How do you prevent vacuum? With a supply intake. Why would you leave the tank to pump open?
When do you shut the TANK to PUMP?
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The Only time the Tank to Pump should be closed is if you are drafting. Most pumps have a flapper valve in the intake that will shut the tank to pump off once a pressurized water source is hooked in. Also, As soon as that water source is hooked in, the booster tank should be refilled, This water could save the life of your crew. This is also why the Tank to pump should not be closed! If something happens to your water source the pump will automatically switch back to your on board water. That’s 750 Gallons (For most of us in ECFR) of water to get your crew backed out until the problem with the water source can be fixed! So, The short answer is NEVER, unless you are trying to draft.
Thank You, Lt. Bush. Excellent answer. I wish everyone in the FIRE SERVICE could respond this way. To many firefighters are trained to close it “tank to pump” after getting a supply. Thanks for posting a GREAT answer.
Thanks to Lt. Van Matre and Lt. Harrison for preaching this in the First 24 hour Pump Ops Class they put on several years ago!
I have to disagree with this. The Tank to Pump should be closed as soon as the water supply is established. A good pump operator can reopen it if something happens to the water source. How do you know something has happened to the water source if you leave Tank to Pump open. As soon as the water source fails, the flapper you mention allows water from the tank to take over and begin emptying your tank, once your tank is empty( with no water source) you interior crews are screwed. Also, I have seen someone leave Tank to Pump open after they got their water supply and in the scenario, there lines increase in size to the point the water tank actually supplemented the water source and emptied their tank. It is my opinion to close Tank to Pump as soon as the water supply is established.
Thanks for Posting Steven. I look forward to more post from you.
Steven – Great post. I’m with you. I have always practiced closing the TTP valve once the water supply is established. I always stay close to my engine while crews are inside and engaged operationally. If the water supply drops out I can hear the pressure governor start to rev up to compensate for the lack of pressure and quickly return to the panel to open the TTP, close the intake valve, and let my crew (and the IC) know there is a supply issue and that they are working on tank water. I understand there may be a slight delay opening the TTP but I feel this allows us to “catch” the supply problem ASAP and maximize the interior crews remaining water to defend their position and protect themselves.
This has been a point of discussion in our department too. Folks seem to feel very passionately about doing it one way or the other and I certainly I see merit in both approaches but for me I prefer to work the way I have described above. A good discussion for sure.
Wrong. A good pump operator is not staring at the compound gauge 100% of the time. He is doing all the other things that separate a good operator from an average operator from placing tools in strategic locations, throwing ladders, and all the other stuff a good operator should do. Never close the tank to pump and never let that compound gauge get close to zero. The tank to pump is your crew’s safety buffer. If you lose your supply you will hear it in your trucks RPMs and you can’t go fix the problem or call for crews to back out. A good operator can look at his tank level and compound gauge as he goes from one task to the other. The tank to pump will react immediately when you lose that supply. No surge in pressure and no water loss at the nozzle.
Damion, I am confused at you reply, are you for or against closing Tank to Pump? You state a good operator does other stuff, I agree, I have thrown ladders and helped pull hose for the firemen. You stated that with it open, there will be no pressure loss or loss of water at the nozzle. How then, will you know you are operating off the tank, if you are away doing other things. My engine has a pressure governor, when the supply drops off, the governor increases the RPMs and I hear the truck and would realize something is happening, that is when I check my gauges and would open Tank to Pump. This is a great topis and both ways have Pros and Cons. But, ultimately, we need to train our Pump Operators to be aware of what is going on with your truck. “Set it and forget it” is a thing of the past. Look forward to hearing more about this
I am all for leaving it open. If you have a pressure governor and you lose your supply your RPMs will increase even more. You are no longer having a hydrant to assist your truck so the truck has to work harder. In either case you will hear the change. You don’t set it and forget it. You set it and check it often. Too much can go wrong if you allow the crew inside to lose pressure. Even if its 10 to 20 seconds.
PS. I didn’t say they wouldn’t have a pressure loss. That all depends on how much water you are flowing, if you have a governor or if your relief valve is set. I said a pressure surge. Example, you would leave the tank to pump closed. If your supply gets compromised the nozzle loses all water. Most, once the brain computes what has happened will grab the tank to pump without throttling down and give the nozzle a good surge in pressure.
Steven,
You said “Also, I have seen someone leave Tank to Pump open after they got their water supply and in the scenario, there lines increase in size to the point the water tank actually supplemented the water source and emptied their tank”
A good pump operator would NEVER let this happen. Any good pump operator should be able to tell the IC yes or no very quickly if he can pump another line or not. If you are pumping more water than you are taking in you have way bigger issues than to leave the Tank to Pump open or closed! Pump Operators MUST have the Guts to tell the IC NO when asked for more lines if the water supply will not sustain the increased load! In your scenario above, if you would have had the Tank to Pump Closed you would have had a bunch of under pumped limp lines. So, Obviously there needed to be either a reduction in the amount of water being flowed OR a secondary water source secured PRIOR to the increased flow. If you cannot maintain 20psi residual on your intake then you have no business adding more lines and if its robbing from the tank I can promise you there was not 20 residual! These are just my opinions and I am not trying to knock anyone, but it is unacceptable to lose water even for a second!
Well said
How do you know if you have a water issue you ask? Well, well well. The intake guage would read 0 or close to it and if you had an electronic governed engine, it would throttle up to keep the same pressure. Outside of drafting, freezing climates, and maintenance, the tank to pump should never be closed.
Trainers in various departments in the past have treated the tank to pump issue as part of a “5 step” type of memorization of initial pump operation. “if you don’t close the tank to pump you could losing some extra pressure” that’s what i heard before…. Agreed leave it open, it won’t hurt anything…same with the recirc valve, if you are only waiting momentarily for water transaction and pump isn’t sitting for long extended times leave it closed!…
To close the TAMK TO PUMP with water in the tank, is like telling your Bank to not provide you overdraft protection. Why not keep your tank water available for some cray emergency and/or the ability to drop down to ZERO on intake gauge.
Keep it open!, the problem with closing the TTP valve is the safety backup for the crews inside is lost! You cant count on a supply line or hydrant 100% of the time, S!*T happens, loss in pressure from another hydrant being opened, car drives over the supply line, hose disconnects, ect… The problem with closing the TTP is remembering to re-open it when its needed! I don’t care how much you train, when your crew members are screaming on the radio “WE NEED WATER NOW!” you are going to forget something. Keeping it open takes that problem out of the equation.
On my truck the TTP valve auto closes and the tank fill can not be closed 100%. The truck is designed to work that way, it closes TTP and keeps the tank full at all times by robbing small amounts of water from the intake. Its all about knowing your truck and knowing it well! Keep the intake above 10psi and no problems should exist! Know how to say NO! to more lines when asked if the intake cant handle it!
word
You gotta leave it open. All the talk about hearing a change in RPM if your not constantly looking at the gauges seems to be distorted. If I lose the water supply on my Engine my RPMs will go up even it the TTP is open. That is when I should notice the problem. I might not be standing right next to the truck for what ever reason, and are the people who say keep it closed telling me they are ok with a loss of water supply inside for even a second?(it’s gonna be longer than a second) It seems like a no brainer to just prevent that loss of water and possible dangerous situation by just leaving the TTP open. I am sure before the one way clapper valve was installed on these pumps there was a real reason to close it. Technology has advanced and now all apparatus built in probably the last 15yrs has a one way clapper valve. My question is why do we struggle with change so much?
Progress impeded by tradition!
also, it reminds me of the monkey story from the book “buddy to boss” when the monkeys keep beating the other monkeys and they don’t know why! Chief Ike, I know you know what I’m talking about.
Monkey beaters LOL!
Interesting discussion! A bit of history on this topic: Long ago the check valve in the tank suction line was an option and many apparatus were not so equipped. If you left the tank valve open, hydrant pressure would backfeed into the tank until it overflowed. Hence, the rule to always close the tank valve as part of the changeover to a hydrant supply. After check valves became standard, we continue to do the same thing (but forgot why). If the engineer is at the panel, I am not sure if it makes a big difference. However, if not, the argument for having it open has a great deal of merit. In either case, it is critical that the engineer monitor what is happening and alert the crew(s) inside if there is a loss of water supply. On a related note, if operating from tank water, what is your threshold for withdrawing the interior crew(s)?
I will be posing the tank valve question to our members in the comming week. Hopefully some thoughtful argument:)
Thanks ED Great Stuff!! This is how we make sure we are on the right track. Debate is good and we can learn from it. History and the Future both matter.
I will ask this, what if the output exceeds the hydrant with the TTP open? I hear everybody talking about pump operators doing other things and not staring at the panel. I have seen it ( in training ) where the tank was emptied, even with a water supply established, because the operator failed to watch his compound and his TTP was opened. What then? Empty tank + interior crew with no water = not good. Just sayin.
Yep it could happen. That operator may be doing other things but he still has to keep an eye on that panel. The loss of your water supply is usually without warning and most likely sudden. Your tank water being depleted has several warning signs like Compound gauge less than zero and tank gauge moving down. Like I said never close the tank to pump and never let the compound gauge get close to zero.
know when to say NO! to extra lines!!!!
All the discussion so far has been about pressure governors. What about this? When you are pumping a conventional throttle with relief valve and you are operating off a water supply, should your Tank to Pump valve be opened or shut? I say shut. If it is left opened and like we discussed, you lose your water supply, your tank will take over. But, if you are not aware this has happened the first sign of a problem will be when the tank is empty. This to me is more dangerous than a temporary lose of water. Meaning, if I close my TTP when operating on a water supply and we lose the water supply, the interior crews will ask or notify you and you can open it and allow them a possible safe retreat with tank water.
Dude just go out to your training pad and try it for yourself. If your guys have to get on the radio to ask why they don’t have water that is too long. You should never ignore you panel that long. Leave it open and your red flag should be when that LDH goes limp or your first light for the tank gauge drops.
Dude, I’ve done it several times. Its more dangerous to close it. Talk about air time, they will be dead because you didn’t get their tank water back, because it is empty. You say thats too long to be away from your panel, we have 500 gallon tanks and we flow 1″ tips. So if we have 2 lines flowing and we lose our supply that is just a minute of time to empty our tank. So you’re telling me you are never away from your panel for more than 1 minute. You must be really good at throwing ladders and placing tools in strategic places if you are not gone for than1 minute. I don’t think that is possible.