MUELLER
®
Shur Stop
TM
Unit 68 PE Line Stopping System
Operating Instructions
10
11
33. Perform the same operations on
the second fitting and install the by-
pass between the two machines.
Equalize the pressure (
O.
) of the first
slide gate valve. For this operation
rotate the knob that controls
equalizing valve counter-clockwise
until it stops.
34. Open the slide gate valve.
35. Open the machine by-pass.
36. Open the machine by-pass
located on the second stopping
machine.
37. Purge the air in the by-pass
through the drain valve located on
the downstream stopping machine.
38. Open the second slide gate
valve without acting on the internal
pressure equalizer, as pressure is
already equal above and below the
gate.
39. Ensure the proper operation of
the by-pass and check for leaks.
Q.
No. 1
No. 2
O.
Pin
Equalization Valve
Counter
Clockwise
CAUTIoN: The plug should
never be inserted and expanded
on the upstream side.
41. Turn the ratchet handle
clockwise and gradually expand the
sealing ring of the stopper. During
this operation slide the rod from top
to bottom and vice versa to properly
position the stopper in the pipe (
P.
).
42. Expand the sealing ring to obtain
a positive shut-off. DO NOT over-
tighten.
CAUTIoN: The torque applied
to the ratchet spanner should not
exceed 48 ft-lb for the 6ʺ plug.
The torque applied to the ratchet
spanner should not exceed 52 ft-lb
for the 8ʺ plug.
43. If leakage occurs between the
stopper bar and the sealing disk
gradually tighten the Allen screws.
44. Repeat the same operations on
the second stopper machine.
45. Purge remaining gas through
No. 1 and No. 2 (
Q.
).
46. Tighten the safety ring.
40. Leaving the safety ring loose,
lower the stopper and position the
long handle between the pins on
the saftey ring. If this is difficult,
repeat previous step. If necessary,
add stopping bar weights to top of
stopping machine in order to assist
lower stopper into pipe. Take care to
ensure the plug is at a 90° position
with respect to the pipe axis. Once
the hole has been passed, place the
plug in the downstream direction.
P.
Long Handle
Short
Handle
!
!
