Hydraulic pump leak detection.

Question

Hydraulic pump leak detection.

tactical14 (Mechanical)

(OP)

13 Apr 12 15:07

Just wondering if anyone has any experience with this?  The company I am working for currently dunk test their pumps in water to check for leaks.  I think dunk testing is a good, quick test, but it absolutely terrible for our application, as water and hydraulic systems don't get along.  Some current methods of leak detection I am looking into are:

Pressure Decay testing, which is very good, but very expensive.  And ultrasonic leak detection, which is fairly cheap, but I keep reading mixed reviews.

Does anyone have any experience with these two methods?  Any insight is greatly appreciated.

hydtools (Mechanical) · Answer 1 · 2012-04-13 17:45:07

What is the test fluid?
Why do you think water and hydraulic systems do not get along?

Ted

btrueblood (Mechanical) · Answer 2 · 2012-04-13 18:39:58

The only reason I could surmise from the comment "water and hydraulics don't get along" is if the pump case is corroding after being dunked and/or the pump internals are exposed to water and similarly corroding.

One could:

- add corrosion inhibitor to the dunk tank water.
- Add a step to air blast water off the pump before disconnecting the pressurization fittings.
- immediately place the tested parts into a warm oven/air blast dryer, or heated vacuum chamber, to speed drying.

Doing all 3 would probably reduce corrosion concerns to zero.

btrueblood (Mechanical) · Answer 3 · 2012-04-13 18:41:37

Going further, you could also dunk the pumps into a bath of light oil...

or use a helium leak tester...

tactical14 (Mechanical) · Answer 4 · 2012-04-16 08:15:47

Let me go a little more in depth.

We build the pump then attach fittings and plugs to make it air tight. Then we connect air at ~ 15 psi and dunk it in a tank of water with a rust inhibitor. Once that is completed, the excess liquid is blown off the pump and then the pump is tested and set at the customers specifications.

Our main concern is somehow introducing water inside of the pump, which will cause a lack of lubrication between mating surfaces and eventually the pump will score.

So I am just wondering if anyone has experience with leak testing and have offer any good insight.

hydtools (Mechanical) · Answer 5 · 2012-04-16 09:49:56

Your final test and setting process will fill the pump with lubricating fluid and leave a lubricating residue. We tested parts with nitrogen and the part dunked in solvent and looked for bubbles.
Check for leaks with the same setup used for testing and setting the pump. Skip the water dunk test if it is too much of a concern.

Ted

kcj (Mechanical) · Answer 6 · 2012-04-16 10:13:07

This might not meet your goals on the suction side, but could you add Spectroline leak detection to the fluid used on the test stand, then use the UV light detection for leakage when the pump is under pressure testing? Or do you need to detect leaks before hooking it up to the test stand?

kcj

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Hydraulic pump leak detection.