How to know what is the failure in a hydraulic group? 1

[vicasazn]

Hello,

I am non native english speaker but I will try to do my best.

Is there some procedure to know if the pump is going wrong in a hydralic group??

For instance close the valves and start the pump to check the electrical consumption, or check the maximun pressure...

Thank you in advance

 

[hydromech]

You need to state the problem first.

What is not happening that should be happening?

What part of the system was working, but now does not work?

 

[vicasazn]

Hello Hydromech,

It would be a drop in the working pressure, so I would be interested in knowing a way to discard another parts and to confirm that the problem is the pump.

I remember we had a problem and somebody told us to close the valves and to check the maximum pressure the pump was able to reach... Finally we changed the pump and this was the problem but I like to know a systematic way to indentify this specific problem...

Thanks.

 

[hydtools]

Try this company's suggested troubleshooting steps:

http://www.hydraulic-systems.com/pages/ref_main.htm

Ted

 

[MikeHalloran]

You can't just arbitrarily close whatever valves you find in an arbitrary hydraulic system; doing so risks damaging the system, and also risks injury or DEATH to yourself or innocent bystanders.

As hydromech alludes, you have to record what that particular system is doing or not doing that is undesirable, and use knowledge of the system's design to infer a root cause and fix it.

... or pay someone who has the knowledge to do so.





Mike Halloran
Pembroke Pines, FL, USA

 

[hydromech]

Simply closing random valves to load the pump is like putting a wet finger a plug socket to check if the power is on...high chance of mortality, or even worse, multiple mortalities!!!

You need to pay for a skilled engineer to look at the system.

You might get lucky and fix the problem, equally, you might do more damage to the system of hurt someone.

 

[EngineerTex]

I think what vicasazn may be referring to is a method that is not uncommon for determining a pump's efficiency.

The general method is to use an adjustable relief valve and have 100% of the flow of the pump go into this valve. Slowly adjust the pressure on the relief valve up to the pressure rating of the pump and then take two measurements: 1 - the flow feeding into the relief valve and 2 - the flow coming out of the case drain of the pump. By taking a ratio of the pressurized output divided by the sum of the case drain flow and the pressurized output, you can determine the pump's efficiency.

HOWEVER: as is stated above, this is not something to be undertaken unless you've got the proper measuring equipment, properly calibrated relief valves and all sorts of other proper safety equipment.

Also, keep in mind that if you are running the pump at a speed below its rated speed, you may end up with incorrect results as they relate to pump efficiency.

Engineering is not the science behind building. It is the science behind not building.

 

[EngineerTex]

I realized that I overlooked something important in my reply above. The port-to-case leakage can be accounted for with the method I outlined, but the port-to-port leakage cannot be measured in this manner. This is an important factor to be considered when calculating pump efficiency, but is not going to be determined unless you know the exact displacement per revolution vs. the flow rate at the speed you are running the pump. This is why it's best to bench test each pump when it is new and develop a program of routine testing to determine when they need to be replaced.

Engineering is not the science behind building. It is the science behind not building.

 

[vicasazn]

Hello,

I meant exactly Hydtools´s link; a systematic (step by step) procedure to identify the origin of the failure.

Excuse me for my bad way to express but I don´t remember exactly How it was...

I remember the external engineer wanted to know if the pump was able to reach 2250 psi (150 bar).

Anyway very easy and clear the troubleshouting guide.

Thank you