1. #1
    ffdoneng62
    Firehouse.com Guest

    Question relief valve settings

    hi i was wondering what everyone sets there relief valves at ? my dept. sets the relief valves @ 140-150 psi and is that the"norm" for settings

  2. #2
    capt3211
    Firehouse.com Guest

    Wink

    We run approx. 120 psi due to using low pressure nozzles (125 gpm/75 psi) on preconnects than increase with bigger lines.

  3. #3
    WRENCH
    Firehouse.com Guest

    Post

    got to agree with the Capt. not knowing your manning or your sop"s , I would dare say that you do not have enough manning to handle that kind of pressure on an initnal attack line.Very hard to handle, unless your talking hi rises or really long stretches 120 sholuld be good and on short car fire lines 100 ft , 80 to 100 psi should be adequate. Purists will argue other wise but lets talk real world. And while your at it ,do you preset your relief valve? That should start a debate!

  4. #4
    FiRsqDvr45
    Firehouse.com Guest

    Cool

    We run ours at 120 also but with the 200 and 250 foot preconnects we are getting only 80-90 gpm from them at those settings, which I think defeats the purpose of upgrading from 1.5 to 1.75 hose. As far as the question of whether we should preset the PR or not I can go either way. I would hope that the person running the pump would be able to set it appropriately for the task, if not why are they running the pump? A preset is a good base I guess to allow 1 or 2 people to stretch and start a flow but the pump operator and the crew need to comunicate quickly so the pressure can be set to get the flow needed for the fire. Sometimes I thin kit is just left there thru the whole fire limitiing the lines capabilities, kinda like when we have a "Christer" and no one remembers to break down the 1 inch tip to a bigger size on the deck gun or ladder pipe. Training and repetitive practice are key.

    ------------------
    FF/EMT Jay Ellingson
    Newington,NH FD
    Be Safe!

  5. #5
    Bob Snyder
    Firehouse.com Guest

    Cool

    We generally run hand lines at 125-135 psi and the relief valves are set at 135 psi...enough to allow the pump operator some room for adjustment, but not enough to knock anyone over if something goes wrong.

  6. #6
    LHS
    Firehouse.com Guest

    Post

    In the past we mounted a yellow light on the cab roof attached to the relief valve open light. The relief valve was preset at 200 psi to flow 245 gpm out of 150 feet of 1 3/4" Angus Chief hose with a fog tip. The engineer simply throttles up till the open light came on and then took another 1/2 turn of the throttle to keep the pressure up when someone finally started flowing water. The relief would simply recirculate water and maintain the pressure. The revolving light told everyone on the fire ground the rig was pumping the right pressure. We label the relief valve "pre-set, open 7 1/2 turns". That allows checking the relief valve setting in the station with the pump off. You simply turn the knob until it is closed then open 7 1/2 turns to properly set it to 200 psi in our case. It works with all makes of pumps, although the number of turns is different, I think Hale was 20 turns.

  7. #7
    Dalmation90
    Firehouse.com Guest

    Cool

    Just an observation...I'm kinda amazed at the pressures the handlines are being pumped at!
    I guess I'm just used to running 150psi unless someone says otherwise. And nowdays our primary attack truck is almost always pumping at 200psi -- yep, line is pretty stiff, but it makes good looking Class A foam at that pressure.
    Implicit in that of course is the relief valves are set at 200psi initially.

  8. #8
    ffdoneng62
    Firehouse.com Guest

    Cool

    Well this is what I was told that 140-150 psi
    was NFPA standard or should I say recommended this I was told by one of the lieutenants on my dept.

  9. #9
    Dalmation90
    Firehouse.com Guest

    Cool

    Ran the numbers again...
    Pump at 150psi delivers:
    135gpm through 150' of 1.75" with 100psi Nozzle pressure
    95gpm through 200' of 1.5" with 100psi N.P.
    (Gosh, corresponds with the flows the nozzles we keep on each put out!)

    I guess I can see sub-150psi pressures if you run smoothbores or low-pressure fog nobs...but with standard 100psi nozzles?



  10. #10
    Romania
    Firehouse.com Guest

    Post

    I tend to pre-set my relief set at just over 150psi. We use automatic nozzles and it does work out to be 95gpm for our 200' 1-3/4" preconects. On our truck, If I need to flow foam, I can turn our relief valve 5 times and it will now be set at 200psi. If I turn it 4.5 times the other directions I am at the pressure I flow the car fire line at (100' 1-3/4").

    ------------------
    Alan Romania, CEP
    romania@uswest.net
    IAFF Local 3449

    My Opinions do not reflect the opnions of the IAFF or Local 3449.



  11. #11
    WRENCH
    Firehouse.com Guest

    Post

    presetting relief valves is all well an good but on the newer pumpers with electronic relief valves or pressure govs it is a mute point as you are ramping up from zero every time you pump. on the older hale reliefs, from a maintainance point of veiw it is not good to preset as it can cause a set in the springs. It is then necessary as you all know that working the relief in the full range is essential on regular basis to prevent sticking and the like. by not setting the valve you are working it each time. when I started we were taught to preset at 150 in case the spring broke and some guys were to dumb to remember. if the spring breaks at 150 or higher do you really want to be operating the pump any way with no control over the pressures to the lines? counting turns on hales is agood idea, a qualified operator should know his equiptment. by not presetting he would be adjusting to the situation at hand and not get into the habit of just charging the line and forgetting to set to a pressure that is really called for

  12. #12
    D. Anderson
    Firehouse.com Guest

    Post

    I was wondering the same thing as Dalmation90 the first time I read this post and wondered if I was missing something. We pump our preconnect at 175 PSI (250 feet 1-3/4 with automatic nozzle) and set the relief valve at 1/2 turn over that, not at a pre-set value. The backup line setup we use is 2-1/2 to a wye with 1-3/4 so it is pumped at a lower pressure because of the lower friction loss, and in most cases your relief valve setting is just left at the attack line pressure because it's higher most of the time.

    I should add that like Wrench said we leave our relief valves set all the way closed and bring them down to the operating pressure used in each situation. If the lay is too long for our preconnect we go to the 2-1/2 deadlay and the pressure would be different.

    Our new pumpers all have the "Fire Commander" governor on them but were also delivered with manual pressure relief valves, and there is some discussion as to why you should or shouldn't set the manual one when using the "Fire Commander". Any thoughts on that out there.

    The new rigs also have intake relief valves that you can set in the field, what do you guys have yours set at?

  13. #13
    DD
    Firehouse.com Guest

    Post

    Intake relief set at 75 p.s.i., but we have to adjust it to about 120 p.s.i. for about 1/4 of our hydrants.

  14. #14
    Joseph Mowery
    Firehouse.com Guest

    Post

    We set the Piston Intake Relief valve at 80psi.

    We pump at 130psi to 200' of 1 3/4in house using 75 psi nozzles. If we need more/less flow it is called back to the pump operator and the pressure is adjusted.

  15. #15
    oldrepeater
    Firehouse.com Guest

    Post

    Gotta agree with "Wrench" I feel it is a very bad idea to rely on "number of turns" in order to rely on pump relief settings.
    Mechanically the spring which controls the relief piston, wears with each opening of the relief. It should be good maintenace practice to actually set up and test the relief through it's paces in order to ensure the setting placed on the spring is the final pressure setting you want.
    In the interest of safety, starting up the pumper / engine and actually pulling a precon to check during practice or a maintenace period is far better than "guessing" where the pressure may or may not be during a holy sh*tter.



    [This message has been edited by oldrepeater (edited March 24, 2000).]

  16. #16
    LHS'
    Firehouse.com Guest

    Post

    So who has ever had the spring break? Who really uses the relief every call or sets it every call? Survey says? Our pumps have lifetime warrantees, includes 100% parts. and yours?

  17. #17
    EnjineCaptain
    Firehouse.com Guest

    Lightbulb

    Maybe your pumps have a lifetime warranty, but taking that truck out of service to repair something that operators misuse is unacceptable. The others are correct, unless you operate your relief valve regularly (i.e. no less than daily, and while actually flowing water), the spring in the pilot valve will develop a "memory" and not operate properly.

    Properly operating the relief valve means that the pump operator understands how it functions and is able set it for the current operation. I understand that instructing your personnel to set by a certain number of turns is simple, but to me that means that the operator does not have a thorough knowledge of how the pump functions or how to trouble-shoot any problems that may occur. I would not feel safe.

    We flow 200ft x 1 3/4" handlines of low friction Conquest hose with automatic nozzles at 150psi to give us 125gpm+.
    A 2 1/2" or 3" with wye down to 1 3/4" lines, starts at 170psi depending on how much of 3" is down.
    The relief valve would be set about 3/4 turn past the required pressure for a given operation. We do not preset the relief valve for the reasons I described.

    ------------------
    I'm glad to hear from any of you.
    EnjineCaptain

    "This isn't what we do, it's who we are!"

  18. #18
    WRENCH
    Firehouse.com Guest

    Post

    LHS, I hope you are being facticous. Yes we did have a spring break once, fourtunatly it was not in the middle of a fire call but on a sunday check. I'll cnside yes most times you do not need to set it, but as enjine capt said it is uncalled for. how would you justify an engine breaking down and being sued for lack of maintainance, and it does happen.sounds like a case of lazy operators or very poorly trained ones.

  19. #19
    bfd1071
    Firehouse.com Guest

    Post

    Larry....I know you guys have monster rigs in your dept, but what you say does not make hydraulic sense to me. You state that you set you relief valve at 200, to flow 245 gpm out of 1.75 line, at 150 feet. Is this not a bit much? Why not decrease you Engine preasure with going to a larger line and keeping with the same discharge flow.
    I'm not an Enginemen, but this makes a little more sense to me, how about the rest of you?

    [This message has been edited by bfd1071 (edited March 28, 2000).]

    [This message has been edited by bfd1071 (edited March 28, 2000).]

    [This message has been edited by bfd1071 (edited March 28, 2000).]

  20. #20
    LHS'
    Firehouse.com Guest

    Post

    ... Is this not a bit much? Why not decrease you Engine preasure with going to a larger line and keeping with the same discharge flow.
    ..

    Because it works well, drags well, why increase the drag weight or increase the number of firefighters to move the line through the building on a pump designed to pump 10 to 400 psi and run only 250 rpm higher, we or you won't wear the rig out, the hose doesn't burst. We are not afraid to throttle up.

    If someone else wants to pull a 3 inch line the same length and pump 55 psi all the power to them just add a few more guys to the line.

    Are you taking or is anyone taking their rigs out of service due to relief valve failure? Are you reporting it to NFPA?

    Is there a reason why you wouldn't run your rig daily? This is an emergency business and certainly you check your rigs daily which exercises the spring.

    So the guy who presets the pump and knows the number of turns can't possibly know how to operate the rig and problem solve?

    Lots of FD's being sued for lack of maintenance? Who where why? SO your spring broke and you don't pre-set your relief valve. Did you buy that make of pump again? Why do you have to put the truck out of service? Like someone said you need to know the rig, 30 minutes in the station max and the spring is history and a new one would be installed.

    ------------------

    Just one persons opinion, based upon seeing and doing for 25 years, do't get riled up, all fires go out everywhere even if the FD doesn't show up, if you don't agree with the answer just pretend you didn't read it, apply whatever you think works.

  21. #21
    bfd1071
    Firehouse.com Guest

    Post

    Larry.... do not get on the offensive. People are just telling you they do not agree with your "71/2 turn" theory. If it works for you, great, but it should be checked and done correctly everyday.


    ..Because it works well, drags well, why increase the drag weight or increase the number of firefighters to move the line through the building on a pump designed to pump 10 to 400 psi and run only 250 rpm higher, we or you won't wear the rig out, the hose doesn't burst. We are not afraid to throttle up.

    how much less will the 1/34 be at 245 gpm in weight with the same amount of water in the 21/2? It is still 250 gallons correct. We drag our hoses dry, when we need the water we charge it. What is your friction loss in this 1.75 hose? It must be out of sight, really making your pump work harder then need be, and so with the guys on the line. As for the hose bursting....tell that the the poor guy in Ga.

    ------------------
    ** The opionions are mine and mine alone, they are not that of my dept or the local**

  22. #22
    LHS'
    Firehouse.com Guest

    Post

    ...how much less will the 1/34 be at 245 gpm in weight with the same amount of water in the 21/2?...

    The answer is more than twice the weight.

    ...It is still 250 gallons correct. ...

    No

    ..We drag our hoses dry, when we need the water we charge it...

    That is nice but the weight in both cases is double the 1 3/4".

    ...What is your friction loss in this 1.75 hose?...

    If friction loss puts out fire then use a 5 inch handline at 250 gpm.

    Our loss is 66 psi per 100 feet.


    ...It must be out of sight...,

    Define out of sight. Your FD needs to pump a ladder pipe at 250 psi to flow 1000 gpm 50 feet from the siamese.

    ...really making your pump work harder then need be...

    Gee, 250 rpm more, that will kill it?

    >>> and so with the guys on the line. As for the hose bursting....tell that the the poor guy in Ga...

    Like I said our hose does not burst. Do you have some inside info on Ga? What hose were they using? Did they follow NFPA 1962? Was the hose tied off, did they use the non-pump panel discharges? Did they use a gate valve with a pin hole? Did they bleed the air? Did they keep the work area clear? Did they use a hose test machine or a pumper? Did they exceed 300 feet?


    ------------------

    Just one persons opinion, based upon seeing and doing for 25 years, do't get riled up, all fires go out everywhere even if the FD doesn't show up, if you don't agree with the answer just pretend you didn't read it, apply whatever you think works.

  23. #23
    bfd1071
    Firehouse.com Guest

    Post

    Larry....your doing it again, your getting all upset about someone that questions you. If you do not like some questioning you, do not post online. I do not agree with your theory on the 1.75 line. I do not agree with alot of what you say and your tactics. From the 2 academies i have been too, both have told me that flow above 150 gpm in the 1.75 hose is unsafe and foolish. I seem to remeber that above this flow, you get Turbulant water flow which increases friction loss, makes the pump work harder. I know your magazine showed all these test on the 1.75 hose and how you put one guy on the line OUTSIDE a building and played with the water. By the way...we do not run at 250 on our ladder pipes. Infact..we try not to go above 150 ep.

    Try not to get all offensive when people question you. Remeber what happened to you on the AOL boards.

    ------------------
    ** The opionions are mine and mine alone, they are not that of my dept or the local**

  24. #24
    Wills
    Firehouse.com Guest

    Post

    We set our a 150. That seem to do the job and I adjust when needed.



    ------------------
    Take Care,
    Wills

  25. #25
    Dalmatian90
    Firehouse.com Guest

    Post

    >Like I said our hose does not burst.

    Gee, feeling a little God like with omnipotent powers again? Thy shall not burst.
    Gosh, I'd like to say nothing goes unexpected on the fireground, too...not sure many would agree with you in fact or opinion.

    Kinda funny, maybe you should follow you're own signature paragraph before posting.

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