Cleaning; Disposal - Honeywell BFW112 Operating And Maintenance Manual

7.2 Maintenance
Interval: every 12 months
Maintenance Report - see chapter 13
Test set-up
Mount the backflow preventer in the testing equipment. Open all the valves, to bleed the system. Close valve 3. Check that the
backflow preventer is sealed.
Valve 1
7.2.1 Inspection of check valve on input
side
1. Close valve 2
2. Wait 10 seconds and observe the differential pressure.
If it is constant, the check valve is airtight. Make a note
of the differential pressure
If the differential pressure = 0, the seal on the input side is
damaged or soiled. Follow the instructions in 7.2.3.
7.2.2 Inspection of discharge valve
1. Close valve 2
2. Close valve 1
3. Slowly open valve 3 and observe the differential
pressure. The discharge valve must respond (begin to
drop) before the differential pressure exceeds 0.14 bar.
Make a note of the differential pressure at which the
discharge valve responds (drops).
If the differential pressure is <0.14 bar at the response
moment, follow the instructions in 7.2.3.
MU0H-1264 GE23 R0818
GB
Valve 3
7.2.3 Maintenance
Note: For exploded drawing see chapter 11
1. Fix the backflow preventer on the key area of the
housing and open the cover on the output side with the
help of a tape puller
2. Remove the springs and piston
3. Clean all interior parts and the running surface with
clear water and check that they are in good condition.
4. If necessary, exchange all seals and pistons. When
dismantling, ensure that the sealing faces in the base of
the groove are not damaged.
5. Lightly grease the seals.
6. Reassemble in reverse order.
7. Carry out points 7.2.1 and 7.2.2 for inspection.
8

Cleaning

If necessary, clean the backflow preventer with clear water!
Do not use any chemicals or similar!
9

Disposal

see Chapter 4 Scope of Delivery
Observe the local requirements regarding correct
waste recycling/disposal!
5
Valve 2
Honeywell GmbH