Ultrasonic testing galvanized tanks

[guruboy]

found a re-qual (hydro) shop near me that uses ultrasonic testing.

Does anyone know if there is any reason why ultrasonic testing is not compatible with hot-dip galvanized (Worthington, PST) steel tanks?

 

[michael-fisch]

Believe that ultrasonic testing is only used to find cracks (breaks) in the tank material, a common problem with older aluminum tanks.
It cannot find thinner areas in steel tanks caused by rusting of the steel, which is the main reason why steel tanks can fail a hydro.

Michael

 

[guruboy]

Ultrasonic testing can detect thinning areas

See the FAQ here-
Ultrasonic Examination (UE) | FIBA Technologies, Inc.

 

[captain]

If the thinning is due to rust it would would be visible upon visual inspection. The method of manufacture does not produce an even wall thickness. That is why the average of several thickness tests is used when calculating cylinder strength.

 

[JamesBon92007]

This is all very interesting. So, they can now tell if a tank is OK just by looking at it instead of actually pressure testing it? Is this going to increase the cost of the five-year test (formerly known as hydro-test)? Do they even need to take the valve off and empty it, or is a visual inspection still a requirement?

 

[runsongas]

only if corrosion from wet fills is suspected. UE usually costs more because the equipment isn't cheap for initial setup and the customer (usually industrial) is willing to pay a premium to avoid valve removal/redrying of the cylinder.

 

[guruboy]

Unfortunately the UE shop I was considering only does 3AL and 3AA tanks. They did not have the calibration for any of the SP/E tanks.