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Whale Watermaster


The Lea's
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Assuming you don't mean 8ft above, then yes.  Also I would use 22mm pipe for a long run like that.

I like having an accumulator as the water flows nice and steady with the tap open, without it the flow tends to fluctuate.

 

Added - I had a Jabsco and when it died I replaced with a Whale watermaster, I think it a better pump.

Edited by Chewbacka
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18 hours ago, The Lea's said:

Hiya all. Just purchased a Whale Watermaster FW1214(b). Would it be okay to site it 8ft away from water tank? Also, would you recommend an accumulator tank as it states on instructions optional? Cheers.

 

17 hours ago, Chewbacka said:

Also I would use 22mm pipe for a long run like that.

 

 

Solid advice above regarding the long run. Also consider using clear food grade suction hose with a wire spiral (cheaply available from eBay) - you can see what's going on if you have issues and it won't collapse under suction. You'd be ok with 15mm then and this will avoid any need  to change fittings on your pump (or your mesh screen filter before it - don't forget that bit).

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On ‎04‎/‎08‎/‎2019 at 16:12, Chewbacka said:

.  Also I would use 22mm pipe for a long run like that.

.

 

.

If the pump is situated below the tank outlet, then 22mm will not bea problem. If however you are looking for the pump to lift, then 15mm preferable. The weight of water on a lift can reduce the pump's performance. Think of sucking through a drinking straw as opposed to a kitchen roll insert.

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47 minutes ago, Ex Brummie said:

If the pump is situated below the tank outlet, then 22mm will not bea problem. If however you are looking for the pump to lift, then 15mm preferable. The weight of water on a lift can reduce the pump's performance. Think of sucking through a drinking straw as opposed to a kitchen roll insert.

I don’t think that is right as the pump inlet port is a fixed diameter and suction will draw the water up.  For a given volume of water, the speed of water in the pipe will be slower in 22mm than 15mm, but the faster the water the greater the frictional losses, so 22mm is still better.  -  I think this is right, but happy to be corrected.

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1 hour ago, Chewbacka said:

I don’t think that is right as the pump inlet port is a fixed diameter and suction will draw the water up.  For a given volume of water, the speed of water in the pipe will be slower in 22mm than 15mm, but the faster the water the greater the frictional losses, so 22mm is still better.  -  I think this is right, but happy to be corrected.

I agree with you. It’s important to keep the flow speed down on the suction side, and the larger the pipe bore the slower the flow, which reduces frictional losses. Most references suggest at least one pipe size up from the pump’s inlet bore size. 

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If you refer back to my post, you will see that I have specified 2 situations; one if the pump is level with the tank bottom, and another if you are looking to get a lift. If lifting, the bore of the inlet pipe is important, as a bigger pipe has a greater weight of water to lift and may struggle. As I said, think of drinking straws.

This is a problem commonly encountered with oil supply to boilers,( with which I work), but the physics are the same with any liquid.

Edited by Ex Brummie
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On 04/08/2019 at 16:12, Chewbacka said:

Added - I had a Jabsco and when it died I replaced with a Whale watermaster, I think it a better pump.

Why do you think it's better? (I'm soon in the market for a pump.)

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26 minutes ago, starman said:

Why do you think it's better? (I'm soon in the market for a pump.)

It seems to have slightly more flow and cuts out at a slightly higher pressure and the difference between turn-on and turn-off seems tighter, so I get a stronger flow with less fluctuations.  No data, just my feeling

 

Edited by Chewbacka
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21 hours ago, Ex Brummie said:

If you refer back to my post, you will see that I have specified 2 situations; one if the pump is level with the tank bottom, and another if you are looking to get a lift. If lifting, the bore of the inlet pipe is important, as a bigger pipe has a greater weight of water to lift and may struggle. As I said, think of drinking straws.

This is a problem commonly encountered with oil supply to boilers,( with which I work), but the physics are the same with any liquid.

The pressure on a dam is dependent upon the depth of water and not on how long or wide the reservoir is.  Pressure is dependant upon height of water and not area.

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12 hours ago, Chewbacka said:

The pressure on a dam is dependent upon the depth of water and not on how long or wide the reservoir is.  Pressure is dependant upon height of water and not area.

Agreed, but we are not measuring pressure, we are considering the performance of a pump when expecting it to lift water.

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44 minutes ago, Ex Brummie said:

Agreed, but we are not measuring pressure, we are considering the performance of a pump when expecting it to lift water.

A pump lifts fluid by applying negative pressure to the top of the column of fluid. Suck the air out with a pump and the external air pressure pushes the fluid up the pipe.  Diameter makes no difference, but the speed of the fluid rising in he pipe will depend on diameter as a bigger pipe has a bigger volume of air to remove before the liquid arrives.  So if there is a small leak of air back through the pump then it may never be able to prime the pump, in which case a smaller pipe would help.

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5 hours ago, Chewbacka said:

A pump lifts fluid by applying negative pressure to the top of the column of fluid. Suck the air out with a pump and the external air pressure pushes the fluid up the pipe.  Diameter makes no difference, but the speed of the fluid rising in he pipe will depend on diameter as a bigger pipe has a bigger volume of air to remove before the liquid arrives.  So if there is a small leak of air back through the pump then it may never be able to prime the pump, in which case a smaller pipe would help.

External air pressure has no effect on lift. The liquid will find its level in an open circuit. If you then apply a suction pump to that circuit, that pump needs to be able to overcome the weight of the liquid. Study a few pump curves, and you will see that pipe diameter radically affects the performance of the pump. Go back to my original analogy of sucking through a drinking straw as opposed to a kitchen roll insert.

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The reason that no one has ever made a pump that can suck water from an open container up higher than about 30 feet is because that is atmospheric pressure.

It is just not possible.  If you want water up higher than that (say from a well) then you put the pump down the hole and push the water up.

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31 minutes ago, Chewbacka said:

The reason that no one has ever made a pump that can suck water from an open container up higher than about 30 feet is because that is atmospheric pressure.

It is just not possible.  If you want water up higher than that (say from a well) then you put the pump down the hole and push the water up.

I don't know why people do not recognise or refuse to accept this principle. I guess its probably because we insist on referring to suction when we rally mean blowtion. That is atmospheric pressure trying to blow water (in this case) into an area of lower pressure.

 

I would have thought that the effect Ex Brummie is seeing on the pump curves is more to do with trying to shift higher volumes of liquid through smaller bores and thereby creating friction. In other words the restricting effect of the bore but above a certain diameter for any given pump that will no longer apply.

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In the non boating world, there are many instances of negative head pumps, such as shower pumps and boosters. In the narrowboating world, most pumps will have a positive head, but there are advantages to a negative head, one being that in the event of frost damage, the tank will not empty itself into the bilge. Most of the common pumps for domestic water will self prime from a negative head, and will perform better with a 15mm feed than a 22mm feed. 

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7 minutes ago, Ex Brummie said:

In the non boating world, there are many instances of negative head pumps, such as shower pumps and boosters. In the narrowboating world, most pumps will have a positive head, but there are advantages to a negative head, one being that in the event of frost damage, the tank will not empty itself into the bilge. Most of the common pumps for domestic water will self prime from a negative head, and will perform better with a 15mm feed than a 22mm feed. 

That’s probably because the bigger the pipe the more air it needs to suck out of the pipe before the water arrives and centrifugal pumps don’t pump air very well, so there is (guessing) some air leakage back through the pump.  So long as the pump will prime, I still maintain that once it is pumping water a bigger inlet pipe will give more flow than a small pipe, but obviously not in excess of the pump capacity.

 

Just had a look at the spec sheet for this pump, and it can be up to 3m above the supply water level.

 

Anyway, I doubt we will ever agree, so let’s just agree to differ.

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2 hours ago, Chewbacka said:

That’s probably because the bigger the pipe the more air it needs to suck out of the pipe before the water arrives and centrifugal pumps don’t pump air very well, so there is (guessing) some air leakage back through the pump.  So long as the pump will prime, I still maintain that once it is pumping water a bigger inlet pipe will give more flow than a small pipe, but obviously not in excess of the pump capacity.

 

That is why you prime them 

Added link

https://books.google.co.uk/books?id=tppLmQ6qUEEC&pg=PA184&lpg=PA184&dq=fire+service+pump+maximum+lift+handbook&source=bl&ots=7d_YdjyLtH&sig=ACfU3U2eD5WPn8vzMapmnHLl4m-HkaROlg&hl=en&sa=X&ved=2ahUKEwin5tHu-fPjAhVBnVwKHVnQAZ8Q6AEwEHoECAkQAQ#v=onepage&q=fire service pump maximum lift handbook&f=false

Edited by ditchcrawler
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5 minutes ago, Ex Brummie said:

Agree to differ, O.K., but the 3mt you refer to is the discharge head, i.e the height to which it will pump.

No it is not.  It is the height at which it will self prime.

https://whalepumps.com/marine/siteFiles/resources/docs/resource-library/datasheets/Whale_Watermaster_pressure_pumps.pdf

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Quote

 

The full 14 page data sheet makes no mention of priming height, just discharge. It also specifies inlet as 1/2", and shows a reduction in output as would be expected in increased head/resistance. https://www.whalepumps.com/rv/siteFiles/resources/docs/resource-library/180.156_v4_0616_ah_db.pdf

As a professional in such matters, I'm now getting bored. We had agreed to differ.

 

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9 minutes ago, Ex Brummie said:

That’s an entirely different pump. That’s the 2” diameter pump that caravanners drop into their external wheeled water butt. 

11 minutes ago, Ex Brummie said:

makes no mention of priming height

It won’t do as that pump is operated submerged. 

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17 minutes ago, Ex Brummie said:

The full 14 page data sheet makes no mention of priming height, just discharge. It also specifies inlet as 1/2", and shows a reduction in output as would be expected in increased head/resistance. https://www.whalepumps.com/rv/siteFiles/resources/docs/resource-library/180.156_v4_0616_ah_db.pdf

As a professional in such matters, I'm now getting bored. We had agreed to differ.

 

The link I attached earlier for the pump we are actually talking about states self prime height of 3m.  It is very clear and on page 1 so no need to read 14pages.

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