Conference unifix::sailing

    When I installed an accumulator in my potable water system, I needed
    to do some adapting.  I found a hardware store in Warwick RI that
    also sells marine and plumbing supplies that had everything I needed.
    The name is Salk's.
    
    I have a question for you on the planned installation. Is there
    a reason why you are going to use a Y valve and not just a Tee ?
    
    My Tartan uses the same overboard for both the automatic sump and
    manual bilge pumps. I havent had any backflow problems and there
    is no Y valve.  I know there is a anti-siphon loop and a tee. I
    will look at the installation and let you know how its put together
    if you like. It might save the expense of a Y valve on the discharge.
    
    Walt

    Walt,
    I'd appreciate it if you would describe yours. Have you any experience
    with "check valves" to stop water from flowing back. If I went with
    a tee, I would need anti-siphon or check vaves on each input,side.
    right? Ttrying to picture the layout in my head!!
    
    Thanks,
    Ed

    I wont be back to the boat untill this next weekend. I will check
    the exact layout then - I know there are no check valves on this
    system though. I think there is an anti-siphon loop on the discharge
    of both pumps, then they lead to a tee.   
    
    My last boat didnt come with a bilge pump of any kind. When I installed
    one I routed the discharge to the nearest overboard - which was
    the galley sink drain.  Unfortunately, the sink tended to be about
    even with the waterline when heeled on a port tack - the drain tap
    for the bilge pump was below.  It was at this time I discovered
    that the pump I had installed (a Rule) and most others, have no
    check valve.   I investigated the anti-siphon loop but had noplace
    nearby that allowed extending the loop above the waterline.  For this
    installation I settled on a 1" checkvalve from a local plumbing
    supply store.   I used a plastic valve designed for wells since
    the only other ones were made of brass and subject to corrosion.
    The valve stopped the backflow of water into the bilge fine and
    did not require any service for the next 3 years (sold the boat
    then) but it did cause some back pressure which almost doubled the
    time it took to pump a given amount of water from the bilge. I
    never tried an anti-siphon loop for comparison of pumping time.
    
    If this super weather holds I may sneak a visit to the boat midweek.
    
    Walt

re check valves: The safety standards of the American Boat and Yacht 
Council state that no check valves shall be used in bilge pump discharge 
lines. Most electric bilge pumps such as the Rule designs are made to 
pump large volumes of water at minimal pressure. A check valve requires 
a relatively high pressure to open, thus the increases pumping time 
noted in the last reply. Also, use the largest diameter hose you can to 
minimize the back pressure seen by the bilge pump. The GPH ratings of 
most bilge pumps are made with no hose attached to the outlet. So the 
GPH you buy isn't what you'll have in reality. Use either an anti-siphon 
loop (fairly expensive) or loop the hose as high as possible above the 
(heeled) waterline. Note that manual diaphram bilge pumps, by their 
design, have a built-in check valve -- the outlet valve of the pump. 
When PS tested manual bilge pumps some time ago, the only pump that 
actually pumped the GPH claimed by its manufacturer was the big and 
expensive Edson with 2" hose. Installing one of those is a real 
challenge.

Alan

    Here is what my installation looks like:
    
    The manual pump (mounted at seat level in the cockpit) has 2" inlet
    and outlet hose.  The outlet hose travels up to the under side of
    the combing and aft about 2'. From there it drops about 18" to a
    Tee where the sump pump connects.  From the Tee there is about 18-24"
    to the thruhull near the waterline.
    
    The automatic sump pump has 1" ID hose on the inlet and outlet (this
    pump drains a shower/ice box sump).  The pump is mounted below the
    galley sink near water level. The outlet hose travels up and aft
    to the underside of the cockpit combing and aft about 3'. It then
    drops to the Tee connection.
    
    As you can see the hoses are strung high to create their own anti
    siphon loop. As best I can tell the Tee is above the water line
    even at heel. This allows either hose to act as the vaccum breaker
    for the other (which is a characteristic of dedicated anti-siphon
    loops) to allow an air bubble in the top of the loop of a drain
    line that just pumped water and prevent siphoning backwards.
    
    Hope this helps.
    
    Walt 

     I just installed a Rule 2000 pump and float switch in the Fin bilge
     of my sailboat. It works well except that I have a problem with 
     oscillation. The pump is located in the bottom of the bilge where
     the dimensions are approximately 5" wide by 9" long. The hose
     length to waterline level is 3 ft, the length to an outlet 1.5 feet
     above waterline is 10 feet. The hose is 1.125" in diam. What happens 
     is that the pump evacuates the bilge until the float drops and the
     water is held in the hose. The pump quits and the water drains back 
     into the bilge which is small enough that the raised water level is
     enough to activate the float switch, and the cycle starts again.

     I soft installed a vented loop I had for the Head refurb I was doing
     and found the problem to be the same. The problem is that 4.5 feet of 
     1.125" hose holds 53.7 cubic inches of water, and the small size of
     the bilge at the bottom, this translates to a level of 1.5" (enough
     to activate the switch). so no wonder a vented loop didn't work. The 
     following picture illustrates the system;

---------------------------------------------------------+
                                                          \
                                                    HHHHHHHO------>
                                         HHHHHHHHHHH        \
                              HHHHHHHHHHH___________------__/
_____________________________H__---------           ___--- 
\                          /H                      /   
 \                         H ___--------      |   |       Where
  \-------------+         H /           \     |   |        P --> Pump
   \             \       H /             \    |   |        F --> Float Switch
    \             \     H |               \   |   |        H --> Hose
     \  Ballast    \   H  |                \  |   |        O --> Thru Hull
      \             \ H   |                 +------
       \             |P-F |
        +-----------------+

     I see that are possibly two solutions;

        a) Move the switch higher up in the bilge where the space is larger
           and hence the 54 cu in of water backflow won't be enough to 
           activate the switch. This means that I carry more water in the 
           bilge.
        b) Install a check valve to prevent the backflow of water, which
           reduces the flow.

     Is it possible to get a low pressure, non leaking check valve of 
     diameter 1.125" or 1.25" ?

     Anybody have a better idea ?

     /jim     

    I installed a check valve in a 25" several years ago (see .3) but
    Alan Berens correctly cautions against its use. Although it never
    happened to me it could easily foul open or closed. Either way could
    be a problem.
    
    My suggestion is to raise the switch a bit, and put a 3-way control
    switch in to allow you to completely evacuate the bilge under your
    control.  A 3-way switch has Automatic-Off-Manual positions. I think
    Rule makes one for this.  If your handy you can do it yourself easily
    enough with the Rule switch or with one that matches your other
    power controls.
    
    Walt

    Note that an anti-siphon loop is not anti-siphon unless it is vented.
    The schemes that have been described above, in which discharge tubing
    rises, then falls again, with no vent, will happily siphon water
    back into the boat under the right (wrong) circumstances.
    
    John