High Feed Pressure on Spectra Systems

High feed pressure on Spectra systems can be from environmental factors like cold water or high salinity. The feed pressure could also be high because of issues with the installation. Both the brine discharge and the product tubing should be vented to the atmosphere. That is, they should not be routed into parts of the boat that can generate back-pressure. Watching the feed pressure when these lines are both running freely into a bucket is an easy way to rule this out. Internal factors that can cause an increase in feed pressure would be a mechanical restriction in the Pressure Vessel Assembly, that is in the Membrane and/or Clark Pump.

On Spectra systems membrane scaling is rare because of system design (self-regulating pressure.) Other watermakers, where the pressure can be raised to increase output/quality, see membrane scaling frequently and often consider membranes a consumable item. Mineral scaling can occur on a Spectra when a system is running from a well, in brackish environments, or in an area with increased run-off. The remedy for mineral scaling is an SC-3 Cleaning.

An example of a restriction in the Clark Pump would be extra friction on a piston moving back and forth in a damaged cylinder. Another example would be a reversing valve spool that is moving through annular rings that have a gouge in them from an external piece of contaminate. We have also seen high pressure on older systems that have hardened O-rings (pilot spool O-rings). Most of these situations are caused from misuse or lack of service. There are dozens of internal parts in the Clark Pump that move back and forth as the Clark Pump cycles, friction in any of these parts can cause an increase in feed pressure.

Static Pressure is the feed pressure when the system is running with the Pressure Relief Valve open. This can be used to diagnose a restriction in the Pressure Vessel assembly. Your user manual should have the spec static pressure for you to reference.