4.3 Connecting Seawater to Heat Exchanger

Refer to Figure 23 for typical seawater plumbing arrangement.

  1. Connect seawater pump to Seakeeper dedicated through-hull fitting. A strainer and seacock valve should generally be installed between the seawater inlet and the pump.
  2. Connect seawater from installer-supplied pump to lower ¾ in. (19 mm) hose barb onheat exchanger. Use the same practices as other below waterline seawater plumbing.
  3. Connect seawater discharge (upper hose barb) to overboard drain. Use the same practices as other below waterline seawater plumbing.
  4. Required flow rate is 2 GPM (7.6 LPM) minimum and 6 GPM (22.7 LPM) maximum.
  5. In addition to initial operation at dock, new Seakeeper installations should be checked for minimum 2 GPM (7.6 LPM) flow while vessel is at speed and when backing down.
    1. If no other method of confirming flow is available, discharge line may be temporarily diverted to a bucket. Flow is calculated from time to fill a known volume.
    2. A self-priming seawater pump (customer/installer supplied) may be required due to installation location to maintain water flow in all underway conditions where cavitation near the intake may occur and potentially cause an air-lock condition restricting seawater flow to the heat exchanger.
  6. Inspect raw water plumbing after sea trial for any signs of leakage.

4.3.1 Seakeeper Optional DC Seawater Pump (P/N 30331)

  1. Seakeeper offers a self-priming DC Seawater pump as an optional addition, P/N 30331– DC Seawater Pump Assembly, shown in Figure 24.
  2. The Seakeeper Seawater Pump is a 24 VDC pump operated at 12 VDC for the Seakeeper 3 and maintains a seawater flow of approx. 2.5 GPM (9.5 LPM) at 12V DC.
  3. The pump assembly is pre-wired for connection to Seakeeper 3 Seawater Pump Output Cable and includes a seawater strainer and various fittings. The pump specifications are as follows:

NOTE: Use only SeaFlo-provided threaded fittings for DC Seawater Pump 30331.

Voltage:24 VDC (Operate at 12 V for Seakeeper 3)
Rated Flow:2.5 GPM (9.5 LPM), at 12 VDC
Overcurrent Protection:15 A
Ignition Protection:ISO 8846 or equivalent
Figure 24 – Seakeeper 3 DC Seawater Pump (30331)