Caution – Cashco 1000 HP Differential User Manual

Page 3

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3

IOM-1000HP-Dif fer en tial

IV. STARTUP

1. Start with the block valves closed. A by pass valve

may be used to maintain outlet pressure in the
down stream system without changing the fol low-
ing steps.

2. Remove closing cap and relax the range spring

by turning the adjusting screw counterclockwise
(CCW) a minimum of three (3) full revolutions.
This reduces the outlet (downstream) pressure
set point.

3. If it is a “hot” piping system, and equipped with

a bypass valve, slowly open the bypass valve
to pre-heat the system piping and to allow slow
expansion of the piping. Ensure proper steam
trap operation if installed. Closely monitor outlet
(down stream) pressure, via gauge, to en sure not
over-pressurizing. NOTE: If no bypass valve is
in stalled, extra caution should be used in starting
up a cold system; i.e. do everything slow ly.

Do not walk away and leave a bypassed reg u la-

tor unattended!

4. Crack open the outlet (downstream) block

valve.

5. Slowly open the inlet (upstream) block valve ob-

serv ing the outlet (downstream) pressure gauge.
De ter mine if the regulator is fl owing. If not, slowly

rotate the regulator adjusting screw clockwise
(CW) until fl ow 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 sys tem isn’t pressurized. If the outlet (down-
stream) pressure exceeds the desired pressure,
close the block valve and go to Step 2, then return
to Step 4.

8. When

fl ow is established steady enough that the

outlet (downstream) block valve is fully open, begin
to slowly close the bypass valve if installed.

9. Set the regulator set point (P

set

) by turning the

ad just ing screw clockwise (CW) to increase out-
let pres sure or CCW to reduce outlet pressure.
The outlet (P

2

) pressure under these conditions

will approximate the desired dif fer en tial pressure
when loaded with P

Load

.

10. Pressurize the source of loading (P

Load

) pres sure

and allow to fi ll the spring chamber cavity. Slightly
open the bleeder valve to vent any air as the spring
chamber is fi lling.

11. Develop system fl ow and pressure and readjust

set point as required to obtain desired response.
Per for mance should be analyzed at minimum and
maximum fl ow levels.

12. Install closing cap.

SECTION V

CAUTION

Loading Pressure must be shut off before shut ting
down the system pressure.

1. To prevent force imbalances and possible di a-

phragm failure, the loading pressure (P

Load

) should

always be shutdown fi rst from its source of pres sure.
Systems se quenc ing must ensure this oc curs.

CAUTION

2. It is recommended that manual operation not be at-

tempted by a bypass valve during a shutdown.

3. When the loading pressure (P

Load

) has been shut-

down, the regulator outlet pressure (P

2

) should

decrease substantially. When this is observed,
the inlet (upstream) block valve may be closed.

V. SHUTDOWN

SECTION IV

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