1. #1
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    Question Max pressure on hard suction hose

    I've got an issue with air leaks while drafting and I'm thinking our hard suction could be leaking or not sealing at the couplings. I seem to remember some one saying you could put 20 psi on a hard suction without damage, but now I can't confirm that online. Has anyone heard of this? I'm thinking of just hooking it up to the piston intake and using the head pressure from the tank which might give me enough psi water pressure to spot leaks.
    ...at this time.

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    you might be close

    http://nafhc.com/products/industrial...rd-hd%E2%84%A2


    but putting tank or hydrant pressure on it looks like it can take double
    Last edited by fire49; 02-15-2014 at 12:07 PM.

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    Good link. That looks like a pressed on coupling, which is probably more secure than what we use. I just looked at my hose and it's manufactured by KOCHEK and has clamped on couplings.
    https://docs.google.com/document/pub...2EiPsplI6J8cEk
    ...at this time.

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    If you have access to 1962

    You might see what that says about testing


    http://www.nfpa.org/codes-and-standa...code&code=1962

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    Double check all of your valves on the pump panel. We tend to have a hell of a time getting a draft started with one of our pumpers. Once we get it, it's great, but it takes a while and a lot of priming to do it. We aren't yet entirely sure, but the valve for the deck gun may be leaking slightly and causing issues. Discovered it at the end of the fall and with winter fully set in haven't wanted to mess with it more yet.

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    Be VERY careful about putting any pressure on the newer lightweight translucent hard suction hose. It is designed for negative pressure only and may burst if too much pressure is applied to it. I have seen it happen in a training session during a Dual Pumping operation.
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    ^ What Don said. ANY pressure on the new lightweight hard sleeves is bad karma.
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    Saran plastic wrap around each connection, one by one. If you find the suction working better, you found the leaking one.
    "This thread is being closed as it is off-topic and not related to the fire industry." - Isn't that what the Off Duty forum was for?

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    You can put pressure on the new lightweight suction hose once. Then you have to go find the couplings.

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    Have you done a vacuum test on the pump without the hard suction hooked up? Your problem amy be a valve or cap leaking elsewere on the pump. What type of couplings does your hard suction have? There are two different types of gaskets for Storz. One is a gasket that must be used for drafting. The other is used for pressure lines and is a bit thinner. It leaks when a vacuum is applied.

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    The original type of Hard Sleeve that is smooth with black rubber layed-up construction is supposed to be tested annually at 200 psi. Cord Flex with the raised helix was the next type of more bendable hard sleeve, and it too was supposed to be capable of the 200 psi annual test. The present light weight (some of it see-through) suction sleeve, is just that... suction only. Testing a joint of hard sleeve by pressurizing, might NOT indicate a leak because the inner lining can be forced tight into a defect, effectively sealing the leak, while that same defect will allow air to enter the sleeve at a rapid rate preventing a good prime and even breaking the prime if the flow is stopped for any period of time. As suggested by Rayr49... Perform a vacuum test on your pump first. I suggest using the suction caps that came with your engine as originally delivered. Drain the pump completely, cap off all inlets (plugs) and discharges (caps), and make sure there is water in your tank. Spend $20.00 or so on a decent vacuum gauge that has at least 2" per increment & attach it to the test plug on the pump panel. Lastly... Operate the primer until you reach at least 20 inches of vacuum (should happen in 30 to 45 seconds). A fairly tight pump will only loose about 1 inch of vacuum per minute. So you should still be near 10 inches after 10 minutes. Break the vacuum & open one of the suction caps to check for water. If your tank-to-pump or the tank fill valve is leaking, you will find a significant amount of water in the pump. If the test has shown poor results, you must then search for the cause. One of the ways is to use your ears, after operating the primer and shutting the engine down. Crawl under the rig (have the wheels chocked for safety) and listen for any leak or leaks. If the pump is tight, then remove the cap from the steamer intake, attach ONE section of hard sleeve, and place the cap over the end. Operate the primer to the 20 inch vacuum, and shut down the engine again. You will be able to hear any major leaks, but might have difficulty in determining exactly where the air is entering the suction hose. Sometimes a squirt bottle of water can help by quieting the leak if you squirt the right spot. Bone's suggestion to use saran wrap will help to pinpoint the connection. Many times helpers do not get the connections tight enough on the first attempt. If this happens, the gasket can be pulled inward when the primer is operated. If you now tighten the connection, the gasket is trapped, while partially sucked into the waterway. As soon as you loosten up the connection the gasket snaps back into the correct position, so when you look, it appears NOT to have been the problem. Keep your swivel bearings clean and replace old gaskets on a regular basis. Tighten connections well before starting to prime. For those attempting to use "Storz" fittings on suction... Regular Storz is designed to seal with internal hose pressure, and the use of regular Storz fittings is to be avoided on suction hose. There are Storz fittings that are designed for suction hose, but they have 3 lugs and a raised "bump" on the gasket material itself. Good luck in your search for the cause of the poor prime.

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