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IOM-8310HP/LP-BASIC
SECTION III
III. PRINCIPLE OF OPERATION
1. Movement occurs as pressure variations register on the
diaphragm. The registering pressure is the outlet P
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or downstream pressure. The range spring opposes
diaphragm movement. As outlet pressure drops, the
range spring pushes the diaphragm down, opening
the ports; as outlet pressure increases, the diaphragm
pushes up and the port opening closes.
2. A complete diaphragm failure will cause the regulator
to fail open.
IV. START-UP
1. Start with the block valves closed. A bypass valve may
be used to maintain outlet pressure in the downstream
system without changing the following steps.
2. Relax the range spring by turning the adjusting screw
counter clockwise (CCW) (viewed from above) a min-
imum of three (3) full revolutions. This reduces the
outlet (downstream) pressure setpoint.
3. If it is a “hot” piping system, and equipped with a by-
pass valve, slowly open the bypass valve to preheat
the system piping and to allow slow expansion of the
piping. Ensure proper steam trap operation, if installed.
Closely monitor outlet (downstream) pressure via gauge
to ensure not over-pressurizing.
NOTE: If no bypass
valve is installed, extra caution should be used in start-
ing up a cold system; i.e. do everything slowly.
4. Crack open the outlet (downstream) block valve.
5. Slowly open the inlet (upstream) block valve observing
the outlet (downstream) pressure gauge. Determine if
the regulator is flowing. If not, slowly rotate the regulator
adjusting screw clockwise (CW) (viewed from above)
until flow begins.
6. Continue to slowly open the inlet (upstream) block valve
until fully open.
SECTION V
V. SHUTDOWN
1. On systems with a bypass valve, and where system
pressure is to be maintained as the regulator is shut
down, slowly open the bypass valve while closing the inlet
(upstream) block valve. Fully close the inlet (upstream)
block valve. (When on bypass, the system pressure
must be constantly observed and manually regulated.)
Close the outlet (downstream) block valve.
Do not walk away and leave a bypassed regulator
unattended!
2. If the regulator and system are to both be shutdown,
slowly close the inlet (upstream) block valve. Close the
outlet (downstream) valve only if regulator removal is
required.
7. Continue to slowly open the outlet (downstream) block
valve, especially when the downstream piping system
isn’t pressurized. If the outlet (downstream) pressure
exceeds the desired pressure, close the block valve
and go to Step 2, then return to Step 4.
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.
NOTE: The needle
valve (39) is shipped in a full open position. If the system
is unstable due to pressure fluctuations, slowly close
the needle valve (39) until the system becomes stable.
This needle valve (39) should never be in a fully closed
position.
9. Develop system flow to a level near its expected normal
rate, and reset the regulator setpoint by turning the
adjusting screw CW (viewed from above) to increase
outlet pressure, or CCW to reduce outlet pressure.
10. Reduce system flow to a minimum level and observe
setpoint. Outlet pressure will rise from the setpoint
of Step 9. The maximum rise in outlet pressure on
decreasing flow should not exceed the stated upper
limit of the range spring by greater than 10%; i.e. 10-40
psig (.69-2.8 Barg) range spring, at low flow the outlet
pressure should not exceed 44 psig (3 Barg). If it does,
consult factory.
SECTION IV
CAUTION C
DO NOT HYDROSTATIC TEST THRU AN INSTALLED
UNIT; ISOLATE REGULATOR FROM TEST. The upper
range spring pressure level listed on the nameplate is
the recommended “upper operative limit” for the sensing
diaphragm (see Section IV. Start-up, Number 7.) Higher
pressures could cause internal damage. In addition, note
on the nameplate that the Inlet and Outlet pressure and
temperature ratings are at different levels.
10. Basic Regulator - (Refer to Figure 1): Regulator may
be rotated around the pipe axis 360°. Recommended
position is with spring chamber vertical upwards. Orient
such that the spring chamber vent hole does not collect
rainwater or debris.
11. Regulators are not to be direct buried underground.
12. For insulated piping systems, recommendation is to not
insulate regulator.
CAUTION D
