Steam Control Valve; Steam Valve Opening Pressure Adjustment - pick heaters 6X7 Service Manual

PICK VARIABLE FLOW SERVICE MANUAL
If water is not relieved from the heater in
this manner, the loop water will continue to
cool. The steam valve will continue to open,
eventually reaching a fully-open position.
The closed system will then be at steam
pressure. As a result, when a use point is
opened, the initial flow may consist of
steam. The temperature controller will bring
the steam valve back under control as steam
passes over it. Meanwhile, this steam will
continue through the water piping, to exit at
the use point.
SETTING THE RELIEF VALVE SEE
FIGURE 1.
1. Close the water outlet valve to
insure maximum static water
pressure.
2. Shut off the compressed air supply
to the temperature controller to
insure that the steam valve is closed.
3. Close the steam line block valve .
4. Turn the relief valve adjustment
screw counter clockwise to establish
a strong flow of water through the
relief valve. (Access to the
adjustment screw may be obtained
by removing the castle nut cover
seal on some valves).
5. Turn the adjustment screw
clockwise (retighten) until the flow
of water stops. Note that the valve
may drip for a short time until it
reseats completely.
6. Tighten the adjustment screw (turn
clockwise) an additional ½ turn.
Install and tighten the castle nut if
so equipped. (It is now set
approximately 15 psi above the
water pressure.
7. The valve is now reset. The water
outlet valve, steam block valve and
air supply to the temperature
controller, may now be opened.

STEAM CONTROL VALVE

IMPORTANT: Do not install valve
positioners. A valve positioner cases the
steam valve to move too fast to a new
position, resulting in hammer vibration
and poor temperature control. If
installed, place in a bypass, dampen or
remove the positioner.
STEAM VALVE LEAKAGE
Overheating of product when the steam
valve is closed is an indication of EXCESS
LEAKAGE. The maximum leakage rate
should not exceed .01% of full open valve
capacity (ANSI CLASS IV).
Steam leakage can be observed by
disconnecting the union or flange between
the steam valve and heater, then slowly
opening the block valve.
CAUTION: make sure that the
steam block valve is closed and
the heater is drained prior to
disconnecting the union or flange.
If excess leakage is observed:
Check valve travel stop (if applicable)
Disconnect the air line from the steam valve
actuator. If leakage decreases, either the
steam valve opening pressure is less than 3
PSI, or there is a temperature controller o I-
to-P transducer problem (if installed) which
is holding the steam valve slightly.
If the leakage still exists, the steam valve
requires repair. Please refer to the valve
service manual for instructions.
STEAM VALVE OPENING PRESSRUE
ADJUSTMENT
1. Close the steam block valve.
2. Set the temperature controller to it's
coldest setting.
Note: The following procedure may require
two people. People adjustments according to
the instructions in the separate actuator
manual.
3. Energize the interlock (3-way air
solenoid valve) if one is installed.
4. Slowly increase the output of the
temperature controller until the
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