Hydrostatic Testing For Waste Oil Tank

Hello Ballasttank26, In essence what hydrostatic testing is, a tank, plumbing or other enclosed combination, that is filled with a Non-flammable non-compressible liquid in a closed system. Then pressurized to an engineered specification. In your example time is included so what your looking for is any leaks be either liquid or gas escaping from the closed system that allows the pressure test gauge to drop from the set point in the time allotted.

Being this is a military job there should be guide lines in proper setup and testing.

hope this helps Charles

Just an enquiry: Need some information - If someone ever heard of Hydrostatic Testing for Cable Cores of subsea umbilicals cables?

You will normally test the hydraulic cores. There should be a procedure available. The cables will need to be able to withstand external water pressure at depth but this is not normally seen as a problem

Thanks - but I need to know further on the testing procedures; and can anyone on this site direct me to a company that can offer this type of "off the shelf" testing pressure vessel or systems? I would really appreciate it. Kind regards.

This will involve isolating the tank and connected pipework and sealing, prior to inserting the water and test pressure. Water should be put in the tank to virtually full then air put in to the required test pressure, but check the test pressure plus liquid head pressure will not overstress the tank.

The gauges used should be calibrated to a known and accepted standard. Allow for temperature compensation when checking for pressure drop. During the period of test check all connections regularly for leaks, including the gauge connections. Soapy water brushed on the joints will show any leaks by formation of air bubbles. The EPA have procedures for testing, check their website.

NO!!!!! NEVER EVER use air as the pressurization medium!!!!! Air is compressible and if the tank were to fail catastrophically you will have created a bomb. The goal is to REMOVE as much air or other compressible gas from the system as possible.

Hey Prof,

Right on the head technically, though i would say 'The calibrated pressure gauge should be .......'

Thanks - that's exactly what I think that I thought I had said - I think . Yes - gauge, definitely gauge.

thank you all for your help

one last thing, what are the items i should prepare for the hydrostatic test?

Ask the US Navy Engineer of Record to provide you a copy of the Hydrostatic Pressure Testing Procedure since they issued the Contract Documents (including Technical Specs). They ought to have a copy handy to give to Contractors, or you may find the procedure in the DIPRA Handbook online (ditto w/ the older CIPRA Handbook).

DIPRA= Ductile Iron Producers Research Assoc.

Also, check the US Army Corp of Engineers (USACE) Guideline Specifications and Engineering Manual for the pertinent Tech Spec regarding performing Hydrostatic Pressure Testing.....they are available online......using an Army spec should really rankle the Navy personnel who should have issued the testing procedure in the Project Manual or as an Addendum Item!

or,

Issue a Request For Information (RFI) to the appropriate US Navy office (Engineer of Record) supervising the ship refit.

Good luck with your project!

Ask any of the Navy personnel for a copy of the Joint Fleet Maintenance Manuel (JFMM) volume 5 (Quality Maintenance) chapter 7 (testing Requirements) (I'm not sure of the sub chapter on Hydrostatic tests, think it is 7.5). This will explain how, and reference you to all the documents you will need. (20 years served in the Submarine Force...) Good Luck.

Let me clarify... All Navy ships having work performed by outside contractors liaison with a Ship's Sup or the ships 3M coordinator. Find him!!! He knows exactly what the requirements are. It is his responsibility to ensure the work is done correctly and on time. He will use the JFMM vol. 5 as a guide. He will help you identify your boundaries in the ships waste oil system. He will help you identify system gauges that can be used for the Hydrostatic testing. He will show you on the ships prints the "H" and "J" pressures. He will tell you how to do alternative testing for areas that can not be tested with a normal hydrostatic tests. He will show you the time on the prints to hold the test pressure to, and if it needs to be brought up in increments. He will have the documentation that you must sign off. Along with the associated documentation for your test rig or source of pressure, and the gauges and reliefs to document the test. He will show you how to calculate the set points of your relief valves to ensure you do not over pressurize the system. He will coordinate with the ship and get the approval for you to do the test. Use him, abuse him, he is there to make your job run smooth, on time, and hopefully under budget.

Hello Cross QA, Here an online home page to JFMM Home Page. With download for offline use.

Hope this helps Charles

Good morning Ballasttank26.

Completely isolate the discharge piping, by capping or spading. Allow air to escape from the high point or points. Install an air bleed nipple & (air) valve at the highest point, along with fittings for test water and recorder attachment. Now install nipples and a (water) valve to connect your test water. If the required 68 psig test pressure cannot be achieved with available water pressure, do so with a N2 bottle, then close the (water) valve, remove the N2, and cap the nipple.

After filling with water & purging of all air, close the air valve and install a 24-hour paper recorder. Open the air valve. 68 psig should register on the recorder.

Come back in 24 hours. If the paper chart shows the pressure varied but returned to the initial 68 psig, you have no leaks. If it drops but does not come back to 68 psig, find and repair the leak, and retest. Note: your client may allow you to use 30 minutes.

Repeat on the suction piping, using the required 50 psig. Submit the sucessful paper test charts to your client as proof of the inegrity of the systems.