Cashco DAP - Manual

INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM) IOM-DAP
11-13
I. DESCRIPTION AND SCOPE
Model DAP is a pressure reducing regulator used to control downstream (outlet or P2) pressure. Sizes are 1/2"
(DN15), 3/4" (DN20), 1" (DN25), 1-1/2" (DN40), and 2" (DN50). With proper trim uti li za tion, the unit is suitable for
liquid, gaseous, or steam service. Refer to Technical Bulletin DAP-TB for design conditions and selection rec om-
men da tions. (NOTE: This product was formerly identifi ed as a Model DP.)
This manual does not include any instructions related to the various methods of pressure loading a Model DAP
main valve.
MODEL DAP
DAP - DIRECT-ACTING, PRESSURE LOADED, DIAPHRAGMLESS
PRESSURE REDUCING REGULATOR
II. REFERENCES
Refer to Technical Bulletin DAP-TB for tech ni cal
specifi cations for this regulator.
ABBREVIATIONS
CCW – Counter Clockwise
CW – Clockwise
ITA – Inner Trim Assembly
III. INSTALLATION
SECTION III
SECTION II
SECTION I
CAUTION
For welded installations, all internal trim parts, seals and
diaphragm(s) must be removed from reg u la tor body prior
to welding into pipeline. The heat of fusion welding will
dam age non-metallic parts if not re moved. NOTE: This does
not apply to units equipped with extended pipe nip ples.
1. Regulator may be rotated around pipe axis 360
degrees. For ease of maintenance, the rec om-
mend ed position is with the cover dome (25)
up wards. In liquid service it is recommended that
the cover dome (25) be oriented down wards, and
that a cus tom er supplied and installed vent valve
be pro vid ed at the external sensing connection to
bleed-off trapped gas/air under the large piston
(77).
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. A pipeline strainer is
recommended before inlet to remove typical pipe-
line debris from entering regulator and damaging
internal “soft goods”, primarily the dynamic seal
and seat.
CAUTION
Installation of adequate overpressure pro tec tion is recom-
mended to pro tect the reg u la tor from overpressure and
all down stream equip ment from damage in the event of
regulator failure.
4. Downstream Sensing Installation Considerations
– Internal or External Sensing:
a. The regulator may be installed with internal or
external sensing. Unless otherwise spec i fi ed,
the regulator is supplied by factory with internal
sensing. The regulator may be con vert ed in
the fi eld to external sensing.(See Section VII
Maintenance, Part E – Converting Internal/
External Sensing.
b. Reference DAP-TB, Table DAG-11 for rec om-
men da tions for applying external pressure
sensing.
c. For internal sensing, no external line is re-
quired. For external sensing, use an external
control line. The line is connected from the 1/4"
(DN8) NPT tap (Port 5 – See Fig. 1) on the
side of the body di a phragm fl ange to a pres-
sure tap down stream of the regulator. Use 1/4"
or 3/8" outer di am e ter tubing or 3/8" (DN10)
pipe having an inner di am e ter equivalent to
schedule 40 pipe.