Cashco DA1 - Manual (Page 6)

IOM-DA1 6
from the upper end of the cage (19).
c. Remove o-ring middle stem seal (14.2)
from piston-guide bearing (13).
d. Examine the com po nents (27.1, 27.2, 27.3,
27.4, 27.5, 27.6) of the dy nam ic side seal
(27) mechanism to de ter mine if signifi cant
leakage was oc cur ring. If the dy nam ic
side seal (27) shows signs of sig nifi cant
leakage, de ter mine if op er at ing con di tions
are ex ceed ing pres sure, pressure drop, or
tem per a ture limits.
Remove dynamic side seal (27) compo-
nents. Special care should be tak en when
using “tools” to remove the components
to ensure that no scratches are imparted
to any portion of the piston-guide bearing
(13) groove.
e. Remove wiper seal (16), if supplied, from
within cage (19).
f. Remove wiper washer (17.1), camber
adjusting washer (17.2), or seal retainer
(17.3), if sup plied, from within cage (19).
g. Remove o-ring lower stem seal (14.3) from
plug (20).
h. Remove seat ring (21); examine for signs
of leakage. If seat ring (21) shows signs of
signifi cant leakage, determine if op er at ing
con di tions of pressure, pres sure drop, or
temperature are ex ceed ing lim its.
c. Pull the valve plug (20) downwards and
out of the piston-guide bearing (13) and
out of the cage's (19) bottom while holding
the cage (19).
d. Remove the piston-guide bearing (13)
from the upper end of cage (19).
e. Examine the com po nents (27.1, 27.2,
27.3, 27.4, 27.5, 27.6) of the dy nam ic
side seal (27) mechanism to de ter mine
if signifi cant leakage was oc cur ring. If
the dy nam ic side seal (27) shows signs
of sig nifi cant leakage, de ter mine if op er -
at ing conditions are ex ceed ing pres sure,
pressure drop, or tem per a ture lim its.
Remove dynamic side seal (27) com po -
nents and discard. Special care should be
taken when using “tools” to remove the
components to ensure that no scratches
are imparted to any portion of the piston-
guide bearing (13) groove.
f. Remove wiper seal (16), if supplied, from
within cage (19).
g. Remove wiper washer (17.1) or camber
adjusting washer (17.2), if supplied, from
within cage (19).
h. Remove o-ring lower stem seal (14.3)
from plug (20).
i. Remove seat ring (21); examine for signs
of leakage. If seat ring (21) shows signs of
signifi cant leakage, determine if op er at ing
con di tions of pressure, pressure drop, or
temperature are ex ceed ing limits.
3. Clean all reusable metal parts according
to owner's pro ce dures. NOTE: On regula-
tors originally suplied as Special Cleaning
Option-55, -56, or -57, maintenance must
include a level of clean li ness equal to Cashco
cleaning standards of #S-1134, #S-1542,
#S-1589 re spec tive ly. Con tact factory for
de tails.
D. Inspection of Parts:
1. After inspection remove from the work area
and dis card the old “soft goods” parts (i.e.
o-rings, di a phragms, seals, gaskets, etc.) after
in spec tion. These parts MUST be re placed
with fac to ry supplied new parts.
2. Inspect the metal parts that will be reused. The
parts should be free of surface contaminants,
burrs, oxides, and scale. Rework and clean
the parts as necessary. Sur face con di tions
that affect the regulator per for mance are stated
below; replace parts that can not be re worked
or cleaned.
Figure 3: Assembled ITA,
Metal Diaphragm Construction
2. Units with Metal Diaphragm(s) (See Figure 3):
a. To disassemble the ITA, hold the lower
part of the valve plug (20) in a bench vise,
grasping on "fl ats" directly under seat
disc portion of plug (20). Do not hold on
the ma chined sur face in the plug's (20)
spin dle area. (The spin dle “slides” in the
pressed-in-place lower guide bush ing (24)
and can not be al lowed to be marred.)
b. Using a special double-posted spanner
wrench fi tting (to order see NOTE in
Section IX, Parts Ordering Information),
turn the piston-guide bear ing (13) CCW
to loos en; pis ton-guide bear ing (13) can
be re moved by hand after loos en ing.
"Flats"
13
27
15
17
19
21
20