Manual

IOM-DA5 11
3. Upstream pressure too high.
Possible Causes Remedies
A. Debris in trim preventing movement. A. Clean unit of debris.
B. Undersized regulator. B. Check actual fl ow conditions; resize regulator for
min i mum and maximum fl ow; if necessary, replace
with larger regulator.
4. Diaphragm continually breaks (steam service regulators).
Possible Causes Remedies
A. Stem seals, which protect fl uorocarbon elastomer in
diaphragm assembly, may have deteriorated.
A. Replace with new seals.
B. Diaphragm nut may not be torqued to proper
value.
B.
Confi rm torque value in accordance with Section VII,
paragraph E-15.
C. Diaphragm too stiff causing it to crack in service. C. Follow proper preforming and air evacuation tech-
niques during diaphragm installation in accordance
with Section VII, paragraph F-13.
5. Diaphragm continually breaks (all regulators).
Possible Causes Remedies
A. Differential pressure across diaphragm may have
exceeded limits.
A. Reference limits as recorded in technical bulletin
DA5-TB, as well as where the various pressures
are acting.
6. Leakage at diaphragm fl ange.
Possible Causes Remedies
A. Body bolts not torqued high enough. A. Torque to proper value (see Section VII, paragraph
F-14).
7. Leakage across seat or dynamic side seal.
Possible Causes Remedies
A. Contamination (debris) in regulator. A. Remove internals, clean, and if necessary, replace
regulator.
B. Oversized regulator. B. Check actual fl ow conditions; resize regulator for
minimum and maximum fl ow; if necessary, replace
with smaller regulator.