I get it now, I missed the greater than 30ft part which I now understand is the crux of the matter. Duh. The P250's were 250 Gallons per minute capacity and intended for firefighting and damage control dewatering operations with up to 20ft suction. Entirely different application. Mr. Torricelli would have been impressed with the air injecting technique and the diaphragm pump sucking water to 50ft. I remember the P250 system also had a rig to pump pressurized clean sea water into a damaged flooded compartment that had debris and operate a submerged unit using bernoulli's principle to dewater the compartment. Again a different application and a different animal.
From: [email protected] To: [email protected] Date: Tue, 25 Jan 2011 18:19:19 -0500 Subject: Re: [Liveaboard] Thanks Bob, Ben, and Norm (diaphragm pumps) Ahmet, There was no tube strapped to the suction hose. If we wanted to add an air hose we could have used a air operated pump at the bottom of the hose. The air hole in the pipe was small, perhaps a quarter inch. The pipe was perhaps 1 1/2" diameter. The diaphragm pumps "pulled" the water up in the hose and air entered the water column lightening the water so eventually the water reached the deck 50 feet above. The air injection was never zero or the water would not have risen more than 30 feet. The tanks were being cleaned by spraying hot seawater all over the insides so the tanks were essentially empty. Most of the water had already been removed using the stripping pumps. The deck gang was pumping the last bits of water from the tanks so the portable diaphragm pumps being used were not "high capacity pumps". Norm S/V Bandersnatch Lying Julington Creek FL N30 07.68 W081 38.47 ----- Original Message ----- From: ahmet erkan To: [email protected] Sent: 1/25/2011 7:49:21 AM Subject: Re: [Liveaboard] Thanks Bob, Ben, and Norm (diaphragm pumps) Speculating the air injection should be high at the start and zero after the suction hose is fully primed. A tube strapped to the suction hose might allow the priming and then it could be plugged. One could even push compressed air into the tube to super aerate the fluid and maximize the height. This should be convenient since the pump is air operated. Alternately a big check valve at the bottom might allow the suction hose to be primed with water from top? I remember the P250 centrifigual pumps required an air tight suction hose to operate at full capacity without sucking air. That brings the question; "air operated diaphragm pump"? I understand using air or water to drive the pump in a flammable environment but why use a diaphragm pump for a high capacity application? Maybe it wasn't "high" capacity? Just curious. Cheers. _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://liveaboardonline.com/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardonline.com/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
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