What does 'flogging the bolt' mean?

[vesselguy]

Hi,
Some of the older guys might be able to tell me what does it mean when someone say, 'flogging the bolt' is not permitted? Seriously.

 

[Artisi]

In what context is it being used?

 

[vesselguy]

Artisi,

I am reading a company standard on flange bolt up proceedure and torque values when I came across this unique term that I have never heard of. I gogled and have not find any definitions for it. This must be a very old term used by the older guys.

 

[rb1957]

given that i suspect it means overloading the bolt, particularly in preload

 

[TGS4]

I would guess that it means that using a hammer-wrench is not permitted. (As an aside, I used one (hammer-wrench) my first summer job - I was bolting up manways for free-water knockout drums. My shoulders were so sore from swinging the sledge hammer onto the hammer wrench. And the vibrations that traveled back through my body - oy).

 

[vesselguy]

TGS4,
You might be right because this term is used in a section where it talks about tightening methods - convential spanners/wrenches. It said, "the flogging of bolts in hydrocarbon system is not permitted."

So it might mean, like you said, the action of swinging a sledge hammer to apply impact load onto a spanner wrench to develop torque.

 

[hydtools]

Looks like flogging a bolt or nut is done with a sledge hammer and flogging spanner.

http://www.valvecare.com/FlangeHire.htm

Ted

 

[IRstuff]

His invention, the Hydranut fastener, is a new and better way of tensioning large nuts than "flogging" the nut using a ring spanner and sledge hammer. Although hydraulic nuts are nothing new, the few models on the market were either for permanent installation, required specialised equipment for hydraulic charging or were very elaborate and expensive.

from

http://apc-online.com/twa/manufacturing2.html

TTFN

FAQ731-376

 

[vesselguy]

Thanks everyone for your reply. I think we now know what 'flogging the bolt' means. We should all be kind to our bolts and let's not flog them anymore. We'll just keelhaul them instead. LOL.

Thanks guys.

 

[ivymike]

I protest. I think I'm going to go flog a bolt before I log off.


maybe too close to the edge there (must resist nut joke)

 

[unclesyd]

vesselguy,
You are pretty close in the reference to the naval practice of keel hauling as the term "flogging" seems to have originated in Great Britain. I believe the original term was "flogging spanner".

I got into deep trouble when I substituted a Swench for a ring spanner (hammer wrench) to remove turbine housing nuts. The hammer wrenches were supposed to be used with extensions. We were not to use hammer (flogging) wrenches on said nuts under any circumstances.

http://www.powerhawk.com/pages/SWENCH/1000.html

 

[rmw]

My British colleagues use the term "flogging wrench" while my American colleagues use the term "slugging wrench". Same tool, same hammer, same process, different terms. We are two countries separated by a common language.

rmw

 

[katmar]

Maybe it is because I am old, maybe its because I am in South Africa, but the term "flogging spanner" is one that I have always heard and used. I think rmw has hit (flogged?) the nail on the head when he says we are separated by a common language!

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[chief]

Captain Bligh, "Flog that man".
Mr.Christian. "But he is dead Captain".
Captain Bligh, "Then flog his belongings".

Offshore Engineering&Design

 

[rconner]

While I have obviously been some sheltered and have not heard this particular term, in reading the definitions/responses in this thread I must however now admit I have seen a few large bolts "flogged" before over the years. This type of hammer wrench tightening was used in places where e.g. equally simple tools "cheater bars" could not be used, particularly when bolting in very tight quarters, and presumeably when more fancy or expensive tools like torque multipliers etc. were not available. While I should explain none of this was in hydrocarbon service, I have however seen this technique used to stop leakage out of large water etc. flanges (leakage was apparently due to initially inadequate or otherwise imperfect assembly/torque procedures). I thus suspect this technique is capable of establishing effectively quite high levels of "torque" or bolt tension (and some accompanying gasket compression).
I was just curious what references or negative experience others might have that would form the basis of a prohibition for at least a gradual workmanlike application of this bolting discipline in a specification (I realize of course this practice obviously creates more shock to the bolting etc. steel, but I have personally not witnessed any "pop") .

 

[chief]

I worked on many slow speed marine 2-stroke Diesel engines (100rpm) in the days before hydraulic torqueing equipment was available.
The bolts could be up to 6"dia and were flogged up by sledgehammer (flogging hammer). The practise was to pop punch the bolt and nut postions before dis-assembly and then flog up to the same or thereabouts position when assembling.
I ended up with a physique like a weight-lifter along with my sailors roll. We loved it and there was always a queue to get the flogging hammer.

Offshore Engineering&Design

 

[limey1]

Back in the 80's I worked as a Diesel Fitter for a Bus company in Liverpool, England. We would rebuild the rear suspension leaf-springs and part of this was to fit u-bolts into the axle. Coarse thread nuts would be tightened with a flogging spanner. It was a lengthy and physically draining job, but i was definately leaner than I am now sitting here writing this!!

 

[vzeos]

Rconner,
Slugging has long been quite common in the natural gas pipeline field used to make up tight flange joints. There are now high torque pneumatic wrench drives that make slugging unnecessary.

Slugging can be a problem when used on bolts because the impact of the hammer will tend to shear off the bolt head or, even worse, create a flaw at the shoulder of the bolt such that the bolt will fail in service. For this reason, flange connections in the gas industry are always made using high strength studs and high strength nuts. Never bolts.

 

[rconner]

Thanks, vzeos for the explanation [come to think about it, I think I probably somewhat miswrote as I believe it was really the nuts, as on a threaded bolt end or stud,that that I've (seen) "flogged"!]

 

[vesselguy]

I think we have been "flogging" this to death by now. LOL.


Really, it is nice to see a light hearted discussion on this site for a change.