04-25-2001, 09:04 PM #1phyrngnFirehouse.com Guest
Wet Pumps vs. Dry Pumps...Need your help
To any expert pump operators out there. I need some information to present to someone on my department to defend myself. We have a Hale 1250 GPM single stage pump, and my colleague says that we need to drain the pump after every use, otherwise we're "hurting" it. I've always been told to keep water in the pump, it will allow things to move alot faster on the fireground. After a recent fire, I told the Pump operator to go ahead and leave the pump "wet" and my colleague "flipped out" because we didn't drain the pump. Are there any viable reasons as to whether or not to keep the pump dry? (We keep it dry during the winter for obvious reasons, but during the spring and summer, we don't have the problems of pump freezing.)
04-25-2001, 09:20 PM #2ADSN/WFLDFirehouse.com Guest
The department I work for is in Northern Illinois, where it can get down to -30 below 0 windchill, and we keep our pumps wet. We just recently got Lake Michigan water but before that we had iron rich well water. Even with poor water quality we didn't have problems with water left in the pump.
The water in the pump actually keeps the packings in better shape by not letting them dry out. The problem with the dry pump is that in winter it can actually freeze faster, often times valves leak water and the leaking water will freeze much faster than a full pump.
Their is also the matter of getting into operation quicker. And if drafting you have less air pockets to worry about.
04-25-2001, 09:29 PM #3jpchevFirehouse.com Guest
Hi PHYRNGN, I started firefighting 30+ yrs ago in a small town combination Dept. we had mostly 1000 GPM Hales but several others also. WE NEVER DRAINED A PUMP, WINTER OR SUMMER, and never had a problem. I moved to a larger town with long response times (15 + minutes station to scene) and the policy was always drain the pumps in the winter so they would not freeze. I had many cases of what little water remained, like between the valve and the port cap, frozen solid! A few years ago we had a new Company start servicing and testing our pumps and they said.."why are you draining the pumps in the winter? The pump full of water at station temperature takes a lot longer to freeze then the empty pump, leave it full. We service pumps in NH and ME where it is a lot colder than in RI and they don't drain their pumps." So we stopped draining and guess what? No problems, packings and seals stay wet and sealed, people don't forget to prime the empty pump and burn the packing and sleeves, water comes faster and we have not had a freeze up yet. It is SOP when you reach a scene in freezing weather to engage pump and circulate water, more to keep the plumbing from freezing than anything. Hope this helps. Capt. John C. HJFD
04-25-2001, 10:29 PM #4phyrngnFirehouse.com Guest
Thanks, folks...just the ammunition that I need...
04-26-2001, 10:30 AM #5Smokeetr4Firehouse.com Guest
There is no reason to drain the pump unless like you stated, the temp is below freezing. In all other cases the pump should remain wet in order to facilitate immediate pump capability. If your powers that be still want you to drain the pump after every use, try his. Open you tank to pump valve before your next pumping operation. This will prime your pump in a hurry allowing you to continue the operation without delay. Staylow-you go..stay high you die....Stay safe.
04-26-2001, 02:41 PM #6CAPTAIN WHOFirehouse.com Guest
04-27-2001, 08:55 PM #7ParafiremedicFirehouse.com Guest
Your best defense in this matter would be to call the pump's manufacturer, and find out what they recommend. Coures they will say to keep the pump full at all times. This is mainly to keep al the seats, and packing from drying out. You'll also find that there is a allowable leak rate for the packing on the pumps, ie: so many drops per minute. Another thing to consider is lossing the prime of the pump. I know someone out there will say all you have to do is open the tank to pump valve, and problem solved. This is not allways true. You have to have somewhere for the air in the pump case to go, and out the end of the hose isn't the best place for it to come out. As for draining a pump. Bet your buddy that you can't completely drain a pump by simply opening the pump drain valve. Try it, open the drain valve and wait for the water to finish pouring out, now with the drain valve still open, open you deck gun valve, followed by the 2 1/2" valves. Sit back and watch the stream of water flow out. This is because the water at certain parts of the pump manifold will be held in place by a vacume, until you let air in from other places, well ok that and the deck gun will still have some water in the riser above it's valve.
04-29-2001, 02:59 AM #8eyecueFirehouse.com Guest
How long are you letting it sit with water in it between operations? Is it mechanical packing or rope? If you are going to run dry pumps then on the way out of the station you could pull the tank valve open so that it fills on the way to the call. IF you are running dry for long periods of time and have rope packing then you should get under the pump and apply oil to the area around the packing while pulling a dry vacuum test on the pump. This will suck some oil under the packing and around the shaft to keep the seal good and the packing from drying out. This is pain in the butt. Running wet pumps is not a problem unless you are parking the rig outside for long periods of time in freezing weather.
12-04-2002, 12:45 AM #9
BUMP TO THE TOP - THAT TIME OF YEAR AGAIN
How's it done in your department?
12-05-2002, 12:56 PM #10
- Join Date
- Jul 2001
We leave our pumps wet year round and it can get awfull cold in Canada. If we are on scene for a while we circulate the pump to keep things from freezing up. We also keep two spray bottles on board in the winter, one with plumbing antifreeze and one with methyl hydrate. At the start of each shift the operator will ensure the port caps and gates are sprayed.
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