1. #1
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    Post waterous fire pumps relief valve

    I have a question reqarding the setting of the relief valve. should the valve be left in the on position and the pressure set at (ex.) 165psi? or should the valve be returned to the off postion and the pressure fully increased after each use? Pros & Cons Please! Thanks

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    We leave our pressure relief valves in the OFF position set at the highest setting. This gives us the opportunity to come down to the required pressure. (When pumping to aerial ladders for example) If for some reason the relief valve sticks you will be able to pump pressures greater than your preset.

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    Ok, well we don't have a waterous pump, but we do have a hale pump. We leave the pressure set at about 125 psi, for handline safety. now we do change it when the need arises for like a deck gun or something that can use more pressure. we have had it stick a few times, but was able to free it again with a little bit of water hammer like open the tank fill and then closing it real quick but we do not close it all the way, that usually seems to work everytime, but we do cycle it everytime we go out and train with it. which is about every mon. night

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    jmicheal,

    I believe that the "on-off" switch is a four way valve. It's been a long time since I read the Waterous manual, so I may be wrong.

    When we had a Waterous pump, we left it in the "off" position when it wasn't being used. I think Waterous recommends this. When pumping the engineer should bring the throttle up a little and then switch the position to the "on" position.

    When the truck wasn't being used, we left it set at about 165 psi. Some departments back the pressure all the way off, but I never saw any benefit either way.

    dfd23,

    the reason your Hale relief valve is sticking may be due to debris. We had a very similiar problem that was corrected by having the relief valve serviced.

    For either pump, I know it is a pain, but review the manuals that came with your pumps. I know in the Waterous manual it covers the Pilot valve.

    Hope this helps.

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    The waterous manual Recommends that you leave it set to the pressure that you commonly work at. You dont screw it in all the way because that tightens a spring and may cause it to develope memory. You dont unscrew it all the way because when you turn it on the valve will open and you will lose pressure. It is a very fine thread screw and it takes along time to get it to the pressure that you want. So leave it set to where you operate the most common discharge at. Then when you charge that line, open the throttle to get that pressure and then turn on the relief valve and see what it does. Adjust the valve/throttle accordingly.

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    It seems incredible to me there are so many urban legends about something as common as a relief valve, and the operations manual would not be the guide look at the stated EDP's, what a spread

    Yo know what i mean? How man of yu have changed an over stressed spring it a memory? Obviously all the smot bor user would have to due to low pressures required. Why does Waterous and Darley have on/offs and not Hale? Why does Darley have an emergency shutoff and not the other two? Why does one have a strainer and not the other two? Why do two have open and closed lights and the other just an open?

    All three are what 40 years old? You'd think we would have figured them out by now.

    [ 12-17-2001: Message edited by: the7tower ]</p>

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    The pilot valve that controls the relief valve can be left in a pre-set position; (the spring has no memory). This position then has to be adjusted when the pump is connected to a pressurized water source. The purpose of the on-off control is to take the relief valve out of operation if pressures higher than 300 psi are required. The relief valve should be used any time 2 lines are deployed and the pilot valve should be set to about 5 psi above the intended discharge pressure. Exercising the relief valve and keeping the strainer clean will help to keep the relief valve system operating as is should.

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    Quote Originally Posted by fire127797 View Post
    We leave our pressure relief valves in the OFF position set at the highest setting.
    This can over stress the spring and weaken it. Compressing a spring will not wear it out. Compressing it too far just once can.
    Last edited by txgp17; 04-24-2008 at 06:27 PM.

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    Waterous valves have an on/off switch because when they fail they fail in the open position and dump all your pressure. Hales don't because their design causes them to fail closed. (I am not familiar with Darley's)

    All PRV's stick when not used, the key to keeping them working is to use them. Waterous need to be cleaned and flushed once in a while, RTFM (read the freaking manual) to learn how. Hale's have a strainer, but its part of the plumbing and not normally cleaned, though if you're having problems you may want to check it, again RTFM.

    Leaving a PRV set to max will not damage it, but since the valve is not working it will stick in the closed position and not work when you need it.

    Waterous valves can be damaged by over tightening the pilot valve (there's a needle valve at the tip).

    Personally I like the Waterous, it allows you to preset your working pressure and with a flip of a switch turn it on/off, though normal wear on the on/off valve will cause it to start opening when you don't want it to.

    Important note, all normal PRV's work by differential pressure and as I recall the minimum pressure differential is like 70lbs between intake and discharge for it to work. So if you set the PRV to say 150psi on tank water, then hook to a hydrant with 80psi residule, the valve will not relief until you hit 230psi! Could be quite a surprise if you are on the end of the line. If you try to set the PRV to 150 on the same hydrant it won't work because the differential is less than 70 lbs.

    Hope this answers your questions.
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    Here's a little manufacturer's info.....


    Extend the Life of Your Pump with
    Tips from the Pros.

    Taking Care of Your Discharge Relief Valve
    The discharge relief valve system is one of the most important safety features on your Waterous fire pump. The relief valve is designed to keep dangerous pressure surges from injuring firefighters on hoselines. The system consists of two components: the pilot valve, which is mounted to the pump panel; and the relief valve, which is mounted between the pump intake and discharge fittings. The pilot valve manages the system by sensing discharge pressure and controls the opening and closing of the relief valve. The relief valve directs water from the discharge of the pump back into the intake of the pump when pressure surges occur.

    Do you have a discharge relief valve that is sluggish or seems to stick open or closed? Chances are the relief valve is not worn out, it actually hasn't been used enough. Just like the human body, a relief valve needs to be exercised in order to stay in good shape. It doesn't take a lot of time. In about ten minutes per month, you can perform some easy exercises that will help keep your relief valve system working and keep your firefighters safe.

    Just follow these simple steps:

    Engage the pump, begin circulating water, and increase pump discharge pressure to 150 PSI.
    With the pilot valve OFF, remove the strainer assembly. Then clean the strainer and the orifice in the end of the strainer rod.
    Turn the pilot valve ON and OFF several times. Water should flow from the opening in the ON position and stop in the OFF position.
    Check the strainer o-rings and replace if damaged.
    With the pilot valve in the OFF position, replace the strainer assembly (finger tight only).
    With the pilot valve OFF, turn the large pilot valve handle counterclockwise until it stops.
    Slowly turn the pilot valve ON. The relief valve should open (amber light) and pump discharge pressure should drop below 90 PSI.
    Slowly turn the pilot valve OFF. The valve should close (green light) and pump discharge pressure should rise back to 150 PSI. Repeat steps 7 and 8 until the system responds quickly when turned ON and OFF.
    Reset the pilot valve to the desired setting and decrease engine speed to idle.
    Something else that you can do to help keep your relief valve and other pump systems operating well is to drain the pump and flush it with clean water once a month. This will help flush deposits of sand or other foreign materials out of the pump and help prevent the premature failure of moving parts and seals. By performing some very simple maintenance on a monthly basis, you can see how easy it is to keep your Waterous fire pump and accessories running like a well-trained athlete.

    If you have any questions regarding this information or need any assistance, please contact us at:
    Telephone: 651-450-5200
    Fax: 800-488-1228
    sales&service@waterousco.com



    http://www.waterousco.com/pdf/specsh...e%20Valves.pdf

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    Default Relief valve pressure differential

    It is true that in order for the relief valve to operate properly, a pressure differential between the intake and discharge sides of the pump needs to be around 70 psi. or greater. However, if (as in the example) you set the relief valve at 150 psi. and hook up to a hydrant with a residual pressure of 80 psi. the differential IS 70 psi. and the releif valve will operate as designed. If the differential is less than 70 psi., the relief valve will still work only it will react sluggishly. It is my experience that when the difference between intake pressure and discharge pressure is less than 50 psi. the relief valve works marginally or not at all.


    Quote Originally Posted by Fire304 View Post
    Waterous valves have an on/off switch because when they fail they fail in the open position and dump all your pressure. Hales don't because their design causes them to fail closed. (I am not familiar with Darley's)

    All PRV's stick when not used, the key to keeping them working is to use them. Waterous need to be cleaned and flushed once in a while, RTFM (read the freaking manual) to learn how. Hale's have a strainer, but its part of the plumbing and not normally cleaned, though if you're having problems you may want to check it, again RTFM.

    Leaving a PRV set to max will not damage it, but since the valve is not working it will stick in the closed position and not work when you need it.

    Waterous valves can be damaged by over tightening the pilot valve (there's a needle valve at the tip).

    Personally I like the Waterous, it allows you to preset your working pressure and with a flip of a switch turn it on/off, though normal wear on the on/off valve will cause it to start opening when you don't want it to.

    Important note, all normal PRV's work by differential pressure and as I recall the minimum pressure differential is like 70lbs between intake and discharge for it to work. So if you set the PRV to say 150psi on tank water, then hook to a hydrant with 80psi residule, the valve will not relief until you hit 230psi! Could be quite a surprise if you are on the end of the line. If you try to set the PRV to 150 on the same hydrant it won't work because the differential is less than 70 lbs.

    Hope this answers your questions.

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    Quote Originally Posted by bupser View Post
    it is true that in order for the relief valve to operate properly, a pressure differential between the intake and discharge sides of the pump needs to be around 70 psi. Or greater. However, if (as in the example) you set the relief valve at 150 psi. And hook up to a hydrant with a residual pressure of 80 psi. The differential is 70 psi. And the releif valve will operate as designed. If the differential is less than 70 psi., the relief valve will still work only it will react sluggishly. It is my experience that when the difference between intake pressure and discharge pressure is less than 50 psi. The relief valve works marginally or not at all.
    ...............................

    Fm1
    Last edited by FIREMECH1; 01-25-2011 at 02:49 PM.
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    Quote Originally Posted by the7tower View Post
    It seems incredible to me there are so many urban legends about something as common as a relief valve, and the operations manual would not be the guide look at the stated EDP's, what a spread

    Yo know what i mean? How man of yu have changed an over stressed spring it a memory? Obviously all the smot bor user would have to due to low pressures required. Why does Waterous and Darley have on/offs and not Hale? Why does Darley have an emergency shutoff and not the other two? Why does one have a strainer and not the other two? Why do two have open and closed lights and the other just an open?

    All three are what 40 years old? You'd think we would have figured them out by now.

    [ 12-17-2001: Message edited by: the7tower ]</p>
    Hale DID. They substituted a push button for all that schit. Hehe T.C.

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    Quote Originally Posted by Bupser View Post
    However, if (as in the example) you set the relief valve at 150 psi. and hook up to a hydrant with a residual pressure of 80 psi. the differential IS 70 psi.
    Sorry, No. If you set the 150 psi on tank water your PRV will not open until 230psi. The set point of non PRV's is differental, not actual pressure (except for Hale TPM's). You missed my point, if you set your PRV on tank water it will not be the same on pressurized water supply, you must reset the PRV to match the current differential, and that needs to be an on going operation for the pump operator, if operating at a large scene and your residual drops so too will your set point.
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    The 2008 revival of this one didn't last long, how long will the 2011 attempt go?

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    Its quite a bump of one of my ancient posts, was a little surprised when I got the email on this thread...
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    Since y'all re-opend this, I'd like to add a caution about a Watrous relief. Do Not leave the 4-way valve in the ON position and then back off the "football" to zero, and then shut down the pump. The main relief valve closes under pressure from the pilot assembly. By backing the setting to zero, the main valve is open at an idle and then if you take the pump out of gear, the valve remains open. Now park the engine for a couple of weeks and the O-rings will be stuck to the valve bore wall. Since the valve needs pressure to close, but it is completely open and stuck there, you won't be able to build more than about 70 psi. pressure. Wind up the pump (1200 rpm) and try slamming a discharge open and shut to create water hammer that might loosen it up and cause it to close. Your biggest enemy is a lack of use.

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