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07-28-2012
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#1
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Calgary, Alberta
Join Date: May 2009
Posts: 141
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Pressure relief valve question.
Having never seen one in action before, my gut tells me a pressure relief valve should relieve pressure in bursts if your exceed a certain pressure, not slowly release air?
I've inflated my new (to me) used boat and the floor loses air slowly. I've found the location and it's coming directly from the pressure relief valve (not around it), and I'm thinking it's not working correctly.
Any tips? Do I just have to change out the valve, and if so, is this fairly simple for a novice to accomplish?
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07-28-2012
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#2
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Buenos Aires, Argentina, ...
Paddling Since: 2010
Join Date: Sep 2011
Posts: 135
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A first step might be to take the valve apart and clean it. Also, take a look at it and see if there is any aparent damage. Put it back together and if its still leaking work on getting it replaced.
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07-28-2012
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#3
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Buenos Aires, Argentina, ...
Paddling Since: 2010
Join Date: Sep 2011
Posts: 135
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You can find videos on the NRS website and on youtube the will show you how a valve is put together. Its fairly simple, just be careful with loosing parts.
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07-28-2012
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#4
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Wondervu, CO, Colorado
Paddling Since: 2001
Join Date: May 2008
Posts: 146
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It's easy for sand to get into the valve and cause slow leaks, usually I can clear it with a good blast of clean water.
If not you will need to disassemble the valve for cleaning. Some styles have replacable o-rings or other parts. If all else fails get a new valve.
Don't be tempted to just plug up the valve and go. PRV's are there to prevent floor blowouts. I blew my floor when a malfunctioning PRV failed to release excess pressure when I foolishly rigged the boat on top of some hot asphalt pavement.
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07-28-2012
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#5
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Calgary, Alberta
Join Date: May 2009
Posts: 141
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Quote:
Originally Posted by Pro Leisure
You can find videos on the NRS website and on youtube the will show you how a valve is put together. Its fairly simple, just be careful with loosing parts.
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Thanks! Good video with simple instructions.
I had the foresight to order a valve wrench so I'm good.
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07-28-2012
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#6
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leadville, Colorado
Paddling Since: 2004
Join Date: Jul 2009
Posts: 237
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So I understand the function of this valve. So question! If I forget to releave pressure in my raft, leave it on my car at heckla, run brown's. It should protect my raft? Just trying to fully understand all aspects of rafting. Knowledge is power. Thanks
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Status: Online
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07-29-2012
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#7
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Wondervu, CO, Colorado
Paddling Since: 2001
Join Date: May 2008
Posts: 146
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The PRV valve is designed to vent air when the air pressure gets too high, thus preventing a floor blowout.
Excessive air pressure could be the result many things, pumping too much air while inflating the boat, air expanding in the hot sun, changes in atmospheric pressure as a raft is transported over a mountain pass or even hitting a submerged rock.
Keep in mind that while the floor is protected by the PRV the rest of the boat is not. You could still blow your tubes or baffles if you failed to reduce air pressure when needed.
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07-29-2012
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#8
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Join Date: May 2006
Posts: 415
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Definitely clean it, PRV valves are notorious for being a general PITA and often faulty. I would say not necessarily about the bursts though even though that makes sense. Usually once you fill up the floor it will sputter and gurgle for how ever long it takes for the pressure to go down. You really don't know for a day or two if it's actually faulty if your floor goes half full. It takes quite awhile for that little valve to lose enough volume for it to close at the rate it lets air out. I would fill it, let it sit for several hours, then test it with soapy water. A few extra pumps in the floor to start though it will sputter air for quite some time before closing up.
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07-29-2012
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#9
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Stevensville, MT, the 'Root
Paddling Since: 2020
Join Date: Apr 2007
Posts: 3,340
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You could use a pressure gauge to see if it is releasing at low pressure, which indicate some repair is in order. If you are at home just replace the pos. once they leak they seem to always.
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I am a river, babe - I've got plenty of time, I don't know where I'm going, I'm just following the lines..... - "We are water" by Shaye
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07-29-2012
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#10
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Calgary, Alberta
Join Date: May 2009
Posts: 141
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Thanks for the tips.
I deflated the boat and tried to just run some 303 through the valve and manipulate the plunger in it from the bottom of the boat as per the NRS video... but the double-thick PVC on the bottom of my RMR boat was too stiff to operate the plunger. I'm going to have to take the valve out and do it manually and see if that works... but I'm away on business for a month so it will have to wait.
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