Richter GU/F Series Overflow Valves - Manual (Page 15)

Series GU/F
Page 15
9530-070-en Revision 00
TM 6908 Edition 10/2007
Undo the hex. socket screws 914/1. Centre the
spring bonnet 513 with internals on the body 100.
Ensure that there is metallic contact between the
body and the spring bonnet. Then tighten the
screws 901/1, 936/1, 936/2 and 920/2.
Tighten the hex. socket screws 914/1 for the
bellows seal evenly in line with the tightening
torques in Section 1.3.
Undo stem nut 534.
Remove distance sleeve.
Screw stem nut 534 onto the stem 802 up to the
marking. Then counter with the self-locking hex.
nut 929/1.
Screw on lifting cap 535 and mount lifting lever 238
with locking plate 539.
9.6.5 Installation of the thrust ring
Make sure that the O-ring 400/1 is positioned
completely inside the groove of the pressure ring 124
so that it is not damaged when the thrust ring is
inserted into the thrust flange 117.
If the O-ring 400/1 has been damaged by improper
assembly, water may enter from outside into the valve
mechanism and the bellows and cause corrosion
damage. A defective O-ring must be replaced before
the valve is installed in the plant.
9.7 Tests
Following the assembly of the valve, the lift and the
test pressure must be checked.
9.7.1 Lift
Lift check:
Remove the cap nut 927/1 from the lifting cap 535
and determine the height of the stem 802 up to the
upper edge of the lifting cap 535.
Determine this measurement in both the closed
and fully opened state.
Actuate the lifting lever 238 until the mechanical
travel stop can be felt.
The measurement can be made with a slide calliper
gauge and a depth indicator to DIN 862.
The lift is derived from the difference in the two
heights. It must be at least as high as the lift given in
the test certificate.
9.7.2 Test pressure
This test should take place on a test bench
with a neutral medium such as air or water.
Regarding their suitability and precision, the
employed pressure gauges must conform to the
requirements of current national regulations (in
Germany: e.g. VdTÜV data sheet "Overflow valve
100" of the Association of the German Technical
Supervisory Boards).
All pressure tests should be carried out in
compliance with DIN EN 12266-1 or API 527.
It is recommended to use a bubble test with a 5
mm diameter hose positioned 50 mm below the
surface of water. The other end of the hose is
sealed to the outlet of the valve by means of a
plug.
To check the test pressure, the pressure in the
valve inlet is slowly increased until the valve
commences to open.
To check the reseating pressure, the pressure in
the valve inlet is slowly decreased until the valve is
bubble-tight.