Meriam 70H_72H High Pressure Wet Tap Accutubes with Integral 3-Valve Head and Optional RTD - Manual (Page 20)

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4.7.3.16 Assemble the insertion/retraction rods and nuts onto the probe. The
rods slip through the hole on the upper insertion bar and extend 2” out
at the top. A single nut is assembled to each side of the upper insertion
bar and tightened so that the rod is locked in place. Loosely assemble
the upper drive nut on the insertion rod up to the lower lock nut. This
is done for both rods.
4.7.3.17 Insert the probe tip into the packing gland assembly and slide it until
the probe tip contacts the insertion valve. As this is done, the
insertion/retraction rods must be guided through the proper holes on
the lower retraction bar of the packing housing. The head of the
Accutube during this procedure should be oriented so that the flow
arrow points in the direction of flow. During the initial insertion of the
probe tip into the packing housing, use care not to damage the packing
rings. Assemble the lower drive nuts with washers onto the
insertion/retraction rods. Thread the nuts upward until the washers
contact the insertion flange.
4.7.3.18 Lightly snug down the packing gland socket head cap screws just
enough to set the packing in place and remove any clearances. Turn
the hex socket head cap screws an additional 1-1/2 turns to pre-load the
packing rings. Turn the screws a small amount alternately so as to
tighten the assembly slowly and evenly from both sides.
4.7.3.19 Verify the instrument valves on the Accutube are closed.
4.7.3.20 Open the insertion valve. Verify all joints and packing is sealed tightly
as the entire assembly is now pressurized. The packing assembly can
be tightened further if required.
4.7.3.21 Insert the probe into the pipe. This is done by turning the lower drive
nut (counterclockwise when looking down at the probe) to pull the
Accutube into line. Both lower drive nuts should be turned alternately
so as to prevent uneven loading and jamming of the Accutube
assembly. Use this procedure until the probe touches the opposite side
of the pipe.
4.7.3.22 Withdraw the probe from the opposite end of the pipe wall 1/8”. This
clearance is a provision for thermal expansion.
4.7.3.23 Again inspect the packing gland assembly for leakage. If required,
tighten the packing screws an additional amount.
4.7.3.24 The Accutube is now in working condition.
4.7.4 INSTALLATION PROCEDURE – 2 3/8” DIAMETER PROBES WITH GEAR
DRIVE
Follow steps 4.7.3.1 through 4.7.3.15. Then proceed with the following steps.
4.7.4.1 Insert the probe tip into the packing gland assembly. During the initial
insertion, use care not to damage the packing rings. Slide the probe
through the packing until the probe tip contacts the inside of the
insertion valve. During this procedure the Accutube head should be
oriented so the flow arrow agrees with the flow direction within the
pipe. Raise the threaded rods by turning the crank counter clockwise
until the rods protrude through the insertion bar. Assemble threaded
rods and insertion bar with nuts.