IOM-POSR-1
3
6. Slowly open the inlet (upstream) block valve
ob serv ing the outlet (downstream) pres sure
gauge. De ter mine if the reg u la tor is flowing.
If not, slightly close bypass valve, and then
slowly rotate the pilot valve adjusting screw
clock wise (CW) (viewed from above) until flow
begins.
For POSR-1-20 in crease load ing pres sure
until flow begins.
the loading pressure to decay through the
bleed orifice. The reduced load ing pres sure
on the upper side of the di a phragm closes
the main valve’s plug enough to re store the
down stream (P
2
) pressure to the setpoint.
7. Pressure setpoint is adjusted by changing
the com pres sion of the pilot’s range spring by
turning the adjusting screw either clockwise
(CW) or counter-clock wise (CCW). Turning the
adjusting screw clockwise (CW) will in crease
the downstream (P
2
) pressure. Turn ing the
adjusting screw counter-clockwise (CCW) will
decrease the down stream (P
2
) pressure.
SECTION IV
IV. START-UP
A. General
1. Start with the block valves closed.
2. Ensure that the needle valve(s) on the sens ing
line is opened and downstream (P
2
) pres sure
is in di cat ing on pressure gauge.
3. Relax the pilot valve range spring by turning
the adjusting screw counter clockwise (CCW)
(viewed from above) a minimum of three
(3) full revolutions. This reduces the outlet
(down stream) pressure setpoint.
For POSR-1-20 use manual loading valve to
set minimum loading pressure.
senses the reduced pressure and the pilot
valve’s plug increases its opening, elevating
the load ing pressure on the upper side of the
main valve’s diaphragm. The combined actions
increase flow enough to restore the down stream
(P
2
) pressure to the setpoint.
6. If the downstream (P
2
) pressure rises above the
setpoint, the force developed by the in creased
pressure on the underside of the diaphragm
instantly moves it upward and partially closes
the main valve’s plug. Si mul ta neous ly, the
pilot valve’s plug partially clos es and al lows
Outlet Pressure - P
2
psig (Barg)
Loading Pressure - P
3
, psig (Barg)
@ P
1
Minimum
@ P
1
Maximum
5 (0.34)
15 (1.03)
25 (1.7)
50 (3.45)
60 (4.1)
70 (4.8)
100 (6.90)
110 (7.6)
120 (8.3)
130 (8.97)
145 (10.0)
150 (10.3)
135 (9.31)
150 (10.3)
– ( – )
4. Slowly open the bypass valve to preheat the
system piping and to allow slow ex pan sion
of the piping. Assure proper steam trap
op er a tion. Closely monitor outlet (down stream)
pressure via gauge to assure not over-
pres sur iz ing.
NOTE:
If no bypass valve is
in stalled, extra caution should be used in
start ing up a cold system; i.e. do ev ery thing
slowly.
5. Slowly open the outlet (downstream) block
valve until fully open. Slightly close the by pass
valve at same time.
CAUTION
Do not walk away and leave a bypassed reg u la tor
unattended when on manual bypass!
7. Continue to alternate slow ly closing the
bypass valve and then slowly opening the inlet
(upstream) block valve, es pe cial ly when the
down stream piping sys tem isn’t pressurized.
If the outlet (downstream) pressure exceeds
the desired pressure, close the bypass valve
until fully closed. If outlet pres sure still re mains
above desired level, rotate pilot’s ad just ing
screw CCW (viewed from above) in 1/2
rev o lu tion in cre ments until out let pres sure
reach es de sired level. If outlet pres sure is
below de sired level, ro tate pilot’s ad just ing
screw CW (viewed from above) until de sired
level is reached.
For POSR-1-20 adjust manual loading valve to
either increase or decrease loading pres sure
until desired set point is reached. Do not
exceed limits.
CAUTION
Do not exceed Maximum Loading Pressure limits for P
2
set point.
