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Level Controls - IOM 200 VACUUM BREAKER 200__IOM_RevC_0618
SEAT INSPECTION AND CLEANING PROCEDURE
1
) Remove line or tank pressure and isolate vacuum breaker. (It is recommended that the vacuum breaker be removed from the piping or
tank for the seat inspection and cleaning procedure. It is recommended that you have an Inspection Kit on hand before beginning the
procedure.)
2) Remove nuts and bolts fastening valve body to adapter body.
3) Remove valve body from adapter body.
4) Remove capscrews from spring chamber.
5) Remove spring chamber from valve body.
6) Remove jamnuts from stem. Be careful, spring is preloaded.
7) Remove spring button.
8) For vacuum breakers with single spring remove spring. For vacuum breakers with dual springs remove outer and inner springs.
9) Remove disc and stem assembly from valve body.
10) Clean gasket surfaces on valve body and adapter body.
11) Inspect the integral seat or seat ring in the valve body. The integral seat or seat ring must be clean and free from deposits, scratches, or
other damage. If deposits are present clean the seat with red (fine) crocus cloth and a general purpose degreasing solvent. Cloths or
pads containing ultra fine silicon carbide such as a Scotch-Brite Ultra Fine Hand Pad or Norton Bear-Tex Clean & Finish Pad are also suitable
for cleaning the seat. Clean the seat with a circumferential motion around its diameter not with a longitudinal motion across its length.
For vacuum breakers with an integral seat, if after polishing the seat, you can still detect deposits, scratches, or other damage with your
fingernail , then replace the vacuum breaker. For vacuum breakers with a replaceable seat ring, if after polishing the seat, you can still
detect deposits, scratches, or other damage with your fingernail, then replace the seat ring. For vacuum breakers with an integral seat,
after cleaning, a light coat of primer may be applied to protect the seat.
12) Install disc and stem assembly in valve body.
13) For vacuum breakers with single spring, install spring over stem and center spring over pilot on valve body. For vacuum breakers with
dual springs, install inner spring over stem. Install outer spring over stem and inner spring. Center outer spring over pilot on valve body.
14) Install spring button on stem. Watch orientation. Center spring(s) over pilot(s) on spring button.
15) Install jamnuts on stem. DO NOT tighten until opening force is adjusted see following page.
16) Install new gasket on adapter body.
17) Install valve body on adapter body.
18) Install bolts through holes in adapter body and valve body. Install nuts on bolts. Tighten nuts and bolts in increments in an alternating
pattern.
19) Complete steps 4 thru 10 of Opening Force Adjustment Procedure.
