Installation Guidelines for Seawater Pumps

When choosing the proper model Seawater Pump, primary consideration should be given to the BTU capacity of the condensing units(s) and available power supply.
All centrifugal pumps must be located as far below the water line, ans as close to the center line as possible. This prevents exposure above the water line when the vessel is on the plane or operating in heavy seas. Install the pump as close as possible to the seawater strainer and thru-hull fitting. Mount the oumo securely in a horizontal position with the discharge higher than the intake. Rotate pump heads towards the direction of water flow as long as the outlet remains above the inlet. All of the above helps to prevent any air locks that can cause the pump to cease proper operation and cause damage to the components.

The entire seawter system shiuld be plumbed on a continous uphill incline from the thru-hul intake to the condenser coil inlet.

Locate the overboard discharge above the water line a nd connect it to the condenser coil outlet. The unit condenser soil should be high point point of the application, if possible, thus eliminating a place to trap air and maintaining a self-purging system.

The thru-hull fitting shiuld have a clam shell type scoop, facing forward, to help maintain a constant water flow to the pump. The thru-hull fitting and seawter strainer must be equal in size to the intake opening of the pump. Restriction of flow capacity to the pump intake can result in damage to the pump components.
The thru-hull fittings should be dedicated to the system and not shared with other components or systems. The seawater strainer should be of adequate size and should be located in an accessible area for maintainance (cleaning).

A shut-off valve (ball-type is recommended) must be installed at the thru-hull fittin to provide a means to service any component below the water line.

All seawater components should be assembled using porperly sized flexible reinforced hose to provide vibration isolation. All fittings must be full-flow fittngs. Securely fasten each hose run, making sure no kinks or loops exist. Avoid or minimize 90° elbow fittings to ensure maximum water flow. All hose connections must be doule-clamped, reversing the clamps, above the water line as well as below it.

When installing multiple units, a single pump is recommended. Size the pump to the equivalent foot of head and the total BTU load of all units combined. The discharge of the pump is to be connected to a spud manifold for proper ditribution of water flow to each individual unti. This manifold should be at leaast 18" - 24" above the pump outlet. For independent control of the seawater pump from each unit, use a pump relay panel.