Sprinkler blowout problems


Old 10-07-13, 05:03 PM
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Sprinkler blowout problems

I'm trying to blowout sprinkler system for winter and have an issue with the Bonnet/Poppet sealing when air is pushed thru. the poppet remains open and won't close. What am I doing wrong here? I have a Febco 765DBV 3/4" Pressure Vacuum Breaker. Ball valve to house closed and valve to sprinkler system open. 1 of the small outlet closed and other open to allow air in from compressor. I turn on compressor and start pushing air thru at around 40 psi and increase with no luck. Any ideas?
Old 10-07-13, 08:22 PM
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Welcome to the forums.

I'm not entirely clear on your order of connections there but you need to put air into the system after the vacuum breaker. So there should be a shut-off valve between the vacuum breaker and where you are inserting your compressor.
Old 10-08-13, 06:57 AM
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Blowing out pipes requires volume more than pressure. A slow stream of high pressure air can bubble past the water. You want a large slug of air voluminous enough to fill the pipe so the water has to be pushed out. Large diameter connections to a large air tank at lowish pressure with a 1/4 turn ball valve works well. Connect up the tank, make sure the heads or drain plug is removed, open the valve and whoosh.
Old 10-16-13, 05:22 AM
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try this...close the out valve, put hose on lower ballcock and apply air which should seal the poppett turn ballcock off leaving pressure inside bacflo and re-hook to upper ballcock and apply air. the poppet should remain closed now so you can open down valve and zone valve. You can use the lower ballcock entirely with effective results but they tend to vibrate and damage the poppets of febco bacflo's it actually loosens the screw on the lower poppet seal.

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