CALEFFI 578 Serie Documentation Technique page 44

Installation - Operation - Maintenance
DESCRIPTION
The CLA-VAL Model CV Flow Control is a simply-designed,
spring-loaded check valve. Rate of flow is full flow in one di-
rection and restricted in other direction. Flow is adjustable in
the restricted direction. It is intended for use in conjunction
with a pilot control system on a CLA-VAL Automatic Control
Valve.
OPERATION
The CV Flow Control permits full flow from port A to B, and
restricted flow in the reverse direction. Flow from port A to B
lifts the disc from seat, permitting full flow. Flow in the reverse
direction seats the disc, causing fluid to pass through the cle-
arance between the stem and the disc. This clearance can be
increased, thereby increasing the restricted flow, by screwing
the stem out, or counter-clockwise. Turning the stem in, or
clockwise reduces the clearance between the stem and the
disc, thereby reducing the restricted flow.
.
INSTALLATION
Install the CV Flow Control as shown in the valve schematic.
All connections must be tight to prevent leakage.
MAINTENANCE
DISASSEMBLY
Follow the sequence of the item numbers assigned to the
parts in the cross sectional illustration for recommended order
of disassembly (see page CV001TT).
INSPECTION
Inspect all threads for damage or evidence of cross-threading.
Check mating surface of seat and valve disc for excessive
scoring or embedded foreign particles. Check spring for visi-
ble distortion, cracks and breaks.
Inspect all parts for damage, corrosion and cleanliness.
CLEANING
After disassembly and inspection, cleaning of the parts can
begin. Water service usually will produce mineral or lime de-
posits on metal parts in contact with water. If the deposit is
not removed after cleaning, then a fine grit (400) wet or dry
sandpaper can be used with water.
Rinse parts in water before handling.
Dry with compressed air or a clean, lint-free cloth.
Protect from damage and dust until reassembled.
REPAIR AND REPLACEMENT
Minor nicks and scratches may be polished out using a fine
grade of emery or crocus cloth; replace parts if scratches can-
not be removed. Replace o-ring packing and gasket each time
CV Flow Control is overhauled (see replace packing in the
spare parts liste). Replace all parts which are defective. Re-
place any parts which create the slightest doubt that they will
not afford completely satisfactory operation. Use Inspection
steps as a guide.
REASSEMBLY
Reassembly is the reverse of disassembly; no special tools
are required.
TEST PROCEDURE
No testing of the flow Control is required prior to reassembly to
the pilot control system on CLA-VAL Main Valve.
44
Serie 578
Flow Control Cock