What's a "Hammer Test"?
What's a "Hammer Test"?
(OP)
I've seen a couple of drawings of older pressure vessels (WWII era, IIRC) that mentioned the phrase "Hammer Test" in the section that listed all of the NDE. What kind of test could this be referring to?
-Christine
-Christine





RE: What's a "Hammer Test"?
It was and is used to test for broken stay rods in vessel, especially a boiler or heater. You have to have access to both end of the stays. You watch the rebound of one hammer to the impact of the other hammer it takes hammers.
RE: What's a "Hammer Test"?
RE: What's a "Hammer Test"?
My older copies of ASME VIII call for the pressure to be lowered to MAWP before whacking on it with a hammer.
Steve Braune
Tank Industry Consultants
www.tankindustry.com
RE: What's a "Hammer Test"?
The test procedure for a vessel stay rods was test a 0 prssure, note bad or funky stays, then pressurize to 1/4 of the MAWP and retest.
Anecdotal:
The newest man in the shop got the hammer.
In the early 50's and again in the early 60's I go to see a variation of the hammer test being used to test full size vessels made for Nickel Steels filled with LN2. They did take the man out of equation.
Not too long ago we decided to test a jacketed SS vessel with stay rods to ascertain if we could detect potential leaks. I was the inside man and on the third try one of the stays tore loose with loudest bang the earth has ever heard. Even with sponge ear plugs my ears rang for several weeks and it was a week before I could hear anything.
RE: What's a "Hammer Test"?
Highly technical.
RE: What's a "Hammer Test"?
RE: What's a "Hammer Test"?
RE: What's a "Hammer Test"?
There are several hammer tests with the one that Christine74 was concerned with was to test the integrity of the welds and heat affected zone of mainly newly fabricated or repaired vessels. The hammer use was the aforementioned 16# pounder or larger.
The test you mentioned was usually referred to as "ringing" the metal whether rivets, stays, or tie-rods. We also used the smaller hammer to survey for fire damage (burnt metal) to determine further suitability for for service. The type test you mention was a must in the railroad round houses for in service locomotive boilers. It was also used on some tank cars. Anything riveted was candidate for a few whacks
The LN2 vessel I saw under test at temperature was hit with a very large weight dropped several feet. There were 2 vessels one was impact tested and the other test to failure at temperature.
RE: What's a "Hammer Test"?
RE: What's a "Hammer Test"?
genb
RE: What's a "Hammer Test"?
Must comment----if the wall is thinned to half the t-min. you may be doing a service to "hole it". Sounds like a good way to avoid some unnecessary death.
Check some of the old stds.for A-139,spiral weld pipe. "Strike weld with 3# hammer under full hydro".I don't see it in there anymore,must of ran out of employees.