L7 – 12
Plastic valves
11/2020
Errors and omissions excepted
Notes for correct installation
Installation and operation should be performed by qualified
personnel and in compliance with all safety regulations
(eg UVV etc.) and common technical rules.
The valve must be installed stress-free in the pipeline
(plane parallelism, axial, length). If possible, use three de-
tachable pipe connections (flange or screw connection).
Flange connection:
Connecting bolts have to be tighten evenly crosswise
(observe the tightening torques of the screws). For plastic
flanges in general washers have to be provided for bolts
and nuts.
Cement / welding socket, cement / welding spigot:
For the gluing or welding connection the relevant
guidelines (e.g. DVS) have to be noted.
Before commissioning the bolt torques on the
housing must be checked and retightened if necessary.
Assembling of the valve
The valve assembly is to be performed in reverse
order to the disassembly.
Before the assembly all parts have to be checked
for damages.
All parts have to be clean.
Screws
9
have to be mounted evenly and crosswise
according to the torques (see above).
After assembly carry out a pressure test acc. to
DIN EN 12266-1.
Disassembling the valve
Attention:
Never dismantle the valve when the pipe is
under pressure.
Put the valve in an upright position, turn off cap
8
.
Release counter nut on adjusting screw
7
and turn
the screw counterclockwise until the compression
spring
5
is completely relieved.
Loosen the connecting screw
9
on the housing and
lift off the upper part of the valve.
Remove: spring plate
6
, pressure spring
5,
thrust
piece
4
, diaphragm
3
and piston (type V 85; s.p. L7 – 12).
Maintenance manual and mounting instructions
Pressure relief valve type V 85 and type V 185
DN 15/20 25/32 40 50 65 80 100
Md
9
12 20 20 29 29 29
Tightening torque Md
for body connection in Nm
Maintenance
The valves are nearly maintenance-free.
For heavily soiled and particle-carrying media, depending
on the degree of soiling, cleaning is recommended at
appropriate intervals.
For cleaning, disassemble the valve into individual parts
(for instructions, see „Disassembling the valve“).
Depending on the operating conditions and operating
time, various components may show signs of wear.
As spare parts we recommend: diaphragm
3
,
compression spring
5
, adjusting screw
7
with nut.
Adjusting the working pressure
Remove cap
8
, loosen lock nut.
Increace working pressure:
Turn adjusting screw
7
clockwise.
Decrease working pressure:
Turn adjusting screw
7
counterclockwise.
Lock adjusting screw
7
with lock nut and mount cap
8
.
Disorder
Cause
Elimination
Leakage on the adjusting screw
Diaphragm defective
Replace diaphragm
Leakage between upper and lower part
Housing screws loose
Retighten screws acc.
table screw tightening torques
Valve does not close properly
Sealing seat is dirty or damaged
Clean sealing seat and check for damages
Trouble shooting
V 185 (DN 15 – DN 50)
