JOWA F-2

Re-hardening filter for desalinated water

The JOWA F-2 re-hardening filter removes solid particles from evaporator water and raises its pH to 7.0–8.5 to limit corrosion of pipes, heat exchangers and tanks. A stainless steel (AISI 316L) vessel is filled with filter sand and pH-adjusting material between top and bottom strainers; two three-way valves switch between service and back-flushing. The manual covers installation between evaporator and fresh water tanks, filling, start-up, back-flushing, shut-off, safety, spare parts for all sizes and the type approval.

Click a part on the model to see its number and purpose.Open the 3D manual

Maintenance procedures

Back-flushing the filter

1. Turn both three-way valve handles upwards to reverse the flow. p. 5
2. Flush for about 10 minutes or until fairly clear water comes out of the flushing outlet. p. 5
3. Turn both handles back downwards for service. p. 5

First filling and start-up

1. Fill sand through the upper manhole to about 10 cm above the bottom strainer, then pH material to about 15 cm below the top strainer. p. 3
2. Fill with water through the inlet and back-flush until clear water comes out of the outlet. p. 5
3. Set both handles downwards; the filter is in service. p. 5

Maintenance intervals

Item	When	Action	Manual
Back-flushing	once or twice a week depending on contamination	Flush about 10 minutes until clear	p. 5
pH value	regularly	Check pH; top up pH material through the upper manhole as it is consumed	p. 5

Technical specifications

pH after filter	7.0–8.5 (approval: 6.5–8.5)	p. 3
Vessel material	stainless steel SIS 2353 (AISI 316L)	p. 3
Back pressure	at least 0.2 bar to prevent self-draining	p. 3
Filling	sand about 10 cm over the bottom strainer, then pH material to about 15 cm below the top strainer	p. 3
Sizes	F-75-2, 150-2, 300-2, 500-2, 750-2, 1500-2, 2000-2	p. 26

Source: manufacturer's manual “EM-27 RE-HARDENING FILTER”, 26 pages. Page numbers refer to the original. Check against the manual on board before work.