MUELLER
®
Shur Stop
TM
Unit 812 PE Line Stopping System
Operating Instructions
11
48. If leakage occurs between the
stopper bar and the sealing disk
gradually tighten the Allen screws.
49. Repeat the same operations on
the second stopper machine.
50. Purge remaining gas through No.
1 and No. 2 (
r.
).
51. Tighten the safety ring.
52. Make the repairs.
53. Before decompressing the
sealing ring, it is necessary to
equalize the pressure upstream and
downstream of the same stopper (
s.
).
When only gas comes out of the vent
No. 2, close the respective gate valve
letting the gas equalize pressure.
It is now possible to test the new
connections (
T.
).
54. Decompress the sealing ring of
the stopper by operating counter-
clockwise on the ratchet handle until
a hard stop and retract the stopper
inside the stopping machine.
55. Repeat the same operations on
the second stopping machine (
U.
).
56. Close the related slide gate
valves.
57. Bleed the gas contained in the
bypass at a suitable distance from
possible sources of ignition (
v.
).
58. Remove the bypass and the
stopping machines (
w.
).
r.
No. 1
No. 2
v.
Bleed Valve
U.
Vent Closed
No. 1
No. 2
T.
Vent Closed
No. 1
No. 2
s.
No. 1
No. 2
Hose
Vent open for Purging
w.
No. 1
No. 2
