1. #1
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    Default Intake relief valve

    I was looking at a pumper spec and it calls for an intake relief valve built into the pumps suction side. The pumper also has an electric pressure governor. It was suggested to me that because there is a governor, the intake relief valve is not required. I'm not sold on that. Both of these items are new to me, can you shed some light on this? Thank you

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    Quote Originally Posted by GPM1230 View Post
    I was looking at a pumper spec and it calls for an intake relief valve built into the pumps suction side. The pumper also has an electric pressure governor. It was suggested to me that because there is a governor, the intake relief valve is not required. I'm not sold on that. Both of these items are new to me, can you shed some light on this? Thank you
    I believe that is incorrect. The intake relief valve is used to relieve (dump) excess incoming pressure from whatever source. The governor cannot do anything about that. A DISCHARGE relief valve is not normally used in conjunction with a pressure governor, although it can be.

    Intake reliefs are used. Our '89 Quality/Duplex has a Ross relief valve on the intake side. Also, our add-on piston intake valve has its own relief. It has a Barber-Colman governor, and no discharge relief valve.

    Our 2007 Toyne/Spartan has an MIV and two Waterous intake relief valves. One is ahead of the MIV and the other is on the pump itself, much the same as the Ross is on the Quality. Again, since it has an FRC Pump Boss, we did not spec a discharge relief valve and none is provided.

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    Quote Originally Posted by GPM1230 View Post
    I was looking at a pumper spec and it calls for an intake relief valve built into the pumps suction side. The pumper also has an electric pressure governor. It was suggested to me that because there is a governor, the intake relief valve is not required. I'm not sold on that. Both of these items are new to me, can you shed some light on this? Thank you
    The intake relief valve bolted to the pump body on the suction side is required in NFPA to protect the auxillary suction inlets that are not supplied with any relief valves.

    You might be confusing an intake relief valve with a discharge relief valve. They do different Things. A discharge relief valve monitors pressure and opens on the discharge side of the pump-sending overpressure surges to the suction side or to the atmosphere (ground) depending on brand and model. Discharge relief valves are operator adjustable with a pilot valve (handwheel).

    An intake relief valve only operates to protect the intake/suction side of the pump and is a preset valve that opens at or above whatever pressure you set it for. It is manually set using a bolt/set screw. These are typically set for 150-180 PSI depending on your desires and pressure rating of supply hose you use. Ours are set to 160 PSI. The intake relief valve in question looks like the photo in the link. (Akron #59)

    http://www.akronbrass.com/uploadedFi...fly_Relief.pdf

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    As has been stated, an Intake Relief Valve (IRV) is an NFPA required component designed to relieve excess pressure from the intake side of the pump. Current NFPA standards require an IRV to the exterior of any 3" or larger intake valve, and if you have any 3" or larger non-valved intakes you must also have one on the intake manifold of the pump (NFPA 1901, page 1901-52, sections 16.6.6 and 16.6.7). This means you could have as many as three or four IRVs depending on how your apparatus is set up.

    The true purposes of the IRV are to reduce the likelihood of a burst suction line due to water hammer and to create a pressure differential between intake and discharge pressures. This is because discharge pressure control systems (Discharge Relief Valves and Electronic Pressure Governors) cannot lower your discharge pressure any lower than the intake pressure, and in most cases only down to about 20 psi or so above your intake pressure.

    In general your IRV should be set to about 5-10 psi above your average hydrant pressure. Common settings for these systems are in the 80-125 psi range. Setting an IRV at high pressures (especially any pressure that is above your discharge pressure) defeats the purpose of the system and is not recommended.

    Some systems are set using a pilot valve, others are set by adjusting an external nut that increases or decreases tension on a spring-loaded piston. Pilot operated systems are easily adjusted by the engineer while non-piloted valves will require tools to change the pressure setting. Regardless of the control mechanism the valve should be tested and exercised on a monthly basis as part of operational checks on the pump and related equipment. Failure to perform this maintenance is likely to lead to water leaks and/or vacuum leaks from the IRV.

    Here is the recommended maintenance procedure for the Waterous system:

    1. Clean the pilot valve strainer once per month, or as needed. Remove
    the screen using a 24MM wrench. Clean and reinstall.

    2. Remove the throttle screw from the pilot valve once per month and
    clean it. If the bore is plugged, it can be flushed out with water.

    3. Test the intake relief valve system once a month with a pressurized
    water source capable of supplying continuous flow at 50 to 100 psi.
    a) Set the pilot valve slightly above the source pressure and apply
    this pressure to the pump intake. Relief valve should remain closed.
    b) Reduce pilot valve setting to slightly below source pressure. Relief
    valve should open, ‘‘dumping’’ a large volume of water.
    c) Reset pilot valve above source pressure. Relief valve should
    close.
    4. Perform pump dry vacuum test each month.
    a) Close discharge and drain valves and similar openings.
    b) Operate priming device to create a vacuum of about 22 in. Hg in
    pump, then stop primer and engine.
    c) Watch pressure gauge, if vacuum drops more than 10 in. Hg in 10
    minutes, listen for air leaks at the main valve outlet and pilot valve
    drain port and drain nipples.

    Probably way more info than you wanted to know, but it's never bad to have more knowledge.
    Just a guy...

    Lieutenant - Woodbury, MN FD (Retired)
    Road Captain - Red Knights MC, MN4

    Disclaimer: The facts and opinions expressed above are mine, and mine alone, and are not intended to represent the views of any company I have ever worked for, past or present.

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    Quote Originally Posted by Johngagemn View Post
    As has been stated, an Intake Relief Valve (IRV) is an NFPA required component designed to relieve excess pressure from the intake side of the pump. Current NFPA standards require an IRV to the exterior of any 3" or larger intake valve, and if you have any 3" or larger non-valved intakes you must also have one on the intake manifold of the pump (NFPA 1901, page 1901-52, sections 16.6.6 and 16.6.7). This means you could have as many as three or four IRVs depending on how your apparatus is set up.

    The true purposes of the IRV are to reduce the likelihood of a burst suction line due to water hammer and to create a pressure differential between intake and discharge pressures. This is because discharge pressure control systems (Discharge Relief Valves and Electronic Pressure Governors) cannot lower your discharge pressure any lower than the intake pressure, and in most cases only down to about 20 psi or so above your intake pressure.

    In general your IRV should be set to about 5-10 psi above your average hydrant pressure. Common settings for these systems are in the 80-125 psi range. Setting an IRV at high pressures (especially any pressure that is above your discharge pressure) defeats the purpose of the system and is not recommended.

    Some systems are set using a pilot valve, others are set by adjusting an external nut that increases or decreases tension on a spring-loaded piston. Pilot operated systems are easily adjusted by the engineer while non-piloted valves will require tools to change the pressure setting. Regardless of the control mechanism the valve should be tested and exercised on a monthly basis as part of operational checks on the pump and related equipment. Failure to perform this maintenance is likely to lead to water leaks and/or vacuum leaks from the IRV.

    Here is the recommended maintenance procedure for the Waterous system:

    1. Clean the pilot valve strainer once per month, or as needed. Remove
    the screen using a 24MM wrench. Clean and reinstall.

    2. Remove the throttle screw from the pilot valve once per month and
    clean it. If the bore is plugged, it can be flushed out with water.

    3. Test the intake relief valve system once a month with a pressurized
    water source capable of supplying continuous flow at 50 to 100 psi.
    a) Set the pilot valve slightly above the source pressure and apply
    this pressure to the pump intake. Relief valve should remain closed.
    b) Reduce pilot valve setting to slightly below source pressure. Relief
    valve should open, ‘‘dumping’’ a large volume of water.
    c) Reset pilot valve above source pressure. Relief valve should
    close.
    4. Perform pump dry vacuum test each month.
    a) Close discharge and drain valves and similar openings.
    b) Operate priming device to create a vacuum of about 22 in. Hg in
    pump, then stop primer and engine.
    c) Watch pressure gauge, if vacuum drops more than 10 in. Hg in 10
    minutes, listen for air leaks at the main valve outlet and pilot valve
    drain port and drain nipples.

    Probably way more info than you wanted to know, but it's never bad to have more knowledge.

    Actually, it's exactly what I want to know. Keep it coming!
    We do not rise to the occasion. We fall back to our level of training.

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    John. A question for clarification.

    The pumper has two, 2 1/2" inlets and a 6" steamer ( Hard suction) connection. If no valve is attached to the steamer connection, you require a IRV on the manifold?

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    Quote Originally Posted by GPM1230 View Post
    John. A question for clarification.

    The pumper has two, 2 1/2" inlets and a 6" steamer ( Hard suction) connection. If no valve is attached to the steamer connection, you require a IRV on the manifold?
    Yes. Every rated pump must have an IRV. If none of your inlets are valved then only a single IRV is required. If you were to add a valve to your 6" inlet then the IRV would need to be external to the valve, and you would not be required to have one on the intake manifold (though it would still be a good idea to have one).
    Just a guy...

    Lieutenant - Woodbury, MN FD (Retired)
    Road Captain - Red Knights MC, MN4

    Disclaimer: The facts and opinions expressed above are mine, and mine alone, and are not intended to represent the views of any company I have ever worked for, past or present.

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    One error in my above post, the IRV standard is actually on page 1901-53. That's what I get for quoting from memory, LOL.
    Just a guy...

    Lieutenant - Woodbury, MN FD (Retired)
    Road Captain - Red Knights MC, MN4

    Disclaimer: The facts and opinions expressed above are mine, and mine alone, and are not intended to represent the views of any company I have ever worked for, past or present.

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    @ Johngagemn,

    I'm looking for the correct IRV replacement part for a Waterous Model CSUC10C pump mounted on a 2009 pumper engine. (Serial# 131059, Prod# TID9200)

    The one that was on it is missing about an inch worth of rubber/viton sealing material, and is leaking when stationary, and sucking in air when in pump mode, creating cavitation issues.

    I don't order parts directly, but through our parts guys (another issue), and they said that I would be getting an Elkhart brass one, made of brass. What concerns me, is the one originally installed, is cone shaped, and made of aluminum. There are no markings as to who made it, etc.

    Am I going to have an issue with this, or do I need to look further, to get the same exact replacement part???

    FM1
    I'm the one Fire and Rescue calls, when they need to be Rescued.

    Quote Originally Posted by EastKyFF
    "Firemens gets antsies. Theys wants to goes to fires. Sometimeses they haves to waits."

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    Quote Originally Posted by FIREMECH1 View Post
    @ Johngagemn,

    I'm looking for the correct IRV replacement part for a Waterous Model CSUC10C pump mounted on a 2009 pumper engine. (Serial# 131059, Prod# TID9200)

    The one that was on it is missing about an inch worth of rubber/viton sealing material, and is leaking when stationary, and sucking in air when in pump mode, creating cavitation issues.

    I don't order parts directly, but through our parts guys (another issue), and they said that I would be getting an Elkhart brass one, made of brass. What concerns me, is the one originally installed, is cone shaped, and made of aluminum. There are no markings as to who made it, etc.

    Am I going to have an issue with this, or do I need to look further, to get the same exact replacement part???

    FM1
    I pulled the pump file and it doesn't look like we provided the IRV on this unit. Sounds like you believe it to be an Elkhart valve, which would have been supplied by the truck builder. Are you replacing the entire valve or just getting repair parts for it? If it's just a torn seal you could check with Elkhart to see if they have a repair kit available for it rather than replacing the whole valve.

    The Elkhart #40 relief valve is pictured here: http://www.elkhartbrass.com/files/aa...g-f2-07-27.pdf

    Worst case scenario I would call your Elkhart rep directly, here is the rep for your area I found listed on their website:

    Leanne Hankins
    Customer Service Representative
    lhankins -at- elkhartbrass -dot- com
    800-346-0250 Ext. 272

    <Edit> Edit to say that I'm guessing the Elk-o Lite version is an aluminum or alloy body with a stainless mechanism to drop both the weight and the cost down. If you are getting an all new valve in solid bronze that probably is not a bad thing. :-)
    Last edited by Johngagemn; 07-23-2010 at 03:47 PM.
    Just a guy...

    Lieutenant - Woodbury, MN FD (Retired)
    Road Captain - Red Knights MC, MN4

    Disclaimer: The facts and opinions expressed above are mine, and mine alone, and are not intended to represent the views of any company I have ever worked for, past or present.

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    Thanks for the reply.

    The part isn't an Elkhart #40, or a Elk-o Lite version. Since Waterous didn't install it, I am going to have to go to Toyne, and see what it is, they installed, and go from there.

    Thanks again.

    FM1
    I'm the one Fire and Rescue calls, when they need to be Rescued.

    Quote Originally Posted by EastKyFF
    "Firemens gets antsies. Theys wants to goes to fires. Sometimeses they haves to waits."

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    GPM1230: Lots of engines idle at a pump pressure of 60 to 80 psi. Lets run a typical two engine relay using this sort of engine along with 5” LDH with 1500 ft between engines, an automatic nozzle on an Akron master stream device fed by 200 ft of 5”, a gated wye and two 25 ft. joints of 3” to the base of the gun. Attack engine is pumping at 158 psi delivering about 1,200 gpm through the automatic. 100 psi NP; 20 psi gun loss; 9 psi in the 25 ft (at 600 gpm per line) ; Wye loss 10 psi; 9.6 psi per joint of 5” hose
    The attack engine is seeing an incoming compound gauge pressure of 20 psi, so the net pump pressure is 138 psi and well within the capability of a 1250 gpm rated engine. Supply engine is working from a fairly good hydrant that had a static pressure of 80 psi when the operator first charged the line from the hydrant. At this time, he is discharging at 164 psi and has 20 psi incoming from the hydrant. This engine is working at a net pump pressure of 144 psi and is also a 1250 gpm pump within the capability of the engine and pump.
    Now lets say that the firefighter operating the master stream needs to readjust the nozzle position requiring shutting down the master stream to reposition. Properly shutting off the gated wye simply should mean closing the valves, slowly and making the adjustment. The engine’s electronic pressure governor will throttle down to idle, but will this be enough for the safety of firefighters on the fireground.
    Without a relay relief valve we will get 80 psi hydrant pressure added to 70 psi (60 to 80) relay engine idle pressure, plus the 70 psi of idle pressure supplied by the attack engine. The 5” supply feeding the gated wye will be seeing 220 psi with both engines at idle. This is a dangerous condition because most LDH supply line is only rated at 200 psi max.
    With a 100 psi relief valve on the attack engine, the max discharge will be about 170 psi with relief dumping about 800 gpm onto the street. It will be a safe operation and prevent any blown LDH in the relay.
    These numbers will be slightly different if you use numbers from Angus published data, but the static pressures will be the same, with slightly different flows.
    I used a K of 1/15th to do the calculations for the 5"ldh.

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