Ssv 8500 And 8600 Description And Resetting - Dresser Rb 4700 Inbetriebnahmeanleitung

SSV 8500
(for RB 4700 models with integrated SSV 8500)
Operating principle of the shut-off valve
The shut-off device is a safety device that goes off when
the pressure value in the downstream pipe increases or
decreases beyond the prefixed calibration values, cut-
ting automatically the flow of the gas
Shut-off valve with screw reset
These device consists of a valve body 10, a control head,
a diaphragm assembly 4 - 15 and a stem –valve plug as-
sembly 12 – 18, which remain in a balanced position
through a mechanical ball system The shut-off valve is
triggered when the pressure value in the control cham-
ber 5, that from the downstream pipe flow into this
30
chamber through the impulse intake 14, increases or
decreases beyond the established pressure values, thus
moving from its balancing position the diaphragm as-
sembly 4 – 15 The stem 18 connected to the valve plug
12 triggers under the force of the spring 13, coming im-
mediately into contact with the valve 8 cutting auto-
matically the flow of the gas
NOTE: The schematic section refers to a safety valve in-
stalled of series 8500, but the operating principle is valid
even for other safety valves installed of series 8200 and
8300
Item Description
1 Screwing ring
2 Cover
3 Vent
4 Diaphragm
5 Motorisation chamber
6 Flange
7 Valve plug plate
8 Valve orifice
9 inlet chamber
10 Valve body
11 Outlet chamber
12 Valve plug
13 Valve plug spring
14 Diaphragm plate
15 Impulse intake
16 Balls
17 Max calibration spring
18 Stem
19 Cover
20 Screwing ring
21 Min calibration spring