NT for the shear quantity of stuff he has added to the
wiki, even if much of it represents a "good starting point" rather than
a polished result!

> something about pumps (and everything else) and can write a useful
> article in 100 words. Truth is he knows sod-all about pumps and his
> efforts are misleading.

On pumps I would have to agree. Not being an expert on the subject I
have refrained from fiddling even though a number of statements have
struck me as improbable.

> I work with/specify pumps, it would take me several hours to
> construct a useful article and I KNOW that I know sod all about
> pumps because I occasionally come into contact with pump specialists.

Well much of what you posted already could be used to good effect in the
article, so why not have a bash?

> I'm not spending my time producing anything for the benefit of NT.
> See Wikipedia.

How would adding / correcting useful material be for the benefit of NT?
Surely it would be for the benefit of the rest of us?

John Stumbles

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Jun 29, 2007, 5:33:00 PM6/29/07
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On Fri, 29 Jun 2007 20:52:29 +0100, John Rumm wrote:

> On pumps I would have to agree. Not being an expert on the subject I
> have refrained from fiddling even though a number of statements have
> struck me as improbable.

I think there's a point to be considered here. I also know a little about
pumps but have not contributed to this article because I'd rather
concentrate on trying to do a few articles as well as I possibly can than
adding a bit to an article which - it seems to me - requires a lot of work
to bring to a good standard. I'm not saying NT/meow shouldn't have written
what he did but I've been wondering about somehow separating articles that
are seriously 'under construction' from more complete and accurate ones.
I'm raising this in a separate thread called "DIY Wiki - articles Under
Construction"

--
John Stumbles

Bitwise, byte foolish

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