Cameron BARTON 289A - Inspection and Cleaning Procedure

A-19
Model 199 Differential Pressure Unit (DPU) Section 4
Inspection and Cleaning Procedure
Instruments used in services where solids or semi-solids may accumulate
inside the pressure housings require periodic inspection and cleaning, as fol-
lows.
1. Remove the DPU from service and remove the pressure housings.
2. Carefully remove the pressure housings from the bellows unit assembly.
IMPORTANT: If accumulation of solids or semi-solids is extensive, rapid removal of the
pressure housings can damage the bellows.
3. Remove the accumulation from between the bellows convolutions and
from the inside of the housings. Use a solvent if possible. Do not use a
sharp instrument to clean between convolutions.
4. Look for broken range springs and replace as necessary.
5. Replace the housings and seals.
6. Install NEW pressure housing bolts and torque in accordance with Table
4.2.
WARNING: Do not reuse housing bolts. Reuse of housing bolts, espe-
ciallyincriticalapplicationslikehydrogensuldeandsaltwaterexpo-
sures, can result in severe injury, death or substantial property damage
due to bolt failure.
Table 4.2—Standard Bolt Torque Ratings
SWP
Housing
Mat'l
Bolt
Mat'l
Size Qty Part No.
Lube
(Note 1)
Torque (lb/ft)
(Note 2)
Rotation
(Note 3)
1000
Stainless
Steel
Steel 3/8-16 x 4.5 12 9A-C0199-1345C Yes 40 270°
3000
Stainless
Steel
Steel
1/2-13 x 5.5 12 9A-C0199-0085C Yes 80 180°
NOTES:
1. Lubricants: Molykote G paste, Teon-base pipe dope, graphite-base grease, or similar lubri-
cants. Lube rst 2 threads only. Do not lube bearing surface.
2. Torque on bolts is accomplished in 3 or 4 steps. Tighten UNIFORMLY.
3. Rotation of bolt head is measured after bolt is "snug," with approximately 5 lb/ft torque. DO NOT
EXCEED THIS ROTATION. To tighten bolts without torque wrench, use rotation values.