Previous in Forum: Need Info for a Integral Hydraulik Unit   Next in Forum: Ergonomics
Close
Close
Close
58 comments
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202

Water Pump "Explosion"

08/07/2013 9:28 PM

How is it possible for an operating industrial water pump to blow itself up? Please no dynamite, C-4, M-80's, ANFO, TNT, PETN, RDX, Nitro Glycerin, Detasheet/Flex-X, IED's, Detcord. etc. Just water and the pump.

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Pathfinder Tags: explosion pump Water
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Mar 2012
Location: Out of your mind! Not in sight!
Posts: 4425
Good Answers: 107
#1

Re: Water pump "explosion"

08/07/2013 9:34 PM

Master of all known explosives. I am not sure there is not something missing like flour in your list, but since you specified water and pump I am going to ask a question:

Positive displacment pump???

The most important information would be what your set up was! A blockage in the outlet would amount to a seriously dead pressure in the system if the safety valve does not work the pump will blow up!

Back to you!

__________________
Common Sense Dictates
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#2
In reply to #1

Re: Water pump "explosion"

08/07/2013 10:15 PM

Not "Master of all known explosives". Years ago I spent a week at New Mexico Tech in Socorro. Very Interesting, got a bang out of it!

It can happen with a pos disp pump but not necessarily the only type.

Set up is a common type. Valve, union on inlet. Pressure Relief Valve, union, gauge, and valve on the outlet going to further down the piping.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru

Join Date: Mar 2012
Location: Out of your mind! Not in sight!
Posts: 4425
Good Answers: 107
#8
In reply to #2

Re: Water pump "explosion"

08/08/2013 1:35 AM

Pumps can go with a bang. Positive displacement pumps probably when the safety device does not work, is obstructed or disabled and the fluid pressure can do its work.

Other than that a bolt that gets stuck in the rotor of a centrifugal pump can rupture the case. What pump are we talking about?

Could you post a picture of the pump. Would be nice to see an exploded pump!

__________________
Common Sense Dictates
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 20964
Good Answers: 780
#3

Re: Water pump "explosion"

08/07/2013 10:44 PM

Maybe the relief valve stuck closed, or was obstructed by debris.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#4
In reply to #3

Re: Water pump "explosion"

08/07/2013 11:07 PM

What effect would that have and what mechanism for the explosion?

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 20964
Good Answers: 780
#7
In reply to #4

Re: Water pump "explosion"

08/08/2013 12:15 AM

Are you serious? Do you really have to ask a question like that?

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#23
In reply to #7

Re: Water pump "explosion"

08/09/2013 12:49 AM

No I don't but others might gain from your knowledge.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 30310
Good Answers: 817
#9
In reply to #4

Re: Water pump "explosion"

08/08/2013 3:14 AM

The stress introduced by the effect of the spinning rotor exceeded the yield stress at the weakest part of the casing, perhaps?

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply Score 1 for Good Answer
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 30310
Good Answers: 817
#57
In reply to #4

Re: Water pump "explosion"

08/12/2013 5:45 AM

OK. How about - the settings of the circuit protection devices exceeded the value needed for safe disconnection of the motor during an overload?

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply Score 1 for Good Answer
Guru

Join Date: Jun 2013
Location: Central Canada
Posts: 677
Good Answers: 28
#58
In reply to #57

Re: Water pump "explosion"

08/12/2013 2:41 PM

What if they started pumpin Heavy water ?

__________________
Smart as a post and twice as fast.
Register to Reply Off Topic (Score 5)
Guru
United States - Member - New Member

Join Date: Mar 2010
Location: In the pool because it is too hot.
Posts: 3055
Good Answers: 140
#5

Re: Water Pump "Explosion"

08/07/2013 11:33 PM

Didn't read it in the papers.

Explosion because of more pressure than the housing could withstand or something not on the list in the water?

__________________
Plenty of room here
Register to Reply
3
Guru

Join Date: Jun 2009
Location: South of Minot North Dakota
Posts: 8378
Good Answers: 774
#6

Re: Water Pump "Explosion"

08/07/2013 11:52 PM

On possible theory, if it is a centrifugal type pump, is that the impeller self destructed and parts of it jammed between its remaining spinning core and the body causing a catastrophic mechanical failure.

Given a higher RPM pump with a large motor and rotating mass there would be more than enough stored energy to give the effect of the whole unit appeared explode when the impeller came apart and jammed plus once the unit did blow itself a part the source of the failed part of the system may be very hard to identify.

It would be sort of like trying to find where the hole was that caused a car tire go flat and shred itself after it shredded itself leaving too much shredded wreckage to identify the actual source of the initial failure.

That or my wife was there and she ran it out of gas one time too many.

Register to Reply Good Answer (Score 3)
Power-User

Join Date: Aug 2010
Location: Wales, UK
Posts: 387
Good Answers: 18
#10

Re: Water Pump "Explosion"

08/08/2013 3:35 AM

Hi old salt,

It's the same as in hydraulics, if there's enough Horse Power going in and nowhere for it to go, "BOOM" pump case splits (or worse).

Best regards,

John

__________________
Best advice I can give as you get older "Never miss an opportunity to relieve yourself"
Register to Reply Score 1 for Good Answer
Active Contributor

Join Date: Apr 2012
Location: Oklahoma City, Oklahoma USA
Posts: 14
#11

Re: Water Pump "Explosion"

08/08/2013 7:57 AM

Some of the answers given are possible, but probably are not the cause. When your designing a hydronic system one of the first things you consider is expansion of the carrier solution (Water/Glycal) and in the middle of your design is a simple preset air valve usually (125 psi) most of which are adjustable. it maintains the constant in your hydronic system, this is what needs to be looked at first. Also: step up your PM maintenance and make sure you have the systems ph balance checked regularly as well as the air valve. Example: if you have a hotwater heater and the pressure control valve sticks and the fuel valve doesn't shut down, then what do you have? A Hydrogen Bomb, same thing here.

__________________
If you do nothing, so is the reward - R. Hulette
Register to Reply Score 1 for Off Topic
Guru

Join Date: Aug 2007
Location: Earth - I think.
Posts: 2143
Good Answers: 165
#12

Re: Water Pump "Explosion"

08/08/2013 10:04 AM

Closed outlet valve, pump cavitates, builds up enough heat & pressure. BOOM!

I have seen pump volute pieces that were shot 10 feet across a room and embedded in a concrete wall from a pump cavitating.

__________________
TANSTAAFL (If you don't know what that means, Google it - yourself)
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#13
In reply to #12

Re: Water Pump "Explosion"

08/08/2013 1:11 PM

Kilowatt-

You are right but not exactly. I will give it to you though! I had to investigate an incident as I described in another of the company's locations because no one could figure it out and the extensive damage done by the pump "exploding". Situation was a water circulation piping for a reactor cooling jacket. Safety was weeping onto an operator's feet so he put a plug (which he was unauthorized to do) in the discharge. About 2 weeks later Murphy's law came to visit. A mechanic came to work on the piping beyond the pump. Since an operator was not in the area, and he was impatient because he wanted to take a smoke, the mechanic isolated the pump by closing the inlet and outlet valves. the 10 hp motor kept on driving the pump, water heated up in the pump, water became steam, caused a BLEVE, and the pump exploded. All this because of personnel errors and the pressure generated by changing the mechanical energy to heat energy.

Depending upon the of the liquid this may be possible with other pumped materials.

This came to mind because of a recently issue of the "BEACON" published by The Am Inst. Of Chen Engs, August2013 http://www.aiche.org/ccps/resources/process-safety-beacon/201308/English

Please refer to it, I can't get my picture "mover" to work!

Thank you all for your contributions. This question was posted in order to see if there was anything we missed or if others might have different answers to the accident that might be investigated.

Thank you all!

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply Score 1 for Good Answer
Guru

Join Date: Mar 2012
Location: Out of your mind! Not in sight!
Posts: 4425
Good Answers: 107
#20
In reply to #13

Re: Water Pump "Explosion"

08/08/2013 11:55 PM

This is a weird thing of trying to find points that you might have missed. You did omit most of the information inclusiv what type of pump it was.

I believe you found out what happend and all of us would have if there was just enough information.

If it was worth the excercise so be it!

All the best!

__________________
Common Sense Dictates
Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#35
In reply to #20

Re: Water Pump "Explosion"

08/09/2013 11:36 AM

IdeaSmith-

My intention was to not confuse things with information, which would have been interesting to know, that was not needed for the solution of the problem. Yes, the problem had already been solved but I wanted to solicit other answers from some of the really good minds out there to make sure there weren't other possibilities..

After spending very little time finding the problem, but much time verifying that was the correct answer, our determination was that all that needed to be known was: 1) the pump was running and had been for several days; 2) Water was the liquid; 3) valves were closed. Conclusion: mechanical energy converted to heat that heated the water causing steam to be generated, the pressure caused the pump to explode.

Sometimes in our investigations/projects, we overload ourselves with information which hides the more obvious things from us.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#15
In reply to #12

Re: Water Pump "Explosion"

08/08/2013 4:48 PM

Kilowatt0

What I meant by not exactly but close enough was for you getting the answer nearly right. If the intake valve was not closed the pressure build up, beyond the normal output pressure of the pump, would travel back through the inlet piping. This would not hold true if a check valve or some other one-way device was located in the suction piping.

Refer to the article I cited. As you said "pump volute pieces that were shot 10 feet across a room and embedded in a concrete wall from a pump cavitating" is not a fun thing if you are standing in the way!

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
2
Guru
Hobbies - DIY Welding - New Member

Join Date: Apr 2008
Location: Bristol, Tennessee
Posts: 1176
Good Answers: 57
#14

Re: Water Pump "Explosion"

08/08/2013 3:42 PM

If you get water hammer in the system, the pump housing may be the weakest metal in the system, and will shatter.

__________________
mike k
Register to Reply Good Answer (Score 2)
Guru

Join Date: May 2009
Location: Wolfe Island, ON
Posts: 1358
Good Answers: 109
#16

Re: Water Pump "Explosion"

08/08/2013 10:30 PM

Believe it or not, I have seen the results of a piston pump that had been used on a golf course for irrigation "explode". I did not see the explosion but was called in to repair a problem. When I went to the pump house with the owner and saw the results I started laughing. He had a very old WWII piston pump from some frigate and had now used it for his irrigation system. The cast housing on the pump actually fatigued and split into several pieces. it was without a doubt finished. It was okay for me to laugh because he hired our firm to undergo a complete revamp and ground water study. In the long run he was able to expand his golf course with more holes and a better delivery system. But the pump did fall to pieces, not exactly an explosion but dramatic for the owner and a first for me.

__________________
If they want holy water, tell them to boil the hell out of it.
Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#17
In reply to #16

Re: Water Pump "Explosion"

08/08/2013 10:41 PM

Kevinm-

I believe it!

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Power-User

Join Date: Sep 2007
Location: Sheboygan, WI USA
Posts: 372
Good Answers: 13
#18

Re: Water Pump "Explosion"

08/08/2013 11:24 PM

Was this system down for repairs recently ?

Does the pump have a strainer upstream ?

If not, why not ?

Have you checked the strainer for holes bigger then there should be for the clearances in the pump ?

Was the pump itself replaced ?

Hinting at a foreign object (nut, bolt, washer, part of strainer) being in the pipe, either recent or long ago and just broke loose now due to higher flow, or other reason.

Was the pump runner old that it might have cavitated itself until it was structurally unsound ?

We haven't been told the horsepower of the driver or the head on the pump or a lot of other info. It doesn't sound like there was a coupling, i.e. direct shaft flange coupling in a large vertical pump ?

I've also known a steam fitter who forgot a rag in a pipe, which can plug a strainer.

__________________
"I believe we are masters of our lives - we hold all the cards and it is up to us to use them right." Vesna Vulova - survived 33,000ft fall
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#22
In reply to #18

Re: Water Pump "Explosion"

08/09/2013 12:42 AM

CoronaCameraMan

Repairs recently- No, pump always needed no more than regular PM

Strainer- several in system due to start-up foreign materials 5 years prior. All strainers were dual strainers with isolation valves to facilitate strainer cleaning without shutting the system down. Integrity of strainers checked when opened for weekly PM

Strainers checked as part of weekly PM.

Pump was 5 years old. Never any problems with it. Replaced after explosion. Motor also replaced in case of internal damage and need to get production back up.

No foreign objects as determined by strainers. Also no record of piping being opened since last 6 months of PM

No cavitation. flooded system. inlet under pos pressure conditions

As noted in #13, 10 Hp, head approx. 20ft, coupling to facilitate easy removal of motor or pump and coupling alignment was laser, one of the first applications of this. Horizontal shafting.

As noted above no foreign objects. Area was closely examined and all parts removed and saved. Pump was "reconstructed", similar to crashed airplanes, and no extra parts were present. We were very interested in this incident because this set-up was used in approx.. 100 set-ups in our plants.

Result of this incident was that all pump feed and discharge valves were fitted with lockable handles with lock-out devices and maintenance super's lock and production eng's lock both on. Valves were locked open with breakable hasp locks. 3 lbs. ball peen located nearby.

Good Luck, Old

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru
Engineering Fields - Civil Engineering - Member

Join Date: Mar 2011
Location: ''but, don't we get PAID to ask questions?...''
Posts: 1661
Good Answers: 17
#53
In reply to #22

Re: Water Pump "Explosion"

08/10/2013 7:06 PM

Sounds like you did start to do a sort of forensic investigation, so I have to ask if you were able to estimate where the exploded pump actually failed first ?...

__________________
''illigitimi non carborundum...''(i.e.: don't let the fatherless (self-deluding,sabotaging, long-term-memory-impaired, knee-jerking, cheap-shotting, mono-syllabic, self-annointed, shadow-lurking, back-biting, off-topic-inquisitors) grind you down...)
Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#54
In reply to #53

Re: Water Pump "Explosion"

08/10/2013 8:28 PM

Mr Guest-

We never came to a conclusive answer, but best theory was at the face, the thinnest part of the casing.

Thanks for asking!

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Power-User

Join Date: Sep 2007
Location: Sheboygan, WI USA
Posts: 372
Good Answers: 13
#19

Re: Water Pump "Explosion"

08/08/2013 11:27 PM

Was this system down for repairs recently ?

Does the pump have a strainer upstream ?

If not, why not ?

Have you checked the strainer for holes bigger then there should be for the clearances in the pump ?

Was the pump itself replaced ?

Hinting at a foreign object (nut, bolt, washer, part of strainer) being in the pipe, either recent or long ago and just broke loose now due to higher flow, or other reason.

Was the pump runner old that it might have cavitated itself until it was structurally unsound ?

We haven't been told the horsepower of the driver or the head on the pump or a lot of other info. It doesn't sound like there was a coupling, i.e. direct shaft flange coupling in a large vertical pump ?

I've also known a steam fitter who forgot a rag in a pipe, which can plug a strainer.

__________________
"I believe we are masters of our lives - we hold all the cards and it is up to us to use them right." Vesna Vulova - survived 33,000ft fall
Register to Reply
Participant

Join Date: Aug 2013
Posts: 1
#21

Re: Water Pump "Explosion"

08/09/2013 12:01 AM

Cavitation in the system can cause significant pressure surges and high heat conditions. If the situation becomes severe enough, the combination of high temperatures and sudden surges in pressure might cause a catastrophic pump failure.

Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#27
In reply to #21

Re: Water Pump "Explosion"

08/09/2013 10:09 AM

bcbaking1955-

Yes, cavitation can cause several significant problems. At the start of our investigation we were hoping that might be a cause for the explosion since it could be easily solve. Regretfully we had to go further.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru

Join Date: Jun 2009
Location: Ontario Canada
Posts: 930
Good Answers: 31
#24

Re: Water Pump "Explosion"

08/09/2013 8:40 AM

What exploded, the housing, the rotor, do you have any photos? What was the construction material? What were you pumping, just water or ??

__________________
The fine line between cuddling and holding one down to prevent escape must be learned
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#30
In reply to #24

Re: Water Pump "Explosion"

08/09/2013 10:24 AM

roy hammy-

Housing exploded. Don't have any pictures since I left their employ for bigger and better things. Steel. Water.

For photos refer to the Beacon site:

http://www.aiche.org/ccps/resources/process-safety-beacon/201308/English

These pictures are representative of our explosion.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
3
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 14331
Good Answers: 161
#25

Re: Water Pump "Explosion"

08/09/2013 9:03 AM

I was going to say the mechanical equivalent of heat happened to the pump: operating with a volute with no way in or out would result in a boiling liquid at the pressure failure point of the casing. But by the time I saw this article, there were already 20 answers, and the OP basically answered his own question.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply Good Answer (Score 3)
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#28
In reply to #25

Re: Water Pump "Explosion"

08/09/2013 10:16 AM

James Stewart-

You are absolutely correct! Your answer was a perfect example of "Looking at the tree and not being distracted by the forest" (analogy)

I gave the answer because someone gave an answer that was extremely close to the correct answer. I thought that to go further might create confusion by having some answers create "tangential distractions" from the subject.

I have given you a GA for such a good and direct answer. I hope others feel the same way and do likewise.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Power-User
United States - Member - NE, USA Hobbies - Target Shooting - New Member Engineering Fields - Aerospace Engineering - Engineering Fields - Electromechanical Engineering - New Member

Join Date: Jul 2007
Location: USA
Posts: 199
Good Answers: 6
#26

Re: Water Pump "Explosion"

08/09/2013 9:43 AM

Too much pressure.

Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#29
In reply to #26

Re: Water Pump "Explosion"

08/09/2013 10:18 AM

JCase-

Yes, too much pressure, with an infrequent cause.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Participant

Join Date: Aug 2013
Posts: 2
#31

Re: Water Pump "Explosion"

08/09/2013 10:26 AM

Severe cavitation if this is a centrifugal pump?

Register to Reply
2
Guru

Join Date: Jun 2013
Location: Central Canada
Posts: 677
Good Answers: 28
#32

Re: Water Pump "Explosion"

08/09/2013 10:43 AM

I can only offer a suggestion, based on first hand experience. I ran a 9hp gas pump to a water system and one day
I was investigating a low / no pressure situation. When I approached the pump house I could hear that the engine was running under minimal load, and on opening the doors could smell the paint off the pump assembly. I was smart enough to not touch the housing, and before shutting the engine down I closed the upstream valve to prevent backflow. I was going to wait for the thing to cool down, and began searching for the reason the pump lost prime. It was not positive inlet pressure, so a tiny hole would cause a loss of prime. After a short time I was fairly certain I had corrected the input leak, and wanted to go back to service ASAP. I realized that the housing was still way too hot for my liking and decided to crack the upstream valve to allow a little cool water to backflow and help cool things off. Luckily for me the outlet tubing was plastic, because it was already soft from the heat thrown off the housing, and when the first water hit the housing it flashed to steam and blew the tubing like a balloon. I was suddenly in a room full of vapor but I survived to tell the tale. Did your pump show signs of heat prior to the event, if so I might suggest a temporary loss of prime, buildup of heat, and then a tiny ingestion of water to cause the steam explosion.

__________________
Smart as a post and twice as fast.
Register to Reply Good Answer (Score 2)
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#33
In reply to #32

Re: Water Pump "Explosion"

08/09/2013 11:18 AM

LongintheTooth-

Your situation is very representative of what loss of prime can do to a pump. You are fortunate that you were not injured.

The pump I mentioned showed no signs of holes, no matter how small in the inlet or the inlet piping. It was located 20 ft below the surge tank that was feeling it. Surge tank had an alarm on it to indicate when it's level was less than 1/2 of its 200 gal capacity. No one could tell me if pump paint showed signs of heating/blistering prior to explosion. I was called in 2 days after the incident when local personnel couldn't find a reason.

Although there were many possibilities, we were able to reduce them down to the inlet and outlet valves being closed. Wisely the local plant engineer isolated the area and put another similar system in service. I was told by him that the valve positions had not changed since the explosion and both were closed when I arrived. This was verified by pictures taken immediately after the incident. Full investigation was done and that is the conclusion we came to.

As confirmation, the local engineers had an intern and a mechanic reproduce the incident with a smaller pump and a 1/2 hp motor. After a while it too had the same results (within a container to prevent injuries to observers).

Glad to see you survived your incident without any damage to you. Murphy's Law is always over your shoulder, whether because of you or someone else!

After seeing the Beacon by the AICHE, I was surprised that this type of condition was so frequent.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru

Join Date: Jun 2009
Location: Ontario Canada
Posts: 930
Good Answers: 31
#34
In reply to #33

Re: Water Pump "Explosion"

08/09/2013 11:31 AM

Based on some internet searching I found quickly that centrifugal pump under restricted outlet conditions up to 450 PSI can be produced with sufficient HP, Not that this is gospel but much higher than I thought was possible. When you take 450 PSI and multiply by surface area in Sq.In. there is a lot of force on the internal parts. Keep on learning..

__________________
The fine line between cuddling and holding one down to prevent escape must be learned
Register to Reply Score 1 for Good Answer
Guru

Join Date: Jun 2013
Location: Central Canada
Posts: 677
Good Answers: 28
#36
In reply to #33

Re: Water Pump "Explosion"

08/09/2013 11:55 AM

Thanks , Salty - I could have arrived a few minutes later and had the thing do its business in front of me without my help - but as you say fortunate for me, and my work did save the hardware as well. Yes I agree your assessment was probably right, it would only take a tiny ingress of water thru either valve to cause the steam explosion. I suspect that the valves may have been heated to the point where they began to leak just enough to release a trickle of water into the hot chamber (unless they were far enough removed to be out of the heat zone the steam could have travelled a fair distance to the valve). Same result, only louder, lol. Interesting I did not read of any loss-of-flow alarms in the system, they would have reported the valves closed before destructive effects. I suppose if the assembly was filled with water that had nowhere to go then it would easily have had enough to build any amount of steam pressure, and override any relief by sheer volume.

__________________
Smart as a post and twice as fast.
Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 14331
Good Answers: 161
#50
In reply to #33

Re: Water Pump "Explosion"

08/10/2013 9:13 AM

This whole scenario, and others like it make a strong case for (1) having a good lock-out tag-out problem that is religiously followed, and (2) anytime a major pump is utilized with negative NPSH, perhaps a pony pump should be installed upstream as a priming pump, or change the system design to one where the actual pump is designed for low head, or suction lift situation. Another useful consideration is automation with a PLC, and interlocks. Even with that, valves have been known to stick closed.

__________________
If it ain't broke, don't fix it. Just build a better one.
Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#51
In reply to #50

Re: Water Pump "Explosion"

08/10/2013 11:17 AM

James Stewart-

How right you are, especially the valves sticking! Not just at work but also at home.

Recent war story, slightly embarrassing because of my profession but worth repeating:

I was installing another hose bib on the deck to make it convenient for the wife to water her flowers. Had everything together but wife and daughter wouldn't let me shut down city water to house for the final connection until after 11pm because of their water needs i.e. shampooing, washing clothes, etc. I closed the gate valve in the house, from the curb valve, and did the installation. It looked very "pretty" if I do say myself! Went to open the gate valve and the stem/handle kept on turning with no water flowing. Tried closing it again and opening it, still no water.

By now it was 11:45pm. Called the water company to shut the curb valve. Had to exaggerate some to get them to send someone out at midnight. 1/2 hour later the door bell rings, it's my savior from the water co. Went to the basement and explained the problem. He stated "we don't work on anything in the house, you have to call a plumber". Told him can't get one at that hour, even my friend, but could I do it myself? "Sure" and he shut the curb valve. He kindly stayed here while I spent 15 minutes replacing the valve. He opened the curb and NO LEAKS!

Took a look at the old valve and the threads on the stem had oxidized enough that they were almost missing, at least enough to not pull the gate up. Even with PM of operating the valve I still wouldn't have been able to detect the disintegration of the stem until it failed. Alternative is to have water company shut curb valve, take the valve apart, check it and have curb valve opened periodically. Not something water co likes to do.

Fortunately the guy and I had similar interests so he stayed for 2 hours and we exchanged old war stories!

Axiom: Murphy's law can intervene on the best plans no matter where it is!

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Power-User

Join Date: Jun 2010
Location: Amsterdam, Netherlands
Posts: 342
Good Answers: 32
#37

Re: Water Pump "Explosion"

08/09/2013 12:44 PM

It was way below freezing that morning. or . The technician was chilling a beer with a CO2 extinguisher.

__________________
Humans are just smart enough to fool themselves.
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#42
In reply to #37

Re: Water Pump "Explosion"

08/09/2013 2:23 PM

So that's why CO2 extinguishers are mysteriously empty and not dry chems when the grave yard shifts leaves! And here I thought they were only used to cool motors that were running hot and personnel wanted to go home on time! So that's why breakers tripped the first time motors they were used in the morning! Imagine that!

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru
Engineering Fields - Mechanical Engineering - Ever Changing United States - Member - From the Redwoods to the Valleys Engineering Fields - Control Engineering - Building blocks or writing code - to keep you comfortable

Join Date: Apr 2008
Location: 38th Parallel
Posts: 751
Good Answers: 19
#38

Re: Water Pump "Explosion"

08/09/2013 1:16 PM

Poor Maintenance and safety inspection procedures!

__________________
To be or not to be........ok that's a trick question.
Register to Reply
Guru

Join Date: Jun 2013
Location: Central Canada
Posts: 677
Good Answers: 28
#39
In reply to #38

Re: Water Pump "Explosion"

08/09/2013 1:31 PM

- - Might cover the WHY but not the HOW lol

__________________
Smart as a post and twice as fast.
Register to Reply Score 1 for Good Answer
Guru
Engineering Fields - Mechanical Engineering - Ever Changing United States - Member - From the Redwoods to the Valleys Engineering Fields - Control Engineering - Building blocks or writing code - to keep you comfortable

Join Date: Apr 2008
Location: 38th Parallel
Posts: 751
Good Answers: 19
#40
In reply to #39

Re: Water Pump "Explosion"

08/09/2013 1:45 PM

Could be, but if good maintance practices are enforced......valves are checked, reliefs are checked, systems are blown down, strainers are cleaned to prevent blockages and sticking devices....operator error is the only thing left....except for the act of god that just causes the pressures to build and explosion to occur.

__________________
To be or not to be........ok that's a trick question.
Register to Reply Score 1 for Off Topic
Guru

Join Date: Jun 2013
Location: Central Canada
Posts: 677
Good Answers: 28
#41
In reply to #40

Re: Water Pump "Explosion"

08/09/2013 2:08 PM

Still all of that speaks only to WHY not HOW. OP specifically asked for a mechanism whereby the failure could occur. His investigation was to find the reason HOW and the finger pointing WHY came later.

__________________
Smart as a post and twice as fast.
Register to Reply Score 1 for Good Answer
Guru
Engineering Fields - Mechanical Engineering - Ever Changing United States - Member - From the Redwoods to the Valleys Engineering Fields - Control Engineering - Building blocks or writing code - to keep you comfortable

Join Date: Apr 2008
Location: 38th Parallel
Posts: 751
Good Answers: 19
#43
In reply to #41

Re: Water Pump "Explosion"

08/09/2013 2:23 PM

yep, exactly, the how was the latter. Operator error sombody closed the valves causing a blockage in the pumps outlet producing steam by friction and thus blowing up the pump, was the given explanation. If not operator error, then poor maintenance of the system caused the valves to stick and the relief not to blow, thus resulting in how the pressure built to blow up the pump.

I have always found that the why is the quickest result to the how. Or the the whats changed gets yo to the how, then back to the why....but its the why that always tells the truth of how it happened.

Is it the chicken or the egg?

__________________
To be or not to be........ok that's a trick question.
Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#46
In reply to #43

Re: Water Pump "Explosion"

08/09/2013 2:59 PM

Original post was addressed to HOW this could happen, not WHY it happened. There are too many reasons why this could have happened for this forum. As you state there are several obvious ways that this condition could have been derived from.

In order to not get bogged down in this aspect and to obtain others view points as to what happened and how it happened I made no reference to why or give information as to things that were irreverent to solving this technical question. Because I am intimately familiar with the human phycology of manufacturing and the personnel involved at all levels, I limited the question to what happened and how it happened.

If I led people astray with this exclusion of information, I apologize.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
2
Guru

Join Date: Jun 2013
Location: Central Canada
Posts: 677
Good Answers: 28
#47
In reply to #46

Re: Water Pump "Explosion"

08/09/2013 3:04 PM

I think OP was well stated. Just enough information to focus on the desired answer and not a red herring.

__________________
Smart as a post and twice as fast.
Register to Reply Good Answer (Score 2)
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#49
In reply to #47

Re: Water Pump "Explosion"

08/09/2013 3:07 PM

LongintheTooth-

Thank you for your clarification for the contributors.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#44
In reply to #38

Re: Water Pump "Explosion"

08/09/2013 2:43 PM

Stedou73ish-

I wish I could agree with you but any pump that has as good a record as this one is a good one in most eyes of maintenance personnel.

No repairs in 5 years.

Weekly PM done diligently with no problems noted. PM sheets verified by production engineer of area or responsibility. Remember the maintenance vs. production blaming the other for anything that is out of the ordinary? This was not the case.

No opening of piping for 6 months

Parallel screens with isolation valves facilitated opening and inspection of screens while cleaning them.

Regretfully safety valve was not in the forefront of the operator.

Safety Dept put their holy water on it. In view of PSM they reviewed all P&ID's during Haz Op meetings with other various disciplines and all came to agreement. Safety also did periodic intense reviews of operating equipment while in operation with engineering, production eng and operating representative.

It would have been easier to blame poor maintenance or safety but I wish every operation was scrutinized as closely as this one.

This is not to exclude poor maintenance and safety from all cases. It is probably the most frequent source of problems along with operator error. These are a very viable problem in many installations, but not this one.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
2
Guru
Engineering Fields - Mechanical Engineering - Ever Changing United States - Member - From the Redwoods to the Valleys Engineering Fields - Control Engineering - Building blocks or writing code - to keep you comfortable

Join Date: Apr 2008
Location: 38th Parallel
Posts: 751
Good Answers: 19
#45
In reply to #44

Re: Water Pump "Explosion"

08/09/2013 2:50 PM

Its good to know that your team is on top of it and doing their job.

Unfortunately, I have had the "opportunity" to enter into locations that do not have the same type of procedures that you have in place. I wish all locations had the respect for the equipment, and maintenance procedures that you and your team have.

Its good to know there are some out there that still care and are doing it right.

Thanks Old Salt.

__________________
To be or not to be........ok that's a trick question.
Register to Reply Good Answer (Score 2)
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#48
In reply to #45

Re: Water Pump "Explosion"

08/09/2013 3:05 PM

Yes, striving to make things better and adhering to these higher levels are our bread and butter. And sometimes our health, our lives, the future of our families, and our coworkers health and lives.

Thank you for your fine contribution.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply Score 1 for Good Answer
Power-User

Join Date: Aug 2013
Location: OHIO, tri-State design and installation, and travel nationally and consults also are international
Posts: 275
#55
In reply to #48

Re: Water Pump "Explosion"

08/10/2013 10:28 PM

seen cavitation(s) allow a tornado like (conical shaped) borehole through steel and especially iron bodies of cast iron casings...

(too restricted on INTAKE) etc...

metal fatigue re vibration,

then would be a quicker failure due to any closed valves, or 3.14159265358 x 10^23rd other reasons contributing

__________________
Simply choose your utility supplier contracting WITHOUT BROKERS and opt-out of community aggregations for free choices.
Register to Reply
Guru
Safety - Hazmat - New Member Engineering Fields - Retired Engineers / Mentors - New Member Engineering Fields - Piping Design Engineering - New Member Hobbies - DIY Welding - New Member Fans of Old Computers - PDP 11 - New Member

Join Date: Feb 2007
Location: Stronger Than The Storm
Posts: 2391
Good Answers: 202
#56
In reply to #55

Re: Water Pump "Explosion"

08/10/2013 11:01 PM

JP76-

You never know beforehand when these things will happen.

While working my way through college, I saw the proverbial Oxygen cylinder with a broken off valve go through a concrete block wall. That experience has a high pucker power. Also had to change my briefs.

Good Luck, Old Salt

__________________
Any day on the green side of the grass is a GREAT DAY!, --- me +++++++++. I believe creativity is an inherent part of everyone. --- Kermit T. Frog
Register to Reply
Guru
Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2008
Location: CHENNAI, TAMIL NADU, INDIA.
Posts: 1854
Good Answers: 64
#52

Re: Water Pump "Explosion"

08/10/2013 11:21 AM

Dear Mr.old salt,

Is it a POSITIVE DISPLACEMENT PUMP.? Whether somebody has closed the Delivery Valve.? If so it will explode.

DHAYANANDHAN.S

Register to Reply Score 1 for Good Answer
Register to Reply 58 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

bcbaking1955 (1); CoronaCameraMan (2); dhayanandhan (1); dvmdsc (1); IdeaSmith (3); James Stewart (2); JCase (1); jesw55 (1); JP76 (1); kendall (1); kevinm (1); Kilowatt0 (1); LongintheTooth (6); Michael Smith (1); mike k (1); MR. Guest (1); old salt (21); PWSlack (2); RandallAvery (1); roy hammy (2); Stedou73ish (4); tcmtech (1); Tornado (2)

Previous in Forum: Need Info for a Integral Hydraulik Unit   Next in Forum: Ergonomics

Advertisement