Meriam 70H_72H High Pressure Wet Tap Accutubes with Integral 3-Valve Head and Optional RTD - Manual (Page 18)

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4.7.2.4 The retainer is now placed atop the follower and secured loosely in
place with the packing gland socket head cap screws. Do not tighten
the screws at this point.
4.7.2.5 Assemble the instrument valves onto the Accutube probe head.
4.7.2.6 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 closed
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.
4.7.2.7 Lightly snug 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 each 1-1/4 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.
4.7.2.8 Verify the instrument valves on the Accutube head are closed.
4.7.2.9 Open the insertion valve. Verify all joints and packing are sealed
tightly as the entire assembly is now pressurized. The packing
assembly can be tightened further if required.
4.7.2.10 Remove locking rod from crank handle.
4.7.2.11 Insert the probe into pipeline by turning the crank handle
counterclockwise to pull the Accutube probe into the line. Use this
procedure until the probe touches and stops on the opposite side of the
pipe.
4.7.2.12 Withdraw the probe from the opposite side of the pipe wall 1/16” on
12” line size and less, or 1/8” on larger line sizes. This clearance is a
provision for thermal expansion allowances and assures centering of
port holes.
4.7.2.13 Position crank handle so ¼” threaded hole is visible on lower insertion
bar. Insert locking rod.
4.7.2.14 Again inspect the packing gland assembly for leakage. If required,
tighten the packing screws an additional amount.
4.7.2.15 The Accutube is now in working condition.
4.7.3 INSTALLATION PROCEDURE - 2-3/8” DIAMETER PROBES WITH
SOCKET DRIVE
4.7.3.1 Verify that the operating pressure and temperature are within the
Accutube probe and valve limitations (see general catalog).
4.7.3.2 In determining probe installation position a vertical position either
above or below the pipe is recommended for 24” line sizes and greater
because the assembly weight extends to the side. Support of the
assembly is required for horizontal probe position on larger line sizes.