cashco DA1 Installation, Operation & Maintenance Manual - Page 2
Browse online or download pdf Installation, Operation & Maintenance Manual for Controller cashco DA1. cashco DA1 18 pages. Direct-acting, spring loaded pressure reducing regulator
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which allows the diaphragm chamber to
always be self draining. The external sensing
line may be sloped upward for liquids or gases.
DO NOT HYDROSTATIC TEST THROUGH AN
INSTALLED UNIT; ISOLATE REGULATOR FROM
TEST. The upper range spring pres sure level
on the nameplate is the rec om mend ed "upper
operating limit" for the sens ing diaphragm.
Higher pres sures could cause internal dam age.
In ad di tion, note on the nameplate that the Inlet
and Outlet pres sure and tem per a ture ratings
are at different levels.
IV. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations register
on the diaphragm. The registering pressure is the
outlet, P2, or downstream pressure. The range
spring op pos es di a phragm movement. As outlet
pressure drops, the range spring pushes the di a-
phragm down, opening the port; as outlet pres sure
V. STARTUP
1. Start with the block valves closed.
2. Relax the range spring by turning the ad just ing
screw CCW (viewed from above) a minimum of
three (3) full rev o lu tions. This reduces the outlet
(down stream) pres sure set point.
3. If it is a "hot" piping system, and equipped with
a bypass valve, partially open the bypass valve
to pre heat the system piping and to allow slow
ex pan sion of the piping. Ensure proper steam
trap operation if installed. Closely monitor outlet
(down stream) pressure via gauge to ensure not
over-pres sur iz ing. NOTE: If no bypass valve is
in stalled, extra caution should be used in starting
up a cold system; i.e. do everything slowly.
4. Crack open the outlet (downstream) block valve.
Do not walk away and leave a bypassed reg u la tor
unattended!
2
CAUTION
CAUTION
Installation of adequate overpressure pro tec tion
is recommended to pro tect the reg u la tor from
over pres sure and all down stream equip ment from
dam age in the event of regulator failure.
Supply
@ P 1
TR
(Shaded portion for steam/condensate systems)
Blowdown-
Drain
Recommended Piping Schematic
For Pressure Reducing Station
SECTION IV
increases, the diaphragm pushes up and the port
opening closes.
2. A complete diaphragm failure will cause the reg u-
la tor to fail open and fluid will discharge from the
spring chamber vent hole.
SECTION V
5. Slowly open the inlet (upstream) block valve to
about 25% open, observing the outlet (down-
stream) pres sure gauge. Determine if the reg u-
la tor is flowing. If not, slowly rotate the regulator
ad just ing screw CW (viewed from above) until
flow be gins.
6. Continue to slowly open the inlet (upstream) block
valve until fully open.
7. Continue to slowly open the outlet (downstream)
block valve, especially when the downstream pip-
ing system isn't pressurized. If the outlet (down-
stream) pressure exceeds the desired pres sure,
close the inlet block valve and go to Step 2. Close
bypass valve approximately 25%, and re peat
pro ce dure.
8. When flow is established steady enough that the
outlet (downstream) block valve is fully open, begin
to slowly close the bypass valve if installed.
CAUTION
SRV
Model DA1
Bypass
Reducing
Regulator
TR
Outlet
@ P 2
P1
Blowdown-
Drain
IOM-DA1