SeaWaterDistiller SWD 20

Visually inspect evaporator and condenser plate bundles for scale buildup at semi-annual intervals (twice yearly). Remove man-hole and bottom covers of heat exchanger to examine tube condition and check for Neoprene coating exfoliation. Remove condenser covers to verify no fouling of cooling tubes with sludge. Perform chemical analysis of evaporator liquid for silica, calcium, and mineral content to confirm descaling need. Use chemical descaling agents (e.g., sodium polysulphate with anti-foam compounds) every 6-12 months or as needed based on salt content.

Perform leak test after maintenance or if vacuum maintenance difficulty occurs. Standard: vacuum must not fall more than 2% in 8 hours under normal operation. If vacuum drop exceeds 2% in 8 hours, inspect and seal deteriorated packings and joints immediately. Use pressure/vacuum gauges to monitor system continuously during operation. Check all joint connections, flange seals, and packing glands for visible leaks or weeping. Document baseline vacuum readings and monitor trending to detect progressive leaks.

Inspect wire mesh demister for salt encrustation, clogging, or physical damage quarterly. Clean demister using fresh water spray and verify mesh integrity (holes should be visible under backlight, no collapsed sections). Check output salinity continuously: should be 2-10 ppm adjustable set point (alarm if exceeds 4 ppm per IMO standards). If salinity exceeds threshold, demister must be cleaned immediately or replaced. Monitor vapor quality visually for excessive liquid carryover (droplet mist instead of clean vapor).

Perform hydrostatic pressure test on condenser quarterly using 1.5x normal operating pressure with fresh water to verify tube/plate integrity. Visual inspection: check condenser cooling jacket for visible salt deposits or staining indicating past leakage. Monitor distillate salinity continuously using calibrated salinometer (2-10 ppm range); if salinity rises above set point despite normal demister operation, investigate condenser for internal leaks. Replace any corroded or perforated condenser tubes/plates immediately. Test sea water cooling circuit for blockage that may cause condenser overpressure.

Perform visual external inspection annually for visible corrosion, discoloration, or surface attack on all seawater-exposed titanium and 316L stainless steel components (evaporator bundle, condenser bundle, connecting lines). Internal inspection every 3-5 years: remove plates and examine for scaling, biofouling, or micro-pitting using magnification if needed. Use non-abrasive cleaning (avoid sand blasting or steel wool) to protect titanium passivation layer. For seawater-contact areas, specify titanium or superduplex (2507) material at maintenance: avoid lower-grade stainless in salt-spray zones.