Thread: Can you stop an argument ????
07-19-2000, 12:54 PM #1Fyrball105Firehouse.com Guest
Can you stop an argument ????
I have found a very hot subject at my department,And I need some outside people to think over and tell me what works for you guys. It involves three words, you hear these three words and the war is on. "prime the pump."I believe the primer is for drafting water, and that is the only time I have had to use it. In the winter we drain the pumps to try to keep them from freezing, so some guys say that they can't get water from a drained pump till it is primed? I can I have, just open tank suction, your lines run up presure, that simple, the tank to pump should be gravity feed if not seems the pump creates enough suction inside it's self to pull from tank, If you ever been on end of hose waiting on water, let me tell you the sound of a primer screaming, will make the B/P shoot sky high> I have showed how easy I have been able to get water from drained pump, and they still think the primer is answer, It's becoming a real problem, like a qiuck fix, all else fails pull the primer.I do know that maybe if parked on an incline over maybe 45 degrees or something the primer maybe needed. I'm not saying it's just for drafting,just that only time I have had to use it.you guys have any ideas, info, or input out there?
[This message has been edited by Fyrball105 (edited July 19, 2000).]
07-19-2000, 01:13 PM #2Hosekey21Firehouse.com Guest
Both of our Pumpers are the same way, gravity fed. We only need to use the primer for drafting. I understand your frustration as I was first taught that you had to prime the pump every time. I am wondering if there is a different pump design (older) that requires priming every time.
As a side note: I was also taught that you have to have the DP in high for pumping. I disagree, only the highest gear, DP has no bearing when in pump mode.
Just one man's view from the flames.
07-19-2000, 01:47 PM #3cacfpdFirehouse.com Guest
Priming the pump is most often accomplished by simply opening the tank valve as you have noted. Sometimes however an air pocket developes in the pump (normally when drained) which will require operating the primer for a short time. As far as using the primer for drafting, a good operator can often achieve prime by allowing tank water to backflow into the suction hose.
You can always count on a few "experts" to pull the primer knob severaal times before they figure out that they dont have the valve open or have something else wrong.
You noted how the B/P goes up when you are waiting for water at the hose. Try it when you had been spraying water which all of a sudden stopped and you hear the primer screaming.
07-19-2000, 02:17 PM #4Les.HFirehouse.com Guest
As stated, the pump should prime its self as the water tank is higher than the pump inlet valve. Head pressure will force the air out of the pump and so water can then be passed through the hose.
Sometimes an air lock can occur and then the primer can be brought into play if its a manual type or it will operate itself if automatic at 2000 revs. As we know, pumps will not pump air, so if there is a lot of it stuck in the main chamber then it has to be ejected one way or the other.
Our new pumps that are coming on line will not lift properly from open water until the drain valve is operated - eject the water from the casing - close valve and operate pump. The vacum is then created and water lifted from the open supply. Confusing ain't it.
Have you also noted that every pump has a character all of its own. The operater tends to know his pump and its associated problems and faults. All part of knowing your equipment and treating with a bit of TLC.
Kindest regards & keep safe,
07-19-2000, 05:13 PM #5M GFirehouse.com Guest
This is a good topic, being that I am enrolled in pump class as we speak. I have had expierences operating pumps, now I am formalizing that and taking the class. I am sure you understand that a fire pump (centrifugul) does not draw a vacuum until the impeller(s) are flooded. The impeller(s) must be flooded with water for the pump to draw suction. The primer simply expells air from the pump and lowers the pressure inside which draws vacuum. That said, if your tank to pump line(s) do not allow the water to flood the impeller(s) then you might not get a prime and get pressure. For instance, our 1964 Ford/Hahn pumper has the tank to pump line coming up from below in the suction inlet, so there is sometimes a need to prime from tankwater. Priming sounds bad...I agree, but it can save the crews from air in the lines. The other thing about priming is that you might get some results from tankwater by cracking a discharge while waiting for a prime. This practice doesnt usually work for drafting however. I like to see companies that have seperate primers for all the intakes, that shows a little bit of thought.
Ok so I have a question, how is it possible to get the tankwater to backflow into a suction hose with the pump engaged???
This information is based on what we are being taught in class and what i have learned on my own, if any of it is wrong let me know!
The information presented herin is simply my opinion and does not represent the opinion or view of my employer(s) or any department/agency to which I belong.
07-19-2000, 06:00 PM #6tc1chiefFirehouse.com Guest
Les. H hit the nail on the head. the PUMP OPERATOR not the PRIMER PUSHER knows what to and how to operate his/her engine and pump. If a person thinks they are a PUMP OPERATOR have a pump drill, drain the pump, and have them draft water using the steamer face not the 2 1/2, using the booster tank.
CAUTION: DO NOT LET THE PERSON THROTTLE UP THE DRY PUMP LIKE MOST WANT TO DO, UNLESS YOU LIKE INSTALLING WEAR RINGS IN THE PUMP.
Old pump operators never die, the just keep on pumping...
07-19-2000, 10:07 PM #7CaptCraigFirehouse.com Guest
Going back to part of your question. Why do you drain your pumps in the winter. Being in Tenneesse it shouldn't get any colder there than where I'm from in Louisville, KY. We don't drain ours, and never had a problem. Draining the pump and not exercising it can lead to seal failure and premature failure of your primer system.(Some yahoo who keeps pulling and pulling, saying I'm getting oil but no water!)
On back filling the suction hose remember: Gravity works! It helps to have a good tight pump to pull it's own prime without assistance from the primer system.
There's no better idea than to have an effective maintenance system with knowledgable and experienced mechanics. Proper pump testing and the like.
07-20-2000, 12:38 AM #8DDFirehouse.com Guest
Read and understand the pump operations manual for each pump that you have. Operate the pump according to the manufacturer's directions. Use those directions to settle the argument. The pump builders know more about their pumps than anyone.
[This message has been edited by DD (edited July 20, 2000).]
07-20-2000, 10:44 AM #9Fyrball105Firehouse.com Guest
Capt.Craig>> I'm in the foothills of mountains here, and we have had trouble with pump freeze, not every winter, but it has happened. and just to say the pump is not always drained, just when the weather is going to dip down below freezing. And to answer a question that seems to keep coming up> I'm talking about new trucks here, new pumper is a 98, our other pumper is 84, so they are not the type that needs primed to pump.
07-20-2000, 11:42 AM #10D. AndersonFirehouse.com Guest
I just made driver and our mechanic gave the new drivers a class and taught us that the easiest way to prime a pump is to open a gate and drain on an outlet with no hose attached momentarily and let the tank water gravity feed into the pump. It works faster and easier than to open the gate where you're laying the line off of because you don't have to push the air all the way out the hose. Some of our older pumpers leak from the pump and you have to prime them this way often.
I would like to add that we're about as cold as you can get in the winter and we don't drain our pumps, just circulate them.
07-20-2000, 12:03 PM #11eCappyFirehouse.com Guest
My two cents:
The old 500 GPM fire engines from the 40s and 50s (that I broke in on) had 300 or 450 gallon water tanks with 1 inch or 1 1/2 inch "tank to pump" piping.
Now most 1500 or 2000 GPM fire engines have 750 or 1000 gallon water tanks with at least 2 1/2 inch "tank to pump" piping. Some, like my 1996 Darley have 3 inch.
It's my belief that priming is no longer needed because of the larger volume of water flowing from the larger tanks through larger piping and into the pump.
07-20-2000, 01:56 PM #12Fyrball105Firehouse.com Guest
ok, the draining of the pump that keeps coming up is , when the trucks are just sitting in station, waiting on calls. we have sometimes very long hauls that we have to do, that would give water time to freeze. I'm not talking about draining on a fire scene. just after fire when truck is just sitting in station.and my question on priming wasn't pointed toward drafting, just on the arrival on firescene, after lines are layed, and your engineer is getting water, I'm just aguring with other guys here, they say they have to prime pump to get water, ok but no intake is open no where for water to come from, so all they are doing is burning primer till they open tank to pump lever.
07-25-2000, 10:11 PM #13Truck#109Firehouse.com Guest
Why run the primer when there is no water to prime with?
Being from southern Ont., it's S.O.P. for us to drain our pumps (especially in the winter months), so we are always working with a "dry" pump. For myself, all I ever do is bump up the r.p.m a little, pull the tank to pump valve and 99 times out of 100 it primes itself. Once and awhile it will get an air lock and need to be primed. But, that's our truck and not all tucks/pumps are the same.
Just my thoughts on the subject.
07-25-2000, 11:56 PM #14ProfVolFirehouse.com Guest
Was the question, do you need to prime or not? We make it a habit to pull the prime even with the tank to pump valve open. It does not hurt anything and it takes no longer to charge a line. This way, the pump operator does not have to worry if there is an air bubble or something. I agree that 99% of the time this is not needed but it will not hurt the priming pump. This way you know it will work if needed.
07-26-2000, 08:41 AM #15Bob SnyderFirehouse.com Guest
I've never really understood why this is such a hotly contested issue. It's really simple, the way I see it:
If I need a prime and have one, I don't prime.
If I need a prime and don't have one, I prime.
As a pump operator, shouldn't your actions be determined by conditions & needs, not by some arbitrary rule? Whether I'm on the nozzle or the pump panel, I really don't care HOW the necessary flow of water gets to the nozzle when it's needed...I just care THAT the necessary flow of water gets to the nozzle when needed and, of course, that it's properly maintained as long as needed.
I'm not too proud to prime from the tank, if I need to. I'm not going to waste time & oil priming if I don't need to. What's the big deal?
07-28-2000, 03:31 AM #16RetFireCaptFirehouse.com Guest
Many replies have hit the nail on the head, when you need to expell the air you may need to prime the pump. However, I see why instructors might be teaching personnel to use the primers all of the time in conjunction with opening the tank to pump valve. Some people are not very swift when it comes to mechanics. If they aren't shown to prime a dry pump then when the time comes to get water and just opening the tank to pump valve doesn't work, they will panic and it will be even longer before you get water. Their out will be, I was never taught how to do it. This doesn't excuse them for not being proficient in their job but in my 37 years in the fire service I can say I have heard that line numerous times.
The only thing that is happening is you are using primer oil but the time it takes to charge the line should not be affected. Being a proficient operator is the real answer to the problem!
08-24-2000, 02:30 PM #17RDWFIREFirehouse.com Guest
Bob Snyder hit it on the head. Each pump is different. Age, wear and tear, tank-to-pump piping, all have an effect on how rapidly your pump will self-prime. There is a lot of "that's the way we've always done it" in firefighting in general, and especially operating the pump.
Watch your gauges. If you need to prime DO IT.
Just my thoughts
08-24-2000, 09:50 PM #18FINTLYFirehouse.com Guest
As a E.V.T all I want to share with you it is a good habit to run the primer if even for only a couple of seconds. Not a month goes by when I dont find myself either rebuilding or replacing a primer unit on a couple of apperatus and the story is always the same from the poor chief that has to sign the bill "how can that be we never use the thing we almost always run off the tank"
My answer to them that is bingo thats the reason" the vanes in the primer need to be lubricated on a regular basis espesially using todays new enviromently safe priming agents.
So in cl0sing pull it your not going to hurt anything but you will if you don't
08-25-2000, 07:57 AM #19Jay SonnenfeldFirehouse.com Guest
I agree with the last reply. We are a small Fire Dept that runs approximately 120 calls a year. Mostly all these calls are smells and bells so the pumps are'nt always used. The pumps are almost always used during drilling. So as a matter of habit I tell the operators to pull the primme if for any reason just to check if its working properly and to lubricate it. I agree that with the modern pumps and primer pumps it doesn't always need it but it does'nt hurt.
Be safe and keep drilling
08-25-2000, 08:37 AM #20Lt OvermyerFirehouse.com Guest
We used to drain our pumps for winter operation. But we found that if you some how failed by getting all the water out of the pump casing, you still had a freeze problem.
Well we have eliminated that problem. When it comes to winter (Indiana), we now run with the tank suction (tank to pump) open and the tank fill open. When chauffer pulls up on any scene (fire or ems or extrication) the pump is placed in gear and water circulates. It is also natural for the warm water and cold water to flow together to maintain a constant temperature....
It also takes alot longer for 750 gals (tank water) of water to freeze, than lets say a cup of water.
Just something to think about if you work in cold climates. Since going to this procedure we have not had any frozen pumps....
Good luck stay low and stay safe...
Lt. Brett J Overmyer
Carmel Fire Department
This is my opinion and not the opinions of the Carmel Fire Department.
08-26-2000, 07:57 AM #21J AlmonFirehouse.com Guest
What works for us: Just crack the valve for the deck gun to allow air to escape while fully opening the tank to pump valve. This is done while the crew is stretching preconnects. By the time they are in position, you've got water and can throttle up. Be sure to close the deck gun valve or you'll have a big mess!
As for draining, we do if the temp is going below 20 degrees. We've not had problems with pumps freezing so much as the valve rods icing over making it almost impossible to open or close anything, especially when it is below zero. We have large second in districts and can make lengthy runs. We had an old tanker that had a habit of dumping water out of the top of the tank, so it would freeze the doors and windows shut. Never had to find the driver, though.
08-26-2000, 05:57 PM #22ChiefDogFirehouse.com Guest
Thank you Lt Overmyer!! You are the only one to say open both the tank to pump AND tank FILL at the same time! This gives the air someplace to go and gets water moving. Moving water does not freeze and keeps the pump from over heating and doing damage.
Remember the sprinkler system class... air holds the water back if you have a closed system. (dry sprinkler systems)
Opening any other discharge besides the tank fill potentially causes OTHER problems.
08-27-2000, 08:38 PM #23TinyladFirehouse.com Guest
It is amaxing how hard people want to make pumping a truck out to be. Turn on the Pump, put water in the pump, put water in the lines, increase pressure. I read an article in Fire Engineering not long ago about this very thing. Something that they suggested (and that I have found works well) is once you arrive on scene, get out of the cab and on your way to chock the wheels, pull the pump to tank and tank fill valves. Chock your wheels and once you are ready jump in the cab and turn on your pump. by now gravity has already put water in the pump. (Remember water likes to stay at the same level.) It has been my experience that you only need to prime when you are trying to pull water from below the pump. Even then you should have some water in the pump.
As far as draining the pumps, we never did that until one of our officers read and article about it. (never hurt before!) Then they discovered that it didn't matter. Most equipment is in a reasonably heated station. And when you are out for a call or what ever your engine is running and keeping it warm. It takes a lot to freeze 750 gallons.
Just my thoughts. Keep safe all.
Be Safe All
08-29-2000, 11:44 PM #24oldrepeaterFirehouse.com Guest
For my two bits the only thing I find with "backfilling" a suction is that you could lose prime if your pump is running at near capacity and pressure. Water like most things takes the path of least resistance which would be the nice large low pressure line, and as it is on the suction side of the pump it would have the same effect as sucking on a straw then removing the straw from the water without capping the suction end. One has to very carefull to feather in the backfill line if they are going to use this method.
Using the primer on the other hand ensures a less than atmospheric pressure on the suction side of the main pump ensuring a good source of water at the main pump inlet.
Besides, Chiefs who cry foul over a replacement primer, got to remember the men on the end of the hose who's lives may depend on a quick pump operator who uses his primer to maintain adequate prime during critical moments. Somehow the costs seem very insignificant by comparison.
Know it, then apply it.
09-21-2000, 07:14 PM #25TXFIRE6Firehouse.com Guest
I guess if you drain your pumps you an prime if you choose to. We never drain our pumps, and in fact its policy to drive with the tank to pump valve open at all times. This eliminates 1 more step when u arrive at a fire. The pump always has water in it, and is always primed. We would use the primer only to draft, however in town we don't even carry hard suction on engine/quint companies.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)