Cashco DA2 - Positive Differential - Manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-DA2
11-13
I. DESCRIPTION AND SCOPE
The Model DA2 is a differential pressure reducing regulator used to control differential pressure between down-
stream (outlet or P
2
) pressure and a loading (P
Load
) pressure to the spring chamber. Sizes 1/2" (DN15), 3/4"
(DN20), 1" (DN25), 1-1/4" (DN32), 1-1/2" (DN40), 2" (DN50), 2-1/2" (DN65), 3" (DN80) and 4" (DN100). With
proper trim uti li za tion, the unit is suitable for liquid, gaseous, or steam service. Refer to Technical Bulletin DA2-
TB for design conditions and selection recommendations.
MODEL DA2
DIRECT-ACTING, POSITIVE BIAS DIFFERENTIAL
PRESSURE REDUCING REGULATOR
SECTION I
II. REFERENCES
Refer to Technical Bulletin DA2-TB and DAG-TB for
tech ni cal specifi cations.
ABBREVIATIONS
CCW – Counter Clockwise
CW – Clockwise
ITA – Inner Trim Assembly
6. Clean the piping of all foreign material including
chips, welding scale, oil, grease and dirt before
in stall ing the regulator. Strainers are rec om-
mend ed.
7. In placing thread sealant on pipe ends prior to
en gage ment, ensure that excess material is
re moved and not allowed to enter the regulator
upon startup.
8. Flow Direction: Install so the fl ow direction
match es the arrow cast on the body.
9. If the loading pressure is not lowered suffi ciently
prior to shutting off the process fl uid supply,
then the diaphragm will be damaged with the
standard construction. The startup, shutdown,
and emergency operating procedures should be
reviewed to ensure that the loading pressure is
less than 50% of the Diaphragm Proof Rating
(See Table 1) before shutting off the process fl uid
supply pressure. If the regulator is specifi ed with
a fully supported diaphragm, then the diaphragm
will withstand a loading pressure equal to the
Diaphragm Proof Rating for the fully supported
diaphragm.
SECTION III
SECTION II
1. Regulator may be rotated around pipe axis 360
degrees. For ease of maintenance, the recom-
mended position is with the spring chamber (4)
upwards. In liquid service it is recommended that
the spring cham ber (4) be oriented downwards,
and that a cus tom er supplied and installed vent
valve be pro vid ed at the external sensing con-
nec tion to bleed-off trapped gas/air under the
di a phragm.
2. Provide space below, above, and around reg u la-
tor for removal of parts during maintenance.
3. Install block valves and pressure gauges to pro-
vide means for adjustment, operation, bypass,
or removal of the regulator. An isolation valve
on the loading line is not rec om mend ed.
4. An outlet pressure gauge should be located ap-
prox i mate ly ten pipe diameters downstream, and
within sight. A loading pressure (or differential
pressure) gauge is rec om mend ed.
5. All installations should include a downstream
re lief device if the inlet pressure could exceed
the pressure rating of any downstream equip-
ment or the maximum outlet pressure rating of
the unit.
III. INSTALLATION