selection of suitable pump for gasoline lifitng 1

[mirghaffari]

Dear Sir,
i want to select the suitable pump to lift the gasoline from the Truck. the truck is located 3 meters under the platform that pump is located on it.
we try with gear type pump (that used in gas stations), but the result is not good becuse of very low flow. we can not used check valve in suction line becuse we have to drain all remaining fuel to truck and start this process with next truck. could you help me to select the suitable pump that can prime in short time?

best Regards,
mirghaffari

 

[mirghaffari]

Excuse ne my dears,
Our plant and our target is very simple ( as shown in schematic). We want to lift a liquid(oil, gas oil, gasoline,...) from the truck for sampling and its qualificatin.
For this porpose, we have to lift the liquid with PD pumps. The distanse between pump and top of liquid level is around 3 meters. We instal the pump and start it. The pump lift the liquid correctly but after 30 secends the flow decress to zero!
Wen we shout down the pump and start again, the pump work again for 30 secends!
Do you know why?
The flow rate is not important becuse wevneed only one liter for sampling, but we have to circulate the liqid in our piping for around 3 minets to clear the piping from previous remaining oil (that may be remain from previous truck). But unfortunatly our pump works only 30 secends!
I think the vapor traps in pump and do not allow the liquid to flow!
This is my guest! What about you?
If i am right, could you help me how can solve this problem?

Regards

 

[LittleInch]

Ok. Please draw the entire system. I still don't understand why you just don't drop a sample can in...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[bimr]

The application is too hazardous to answer with such brief information. Sampling and gauging operations if not done properly can introduce spark promoters into the tank truck.

 

[georgeverghese]

Could you use an eductor to lift a small flow of this liquid up - No NPSH issues then - you'd have to use some inert gas ( like MP nitrogen ) and install a vapor- liquid separator d/s of the eductor.

In the case of gasoline, you may lose some light ends may migrate into the vapor phase - does that matter in this case ?

 

[georgeverghese]

Another alternative would be to use an air operated DD pump - Wilden or similar - these can handle intermittent dry suction. This would be easier to install too compared to a N2 powered eductor - you could use compressed air for this provided a leak sensor is included. Off the shelf item in most countries.

 

[mirghaffari]

Dear sir,
thanks for your good cooperation and helpful files.
1- Mr.LittleInch : we can not put a sampling cap in to the truck because we want to lift the liquid from different location and also different liquid level. for example water is heavy that gasoline and deposit in bottom of tank. with pump we can lift the gasoline from different points.
2- Mr. bimr : for safety we try to use flexible non metal hose to avoid spark.but we use this helpful file.
3- Mr. georgeverghese : thanks for your proposal. could you please give me more information regarding this air operated DD pump?
4- Mr. georgeverghese : small sampling is not our target. because before sampling we have to circulate the liquid in our sampling pipes to clear the remaining previous ;liquid in our piping. after that we open the sample point to get one liter liquid for laboratory. you are right, we have a lot of vapor in discharge of pump. because we vacuum the air in top of the liquid level for lifting and it cause the liquid be vapor. our main problem is this. i think this vapor can not totally vent from the pump and trap in pump casing and don't allow the liquid to flow (i think and i am not sure). i am seeking for a solution to select the pump that can work with this situation or a way that vapor can vent from the pump easily.

thanks alot

 

[georgeverghese]

Here is the link for a Wilden pump supplier - the supplier in your country may be some other sales company

https://www.allpumps.com.au/brands/wilden

And the link for a similar Sandpiper pump

http://www.sandpiperpump.com/

Good luck