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Engine Flushing Through Sea Strainer

Discussion in 'Engines' started by Footy men, Nov 4, 2020.

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  1. NYCAP123, Feb 1, 2021
    #21
    NYCAP123

    NYCAP123 Senior Member

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    I remember that on some boats I gave lessons and orientations on back in the early 2000's. Taught the people how to use it, but can't say I've ever heard any feedback on it good or bad. Haven't heard anything about it catching on in the industry. Some boats have a fresh water flush system which IMHO is good, but even they tended to be a novelty more shown off on the dock than used after the first season.
  2. Landscaper, Feb 15, 2022
    #22
    Landscaper

    Landscaper New Member

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    Nov 24, 2020
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    Hello,

    Do you have any information about where that cap on the Guidi strainer with the threaded fitting came from?

    I do not believe it is a standard part from available from Guidi or Princess., and although Seaboard Marine sells flush caps like that for Groco strainers, I have not seen anything like that available for Guidi strainers. I would like to make a similar arrangement on my Princess 56, which has the same 3" Guidi strainer as shown in the photo, and I'm trying to determine the best way to obtain or make a cap with a fitting like that. I'm currently thinking of buying replacmenet metal caps from Guidi and having them drilled and tapped by a machine shop to accept a threaded fitting.

    Thanks for any information you have.
  3. rtrafford, Feb 15, 2022
    #23
    rtrafford

    rtrafford Senior Member

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    The principles of hydraulics sort of stumps me on this. Both dockside bibs are fed from the same delivery feed, and the transition from the Y to the single hose does not increase the volume of the hose leading to the vessel. I don't see in my mental calculations how this will enhance the water flow, nor do I see how it will increase the ability to pull more water.
    bayoubud and d_meister like this.
  4. mapism, Feb 15, 2022
    #24
    mapism

    mapism Senior Member

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    As I said in the original post, I've only used that "Y" connection in some marinas, and based on basic observation rather than any calculation.

    But in my experience, while in most dock pedestals all bibs are indeed fed by a single delivery pipe, that is much larger than the single bibs.
    So, if for instance the delivery pipe is 1", but the single bibs are 1/2", what restricts the flow is the latter, not the former.
    Which is what would happen if the all-3/4" system that I normally use (hose+strainer connection and valve) is connected to a single 1/2" bib: it can't obviously deliver the flow rate it's capable of.
    That is the situation the "Y" connection that I showed in that post is meant to address, allowing two 1/2" bibs to feed in parallel the 3/4" line.
    And I can assure you that it makes a visible difference, regardless of any calculation - that I never made, anyway.

    OTOH, coming to think of basic maths, I half recall that in construction 1/2" pipes are only used whenever the required mass flow rate is 15 liters/minute max, as opposed to the nowadays more popular 3/4" pipes, which are good for almost 40.
    So, two 1/2" connection arguably are still not as good as a 3/4" connection (30 liters vs. 40), but much better than a single 1/2" connection (15 liters only) anyway.
    I'm using liters just because that's what's I'm used to, but you see what I mean anyway.
    Last edited: Feb 15, 2022
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