6
EN
Key
1 - Casing
2 - Outlet drain holder
3 - Hex head screw
4 - Union nut
5 - Draining valve seat
6 - Discharge valve spring
7 - Discharge valve
8 - Upstream check valve
9 - Retainer
10 - Draining valve stem
11 - Downstream check valve
12 - Membrane disc
13 - Safety seal
14 - Draining valve head
15 - Draining valve seat and cover
16 - Cover
17 - Test cock chain
18 - Protective head
19 - Eye bolt
20 - Screw
21 - Test cock M 1/2“ Gas
22 - Draining valve head seal
23 - Membrane
3. Nomenclature and sizing
In accordance with national statutory
regulations, BA backflow preventers must
be regularly inspected (once a year in most
countries) by an authorised maintenance
technician.
BA backflow preventers must undergo
compulsory annual testing using test
equipment conforming to NF P43-018,
such as Socla ref. 2234900M2 or
equivalent.
This equipment must be checked at least
once every two years.
*DN200-250
For the disman-
thing, two outlet
M10 threadings
are provided on
the seats.
DRAINING VALVE ASSEMBLY A
3.2 Fitting / removal instructions
3.1 Testing kit
All components of the backflow preventer can be checked or replaced on site without removing the entire device.
• Stop the flow by closing the upstream and downstream stop valves.
• Drain the backflow preventer by opening the upstream test cock.
• Remove the screws (20) of the cover (16).
• Separate the cover (16) from the casing (1). If necessary, in case the cover gets stuck, insert any cover screw (20) into the ad-
ditional hole of the cover until the cover is free.
• Take out the draining valve assembly A from the casing (1).
Remove the check valves:
• Remove the retainers (9) using pliers.
• Remove the 1st check valve (8) : introduce a rod on the inlet side, and gently hit the check valve. Repeat the same operation for the 2nd
check valve (9) (11).
Remove the relief valve seat:
The seat (5) of the draining valve is fitted in piston position on the bottom of the casing (1), take it out:
• By hands through the internal side of the body if possible
• By pushing in direction of the body inside through the discharge hole using a screwdriver.
