Fire Pump Testing

[BoogyMouse]

I currently fill the role of site supervisor of plant protection for large site in Indiana. One of my responsibilites is testing the fire suppression systems on site. There are 2 electric fire pumps on site and a large diesel pump with a 200,000 gallon tank. When testing these pumps I run into a major issue as I keep blowing underground fire mains. These breaks cost significant damages. Is there anyone who knows the proper way to test these pumps without blowing fire lines? I've heard two opposite theories. The first is to open a fire hydrant before testing to give the water a place to exit the system. However, I've been told it's the flow and not the pressure that is breaking the lines. It seems opening a hydrant would only make it worse. We are talking about extremely old pipes that are made of clay... Is it possible this inspecion regulation is impossible to accomplish with this system?

 

[Artisi]

Sounds to me like you don't really have a fire protection system at all - if you're breaking pipes under test, as fire protection system it's useless.

Guess you source of consultation is absolutely correct in saying it's the flow that's breaking the pipes - it stands to reason - if there is no flow, there is no pressure being applied to the pipes to cause the pipe failure.

If you follow the above line of thinking - what is causing the failure is you starting the pumps - my advice is don't ever run the pumps - never ever - that way you will not have a pipe failure.

I'm sure glad I'm not underwritting your fire insurance .


Naresuan University
Phitsanulok
Thailand

 

[BoogyMouse]

So what you're saying is that I'm not personally doing anything wrong to cause the breaks? Basically what I do is open a test valve which drops the pressure enough to start the pump and then let it run anywhere from 7 minutes to 30 minutes depending on which pump it is. Then I take reading off various gauges (motor rpm, oil pressure, suction pressure, discharge pressure).

Boogymouse
Plant Protection
Site Supervisor

 

[Artisi]

Normally fire pump/s start startup when there is a drop in pressure from a hydrant being opened or a sprinkler system starting up.
what you are doing is correct, open a valve to drop the pressure to start the pump/s. I would run them at a flow rate somewhere near the design flow and check flow rate and pressure, motor current and general operation of the diesel unit.
Clay pipes are not appropriate for a fire pump system - as you are now proving with your testing.


Naresuan University
Phitsanulok
Thailand

 

[BoogyMouse]

We're talking about a lot of line and a lot of buidlings. I believe they only put in the pumps because of regulations after the lines had already been placed. They are in the process of closing a lot of the buidlings and i can't see them spending the money to replace the lines. Also, as a lowly contractor, my opinion doesn't really mean much. Well, thanks for the help. I'll try my best not to blow the place up.

Boogymouse
Plant Protection
Site Supervisor

 

[abeltio]

the problem with blowing the whistle is that more likely than not... the whistle blower will be blamed.

in your case: testing the pumps means breaking the system... therefore, the system does not pass the required test and is not fit for purpose.

as artisi mentioned... you do not have a fire protection system... i would say that what you have is: "a system to perform destructive testing of piping".

if you are responsible for the tests, meaning that your signature certificates that the system is good to go... you are setting yourself up for a big criminal lawsuit against yourself and your company in case of a fire where the system breaks when put in service.

instead of a test of the pumps you should organize with the principal (or owner) a "fire protection drill". i.e. designate an area as the hazard zone, and simulate the real situation starting from the normal stand-by condition.

if you keep approving the tests even when the pipes break... you are just adding material to your "Titanic Files".

if you are threatened with termination because of the cost of replacing the lines... so be it... move on... and just casually let the local fire marshall know about the situation.

not fun.
cheers.



saludos.
a.

 

[BoogyMouse]

Well, my position isn't that complicated. I'm only responsible for testing the system and then reporting my findings to the client. Once my findings are reported and filed in writing my responsiblity ends as I've done my part. It is the client's responsiblity to make the corrections so that the tests during the following week do not turn up the same results.

Boogymouse
Plant Protection
Site Supervisor

 

[Artisi]

My report would include the repeated (if this is the case) pipeline failures when the pumps are put into service to test - as you have said that you have to report on the "system" which includes pipeline.

If your responsibilty is only for the pumps all the better for you, but make it very clear in your report that you you're not responsible for the testing and the integrity of the pipeline, therefore the fire system as a whole.

Naresuan University
Phitsanulok
Thailand

 

[BoogyMouse]

Did a little investigative digging and have found that many times the fire pumps are coming on due to jockey pump failure. Frequent changes from 74 PSI to 120 PSI or 80 PSI to 140 PSI could cause some of the pipe line problems, could it not? That in itself seems like an incredible strain on the system. Especially when it's happening so frequently. I also discovered that the information I'd been given about the material of the pipe lines was incorrect. They are not clay pipes. The pipe lines themselves are placed 7 feet below the surface and therefore ENCASED in clay.

Boogymouse
Plant Protection
Site Supervisor

 

[Artisi]

This is a fire pump "system" which includes the pipeline - and if anything is failing there is something very wrong.

You need to establish what the design pressure is for the system and what the cut-out pressure for the jacking pump is set at - what material is the pipeline.
The jacking pump should be set to shut off at a pressure only marginally higher than the fire operating pressure.

If the the pipe line is failing on test - something is very wrong with the pipeline design. What is failing - the pipe or the pipe connections?

You need to do a thorough engineering investigation into the whole system - it might be in the interests of the ownwer to hire in an enginner who can evaluate the overall system and make some recommendations, as at the moment you don't appear to have any fire protection for the plant.

Naresuan University
Phitsanulok
Thailand

 

[BoogyMouse]

I will look into finding the answers to these questions. However, usually when I ask questions the response I usually get is "I don't know."

In regard to what is failing in the pipes... I can say it is a little bit of everything. Recently we have replaced 2 or 3 curb valves (one belonging to the city), 1 PIV (changed into a curb valve), a riser in a stairwell blew a hole in the pipe itself, and the rest of the breaks (about 4) have all been holes blown in the underground pipe itself. One of the breaks was under the garage to the security building. There were at least 4 other breaks this past year before the company I work for took over the contract. I belive all of those breaks were in the pipes themselves. And all of these issues started when testing of the fire pumps began due to a very embarassing audit by the insurance holder.

I believe the material the pipes are made out of is steel.

The break under the garage and the break in the riser were in separate buildings on opposite sides of a main city street. Maintenance was tensting a new jockey pump and put 165 PSI through the line.

Another response I get from a member of client management is "They're old pipes. You have to be more careful when testing the pumps." And he insists opening a fire hydrant while testing will solve the problem as a means of giving the water an exit point.

Boogymouse
Plant Protection
Site Supervisor

 

[Artisi]

Next time you test, open 1 or 2 hydrants which is necessary anyway to establish if the pumps are capable of delivering the flow and pressure needed to operate the fire system.
If there is failure of the pipeline or valves it just confirms that the pipeline is insufficient for the job, which is not your problem.



Naresuan University
Phitsanulok
Thailand

 

[BoogyMouse]

As I figured, no one in maintenance knows anything about the design pressure. By "cut out" pressure I assume you mean when the jockypump kicks off. That is usuall 120 or 125psi. I opend a hydrant during the last test and the ground actually rumbled and vibrated, but none of the lines broke...

None of this really matter anymore since I will be removed as Site Supervisor at the end of the month... This will soon be someone elses problem.

Boogymouse
Plant Protection
Site Supervisor

 

[Artisi]

I think your lucky getting away from a problem installation like this.

As I don't know what size pump units you have, I can't really comment on whether 1 hydrant is sufficient to duplicate a meaningful test.

Naresuan University
Phitsanulok
Thailand

 

[BoogyMouse]

I just wanted to wrap this up with the solution we came up with for the problem. First of all since 2 of the main pumps are connected to the same system we decided that while testing one, we would shut the other down. The one we test at the time should be enough if we have a fire during that time and we always have the option of turning the second back on in case of an emergency. The problem were were having is that while testing one pump, the other kept kicking on as well. Since we were not focusing on the second pump we kept having an officer turn it off every time it'd kick on. It was the constant on and off of the second pump that was weaking the lines and forcing them to break. It was like taking a hammer and pounding the system over and over and over. No system is designed to withstand a main pump turning on and off repetitively. Opening a hydrant also seemed to work as it gives us an accurate representation for a fire or a line break to see if the system can withstand the pressure. Using the small test valve at the pump was giving us an inaccurate reading as that valve was attatched to the same line as the gauge we take the pressure reading from.

So basic procedure. Before testing one pump, we shut the other down. We open a fire hydrant to drop the pressure and test the pump. If they hydrant isn't enough to drop the pressure far enough, we turn the test valve briefly, just enough to turn the pump on then we close the test valve and take our readings. We leave the hydrant open the full 30 minutes and simply let the pump do its thing. Then we close the hydrant and shut off the pump then refill the suction tank. Since we started this procedure we have not had any lines breaking.

Boogymouse
Plant Protection
Site Supervisor

 

[Artisi]

Good to hear your have sorted out the problem.

Naresuan University
Phitsanulok
Thailand