NuFlo Barton 202E - DPU Replacement; DPU Cleaning and Inspection; Pressure Check Procedure

8°
Torque
Tube
Shaft
DPU Replacement
Before installing a replacement DPU, the new DPU should
be checked for proper torque tube rotation:
1. Mount the DPU on a suitable pipe stand and connect to
 a standard pressure source.
2. Adapt a graduated degree scale to torque tube housing.
3. Adapt a pointer to exposed end of the torque shaft.
4. Apply 100 percent differential pressure to the high-
 pressure housing of the DPU. The pointer attached to
 the torque tube shaft should indicate 8 degrees of travel.
B. Cleaning/Inspection Procedure
 Instruments used where solids or semi-solids may accumulate inside the
 pressure housings require periodic inspection and cleaning, as follows.
 1. Remove the DPU from service and remove the pressure housings.
 2. Carefully remove the pressure housings from the bellows unit assembly.
 This procedure should be performed prior to removing the DPU housing
 bolts, if the DPU has been installed in gas applications with working
 pressures greater than 200 psig.
 1. Back off all housing bolts 4 turns.
 2. Check for internal pressure by attempting to move the housing in and
  out along the bolts.
  a. If the housing moves freely – no pressure is present – servicing
   or repair may continue.
  b. If the housing does not move freely – the bellows may be pressurized
   and is potentially hazardous if further disassembled.
   Tighten the bolts and return the unit to the factory or authorized
   NuFlo service center for repair.
   Tag the unit and specify “Gas in Bellows”.
Notice – If accumulation of solids or semi-solids is extensive, remove the
housings carefully to prevent damaging the bellows.
A. Pressure Check Procedure
DPU Cleaning and Inspection
WARNING
(HIGH-PRESSURE GAS INSTALLATIONS AND PRESSURES
GREATER THAN 200 PSIG)
HIGH-PRESSURE GAS HAZARD ON DISASSEMBLY OF THE DPU.
BEFORE REMOVING THE DPU HOUSING BOLTS, PERFORM THE
PRESSURE CHECK PROCEDURE (See STEP “A” below).
WARNING
FAILURE TO PERFORM THIS PROCEDURE CAN RESULT IN
SEVERE INJURY, DEATH OR SUBSTANTIAL PROPERTY DAMAGE
DUE TO THE RELEASE OF INTERNAL PRESSURE.
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