Dear Christoph and Kris,

Thanks for your inputs to the Wikipedia article on vacuum trucks!
Christoph, it's OK to modify the content even if you don't have a reference at hand for each statement. I think it's OK for such practical topics like vacuum tanks (it would not be OK for health related content as Wikipedia is stricter there). If needed, one can always add the {{citation needed}} tag, too.

Anyway, so I have changed the lead section as per your suggestion, it is now:

en.wikipedia.org/wiki/Vacuum_truck

A vacuum truck or vacuum tanker is a type of tank truck that has a pump and a tank, designed to pneumatically suck liquids, sludges (such as fecal sludge), slurries or sand/water mixtures without the contact of any mechanical equipment. They are used to transport sanitary waste (human excreta mixed with water, e.g. from septic tanks) as well as for some industrial liquids or slurries. They can be equipped with a high pressure pump if they are used to clean out sewers from sand.
Vacuum truck are used to transport the collected material to a treatment or disposal site, for example a sewage treatment plant.

The other things that you mentioned have also been changed, partly by Kris, partly by me. However, I got a bit lost in the part about the typical maximum lift. Could you please take another look (also addressing the question that Kris asked in his post before this one?).

If it's easier then just go ahead and make the edits in the Wikipedia article (or explain to me what needs to be changed).

Thanks a lot! I am learning a lot about vacuum tanks by trying to clarify these things about lift and suction hose length etc.!

Regards,
Elisabeth

christoph wrote:

“There are two different ways to mount the pump: either directly on the truck with the vacuum drive powered by the truck motor, or on the trailer with an independent motor. The more complicated trailer mounted version allows the utilisation of both the negative pressure suction side of the pump as well as the positive pressure side to pump sludge over longer distances or lift it higher into the tank.”

The observation is not correct. It is possible to pressure the suction side of the pump as well when powered with the truck motor. Actually I hardly know Vaccum tanker with a pump on a trailer I would say that is less than 5% of the cases.

Yes it is quite uncommon, as with a air vacuum pump it is difficult to build a setup that can also push. Of course technically you can have the same on the truck (for quicker emptying for example), but that wouldn't really increase the possible lift more than maybe a meter difference between the motor and the top of the tank, no? So practically speaking the text in the wiki (which I wrote) is correct, as the point of having it on a trailer would be to move the pump closer to the septic-tank and thus reduce the length and hight-difference of the suction hose. Or am I misunderstanding what you meant?

christoph wrote:

“Due to the inherent suction limitations of all suction pumps, that can only lift a liquid through atmospheric pressure, a theoretical maximum water lift of approximately 10.3 m (33.9 feet) can be reached.[4]“

That is not correct. It should be.

The typical maximum lift depends on the equipment (vaccum pump) and the material to be transported. The mixture of water/sludge and air (to be controlled by the operator) reduces the density of water/sludge and a theoretical water lift above the clean water lift limit is possible. In practical operation lift differences of over 15 m will seldom be possible. This limits as well the length of the hose. Only in limited cases a hose larger than 50 m will be used.

Can you explain that a bit better? Am I guessing right that the higher density of the sludge solids is not so significant, so that by adding air into the mix the overall density of the sludge/air mix can be brought down significantly below that of pure water?
I always thought adding air was only a way of offset other losses, not actually to increase the overall lift above the theoretical limit of water.
Edit: I changed the text a bit to explain this better. However I also don't have a good source for this.

Dear Elisabeth,
I don´t have the references on hand, therefore I did not change anything in Wikipedia. I try to put some aspects here from the page so that you can use or discard them without changing Wikipedia

General

A vacuum truck or vacuum tanker is a type of tank truck that has a vaccum pump and a vaccum tank, designed to pneumatically succion liquids, sludges (such as fecal sludge) or slurries or sand/water mixture without the contact of any mechanical equipment. They are mainly used to transport sanitary waste (human excreta mixed with water, e.g. from on-site septic tanks) as well as for some industrial liquids or slurries and equipped with a high pressure pump they are used to clean out sewers from sand.
The material has to be transported to a treatment or disposal site.

In the text

Pumps:

“There are two different ways to mount the pump: either directly on the truck with the vacuum drive powered by the truck motor, or on the trailer with an independent motor. The more complicated trailer mounted version allows the utilisation of both the negative pressure suction side of the pump as well as the positive pressure side to pump sludge over longer distances or lift it higher into the tank.”

The observation is not correct. It is possible to pressure the suction side of the pump as well when powered with the truck motor. Actually I hardly know Vaccum tanker with a pump on a trailer I would say that is less than 5% of the cases.

Suction lines… Better .. suction hoses?

“Due to the inherent suction limitations of all suction pumps, that can only lift a liquid through atmospheric pressure, a theoretical maximum water lift of approximately 10.3 m (33.9 feet) can be reached.[4]“

That is not correct. It should be.

The typical maximum lift depends on the equipment (vaccum pump) and the material to be transported. The mixture of water/sludge and air (to be controlled by the operator) reduces the density of water/sludge and a theoretical water lift above the clean water lift limit is possible. In practical operation lift differences of over 15 m will seldom be possible. This limits as well the length of the hose. Only in limited cases a hose larger than 50 m will be used.

I hope that helps a bit.
Regards
Christoph

muench wrote: Could you please help me by telling me what I should write there for:

• Maybe a sentence on the maximum typical lift (and related maximum length of suction hose) could be included as that seems to be a practical question that comes up now and then?
• The pump capability (height and distance limits) would certainly be good information to include

I made some small additions and changes to the article, however I came to realize that explaining the above in the detail necessary (type of pump, strength of vacuum, type & size of suction hoses used etc.) would probably be outside of the scope of this article.

Dear Kris and Andrew,

Thanks for your responses to my question about the vacuum truck article on Wikipedia. I have taken your suggestions on board and modified the article accordingly, please see here:
en.wikipedia.org/wiki/Vacuum_truck

The lead section still needs to be built up again (as it's the lead section that is shown in Google's search results box, and which first gets translated into other languages)

Could you please help me by telling me what I should write there for:

• Maybe a sentence on the maximum typical lift (and related maximum length of suction hose) could be included as that seems to be a practical question that comes up now and then?
• The pump capability (height and distance limits) would certainly be good information to include

Andrew: please check if all the important industrial uses for vacuum tanks are now well covered in the article?

Note there are also related articles:
Suction excavator: en.wikipedia.org/wiki/Suction_excavator
Gully excavator: en.wikipedia.org/wiki/Gully_emptier

There seems to be quite a few similar vehicles around.

Regards,
Elisabeth

I agree with Krischan, the terms are interchangeable. I can imagine that some people consider vacuum tankers to be be bigger than vacuum trucks but that's more of a personal use issue.

I think the description shouldn't be limited to fecal sludge pumping. The trucks are used for a variety of industrial application.

The pump capability (height and distance limits) would certainly be good information to include.

Cheers,

Andrew

I don't see a difference between a "vacuum truck" and "vacuum tanker"... two different ways to describe the same thing, no?

The definition itself should probably include the most typical use-case in the first sentence, i.e. emptying of septic tank sludge. The exact diameters of the pipes or the exact type of vacuum pump seems less important though.

Maybe a sentence on the maximum typical lift (and related maximum length of suction hose) could be included as that seems to be a practical question that comes up now and then?

Have you ever thought about how you would describe in simple terms what a vacuum truck is? And what is the difference between vacuum truck and vacuum tanker?

As a layperson, many people would check here on Wikipedia:
en.wikipedia.org/wiki/Vacuum_truck

The first paragraph (which is the so called "lead" and is very important) describes it like this:

A vacuum truck or vacuum tanker is a tank truck with pump designed to pneumatically load solids, liquids, sludge or slurry through suction lines typically 2 to 4 inches (5.1 to 10.2 cm) in diameter with 3" or 3 inches (7.6 cm) being the norm. The typical pump used is the rotary vane vacuum pump. The truck can be configured to be a direct belt drive, or a hydraulic drive system. There are two different ways to mount the pump: either directly on the truck with the vacuum drive powered by the truck motor, or on the trailer with an independent motor. Each application has different handling characteristics.

Vacuum trucks which collect fecal sludge usually have a volume of 10 - 55 cubic metres.[1] They generally use a low-volume sliding vane pump or a liquid ring pump.[1]

(the last two sentences were added by me today. Reference 1 is the FSM book by Sandec).

However, I am not that satisfied with this explanation. Is it really correct? Is it easy to understand? And is it true that a vacuum truck and a vacuum tanker is the same thing?

I checked in the Sandec book on FSM but didn't find a satisfying definition. The book also has no glossary. (www.eawag.ch/en/department/sandec/publik...management-fsm-book/)

Regards,
Elisabeth