Cla-Val 49-01/649-01 Technical Manual - Manual (Page 5)

Rate of Flow Controller & Pressure Reducing Valve
INSTALLATION / OPERATION / MAINTENANCE
49-01
MODEL
INTRODUCTION
This manual titled the 49-01 Series Combination Rate of Flow
Controller and Pressure Reducing Valve contains information for instal-
lation, operation and maintenance of the valve and control system.
The Cla-Val 49-01 is an automatic valve designed to reduce a higher
inlet pressure to a steady lower downstream pressure regardless of
changing flow rate and/or varying inlet pressure, as long as the flow rate
is below a preset maximum. The automatic valve also prevents exces-
sive flow by limiting flow to a preselected maximum rate.
The Cla-Val 49-01 is a single seated, hydraulically operated, pilot con-
trolled diaphragm type globe or angle valve. The pilot system includes
a direct acting, spring loaded, pressure reducing pilot (CRA) and a rate
of flow differential control (CDHS-18).
INSTALLATION
1. Allow sufficient room around the valve to make adjustments and for
disassembly.
2. It is recommended that gate or line block valves be installed
upstream and downstream of the Cla-Val valve assembly to facilitate
isolating the valve for preventive maintenance.
NOTE: BEFORE THE VALVE IS INSTALLED, PIPE LINES SHOULD
BE FLUSHED OF ALL CHIPS, SCALE AND FOREIGN MATTER.
3. Place valve in line with flow through the valve in the direction indi-
cated on the inlet plate or by flow arrows. Check all fittings and hard-
ware for proper makeup and that no apparent damage is evident. Be
sure main valve cover nuts/bolts are tight. Pressure in some applica-
tions can be very high so be thorough in checking and inspecting for
proper installation and makeup.
4. For best control, it is recommended that the orifice plate restriction
be installed 1 to 5 pipe diameters downstream of the main valve. The
flow arrows should be pointing to the downstream side of the system.
5. A sensing line, supplied by other than Cla-Val, must be connected
between the orifice plate holder and the Differential Control. See dotted
lines on schematic drawing.
6. Cla-Val Valves operate with maximum efficiency when mounted in
horizontal piping with the cover UP; however, other positions are
acceptable. Due to size and weight of cover and internal components
of six inch valves and larger, installation with the cover up is advisable.
This makes periodic inspection of internal parts readily accessible.
7. Caution must be taken in the installation of this valve to insure
that galvanic and/or electrolytic action does not take place. The
proper use of dielectric fittings and gaskets are required in all sys-
tems using dissimilar metals.
OPERATION AND START-UP
1. Operation of the Cla-Val 49-01 Series Valve is fully automatic once the
flow rate and reduced pressure settings have been made. Modulation
in the main valve is brought about by the action of the pressure reduc-
ing and differential pilot controls. Throttling of either of these controls in
response to changes in the flow rate or downstream pressure produces
a change in the flow rate through the control system. This, in turn, caus-
es changes in the main valve cover chamber pressure.
It is the constant variations of main valve cover chamber pressure which
forces the main valve to seek new throttling positions in response to
slight changes in the flow rate or downstream pressure.
The controls are so arranged that the reducing control is in command
of the main valve only when the flow rate is below the setting of the dif-
ferential control. The valve, therefore, holds a constant delivery pres-
sure. If, however, the flow rate reaches the preset maximum the differ-
ential control takes command and holds the flow rate at the desired max-
imum. Under these conditions of increased demand the downstream
pressure falls below the normal reduced pressure.
2. Prior to pressurizing the valve assembly, make sure the necessary
gauges are installed, to measure required pressure and flow, as desig-
nated by the system engineer. A Cla-Val X101 Valve Position Indicator
may be installed in the center cover port to provide a visual indication
of the stem position during startup adjustment.
CAUTION: During startup and test procedures a large volume of water
may be discharged downstream. Check that the downstream venting is
adequate to prevent damage to personnel and equipment.
3. With the downstream block valve closed, slowly open upstream block
valve. If isolation valves are installed, as shown on the schematic, open
these valves slowly.
4. Carefully loosen the pipe plug at top of cover assembly. If a Valve
Position Indicator is installed, loosen the vent plug at top of Indicator.
Bleed air from cover and retighten plug.
5. Carefully loosen tube fittings at highest points and bleed air from sys-
tem. Retighten fittings.
NOTE: Be sure the sensing line (dotted line shown on schematic), which
connects the orifice plate to the CDHS-18 and the CRA Control, is
installed. This sensing line is supplied by the contractor or others. The 49-
01 system will not function unless this sensing line is installed. The line
should be routed without any high spots above the control connections.
Be sure to bleed air from line at the control fittings.
6. Turn the CRA Control adjusting screw clockwise until spring is fully
compressed. DO NOT FORCE. This puts the control in a full open
mode.
7. Slowly open downstream block valve and adjust the CDHS-18 Control,
turning the adjusting screw slowly counterclockwise until the main valve
closes. Adjust for rate of flow by turning adjusting screw slowly clock-
wise.
8. Reduce flow rate to a value below the setting of CDHS-18 Control by
closing downstream block valve or other means, then turn the adjust-
ment screw on the CRA Control counterclockwise until the main valve
begins to close. Adjust for outlet pressure requirements.
9. Check operation of controls by changing flow and pressure in the pip-
ing system.
10. If opening and closing speed controls (Cla-Val CV) are installed on
the valve assembly, fine tune the opening and closing speed of the main
valve while performing step 9.
11. The rate of flow and pressure reducing feature is outlined in Cla-Val
engineering drawing 76573 included in this manual.
MAINTENANCE
1. Cla-Val Valves and Controls require no lubrication or packing and a
minimum of maintenance. However, a periodic inspection schedule
should be established to determine how the fluid handled is affecting the
efficiency of the valve assembly.
2. Repair and adjustment procedures of the main valve and control
components are included in separate sections of the manual.
Accessory components are listed for reference.
3. Refer to the Service Suggestions Chart to identify operation symptoms.