What's the function of pumps?

Its just like pumping the water ?

Could anyone please explain me about the function of marine pumps?

Many thanks

 

There are a number of pumps on most modern boats larger than a skiff.

1. Bilge Pumps/ Removes normally accumualeted water in the bilges AND water in emergency situations. Manual, electric, or mechanically driven.

2. Engine Pumps/ Oil & Coolant circulating pumps. Fuel pumps.

3.Pumps associated with interior heating systems/ Lift pumps for fuel & water cirulating pumps for certain systems.

4. Fire-fighting Pumps

5. Freshwater Pumps/ Supply drinking water from tank(s).

6. Hydraulic Pumps/ Steering systems, anchor winches, ect...

And several (at least) that escape my mind or that I have not run across yet.

The above is a very involved area.

Get to know boats better in general & the various uses of pumps will become much clearer.

TGoz

 

thx for the good info.

But im still confusing with it : (

Each pumps systems got a different application?

and what's self-prime mean?

 

Try to Google "bilge pumps" for example. I just did and there is basic info to be had.

If you surf and/or read you can find basic info on all the pumps.
Takes some effort. But if you are serious about boats and boat design you should already be doing so.

I've looked over your past posts and the questions you put forth tell me that you lack alot of very basic knowledge pertaining to boats. You almost need that basic knowledge to be able to ask sensible questions on the Forum, and to make use of the info people take their time to answer you with.

Try International Marine Publishing (do Google search for them) for a decent variety of good reading material.

TGoz

 

A pump is a pump. "a rose by any other name..." A pump ois just a mechanical device to move fluid from one place to another almost always uphill, or out of some kind of tank. Anyway there are different types of pumps, There are pumps that use a piston to create a low pressure and suck the fluid up and out. There are pumps that use impellers that are usually very near or in the fluid and push the fluid rather than suck the fluid. But they all do the same thing, move fluids. The difference is the fluid, water, fuel, hydraulic fluids, oil, etc.

Self prime means you turn it on and it creates enough of a suction, low pressure or vacuum, to get the fluid moving without having to fill the system before hand. In times past most pumps had to be primed. In fact there are still pumps that have to be primed. When I was a kid we had a well and the hand pump for the well had to be primed before it would work. This means you have to fill the system beforehand with the fluid you are going to pump. Otherwise, the impeller goes round and round and nothing moves.

Oh yeah, I forgot eductors. They are another kind of pump that uses a venturi effect to increase the amount of fluid pumped. These are commonly used in fire pumps.

As was said you can learn a lot about pumps on the web. Just use google.

 

Ike,

How are you? Utmost respect for your posts. I still owe you a beer for taking me through the diesel tank diagnosis. Another story for another day.

I have to point out, though, that there is not one pump in the world that sucks.

Even the notoriously bad Sherwoods...still don't suck.

Really a misnomer that should be avoided at such a technologically advanced forum like this one. You know what I mean, I'm sure. Pumps can produce a pressure lower than atmospheric pressure, and then atmospheric pressure pushes fluid into the pump. Thats a self-primer. I know that you know this stuff, but we might as well stick to the basic physics and everyone will be on the same page. We can thank Blaise Pascal in the 17th Century for demonstrating that what we commonly think of as "vacuum" is really just below atmospheric pressures, and it wasn't easy for him to demonstrate this to the world.

Might sound nit picky, but it was a "shot heard round the world" in its day, and certainly helps people understand how pumps work. Clearly still poorly understood by many. With such a vague, strange question to start a thread, it really begs to get back to the basic science, not the specifics.

The real answer to the initial question is...

No different from any pump not on a boat!

Mike

 

Doing fine Mike.

Yeah I know, mia culpa. I know they don't suck, although I've had a few that really sucked! But, over the years I've found that not all of us have had high school physics, so when explaining the function of fuel pumps on gas powered boats I fell into the bad habit of using the terms suck and push to explaining why we put the pump on or near the engine. It isn't technically correct but it makes it easier for most to understand, especially those non-engineer types at the EPA.

But, thanks for keeping me on my toes.

Is it stil hot in Boston or have the leaves started to change? Soon all the leaf peepers will be headed north.

 

Pascal

Two nights this week with a low in the high 30's!

Still did some bodysurfing yesterday in the nice swells rolling in. No need for the wetsuit yet.

I see your point about the difficulty in explaining these pump issues. I admit I'm a slow learner and grappled with it quite a bit. When I finally got it, it was a bit of a eureka moment, though, and I find siphons and any kind of pump is easy to understand. So many pumps on boats! All different kinds, every system. Many real bright folks at this site, though, that probably will get it much quicker than I did, if it didn't already come naturally. Lets give 'em a try?

I take it your in DC then? For some reason I thought you were from Wash state. It makes the possibility of a beer one day all the more likely.

Mike

 

No Mike, I'm still out in Washington State. Been to two boat shows in a week. Started raining today for the first time in 3 months.

I was in DC for 20 years. Not anymore.

If you want a difficult one, try to explain how an eductor works to someone who knows nothing about the laws of pressure/volume.

 

Here's how pumps work-


First the lady sits down. Then she slips them over her feet, or steps into/onto them and straps them to her feet (depending on the design). Then she stands up and she is a few inches taller. The other benefit is that it stretches the calf muscles and gives her legs a nicer, more toned, appearance.

Of course, this description is useless without pictures, but I'll leave that up to others.


Hope that helps!

 

Pumps!



Ahh! You see, its not so easy. You got it wrong, Toot. Pumps don't stretch the calf.

The pump puts her in a natural "plantar flexion" which puts the calf muscle (gastroc and soleus muscles) in a contracted appearing state. The reverse pump, or in a "dorsiflexion" position- trying to bend the toes toward the shin- is what would stretch the muscle.

Maybe we should consult the female members on pump function!


And I really need to stop checking in here so often.....!

 

Yeah I know, mea culpa. I know they don't directly stretch the calf, although I've seen a few women that really looked sexy in them! But, over the years I've found that not all of us got the chance to study a girl's anatomy in high school, so when explaining the function of pumps I fell into the bad habit of using the terms stretching and "calf muscles" to explain why ladies put the pump on their feet rather than their hands. It isn't technically correct but it makes it easier for most to understand, especially those non-engineer types at the strips clubs.

But, thanks for keeping me on my toes.






(In all seriousness, no offense is intended toward Ike. I'm just having a little fun here. Though, ironically, my previous longterm girlfriend WAS an environmental engineer- graduated from Northwestern..... and she in fact worked at, of all places, the EPA)

 

Pretty funny, Toot. A good laugh at least as much at my expense as others, so...my compliments. But you really should take more time to study female anatomy.


Unfortunately for all of us, I had to go to the DMV today to register a car, and killed the hours watching the counter tick up to my number by trying to recall the paper by Pascal that moved me so much when I read it. It did the trick and I survived the experience without choking anyone. I loved that paper and thought I might torture everyone with its historical significance.

"A Not Necessarily Serious Tribute to Blaise Pascal"

By bilgeboy

We all know how a siphon works. From the time when you were a little boy, and you first saw someone doing work for free, you were fascinated by this little invention, and figured out how to reproduce your own siphon. You use one from time to time, and they are really great, because you can spend time drinking a beer while this clever device does the work that you would have otherwise been doing (draining your bilge while on the hard in the Spring, draining a pool, emptying a barrel, etc, etc). Instead of holding a bucket, you are now holding a cold 12 ouncer.

Well, with the recent spike in fuel prices in the US, I'm sure a few of you have been re-contemplating the utility of this great invention. Suppose we were to consider borrowing some gasoline from a friendly neighbor, since we ran out of fuel just a few blocks from the mall.

Its easy to get it started. Just consider the height from the top of the gas in your friends car to the opening of the fuel fill ( Distance A ) and the height from the fuel fill to your empty container ( Distance B ). We all know that we can make a siphon if we have a length of hose that makes Distance B longer (lower) than Distance A, so that the vertical height of A is less than B. As long as this relationship holds true, you can make yourself a siphon and be back at your car before your friend returns from his shopping at the mall. Too bad you missed him! You can catch up with him later.

Apparently the siphon is a pretty old invention. Men had been draining their bilges and borrowing from their neighbors supplies for thousands of years with this great tool. As long as A was less than B, men were free to borrow as they wished. The thinking - and its easy to see - is that since there was more liquid on the B side, it would pull ( or "suck" the liquid from the A side as liquid B fell due to gravity. The theory relied on the fact that "Nature Abhors a Vacuum". The liquid on the A side would rush to fill the empty space left by the falling column of liquid on the B side.

They saw no limit to the borrowing, and envisioned borrowing entire lakes from their friendly neighbors on the other side of the hill. Somebody tried this one day, and were astonished to find that the siphon did indeed have limits. They couldn't get a siphon to work if the height of the obstacle they were trying to overcome was more than 33 feet. Can you imagine this as a real mystery? Try it. It had people baffled, and they never really quit trying. It didn't make any sense. They tried again, and again.

Anway, Pascal, at the typical young age of a super genius, demonstrated that the air had weight. The equivalent weight of all the atmosphere, pressing on the top of the gas tank on your friends car was the "weight" of a column of water 33 feet tall. It is the weight of the atmosphere pushing the column of liquid on the A side, and really nothing to do with the B side at all, that makes a siphon work. No sucking, just pushing. Sound familiar, Toot?

I'll bet you just knew I was itching for an excuse to drag that one up from the depths!

Blaise Pascal
1623 - 1662

We are usually convinced more easily by reasons we have found ourselves than by those which have occurred to others.
Pensées



I hope you enjoyed reading that as much as I did typing it.

Mike

 

As a matter of fact, yes it does sound very familiar...

You're talking about my exgirlfriend, right?

 

Thanks Bilgeboy, that was a good read!