CLA-VAL CDS7-DO Instruction manual

INTRODUCTION
The Cla-Val Model CDS7-DO Altitude Control
is a spring loaded, 3-way, diaphragm-actuated
control that provides high-level shut-off for Cla-
Val Altitude Control Valves. It remotely senses
pressure in the reservoir or tank. The DO fea-
ture provides an integral Delayed Opening
function for independently adjusting the dis-
tance between the high and low water level.
There are two altitude ranges available, 5 to 40
feet and 10 to 80 feet. The spring adjusting
screw can be set to stop flow into the reservoir
within these ranges. There is one delayed
opening range available: 1 - 16 feet.
INSTALLATION
The CDS7-DO Altitude Pilot Control is normally
supplied mounted on a Cla-Val 211 Series Altitude Valve which should
be installed in a horizontal run of pipe with the main valve cover up.
Two line block valves are recommended for valve servicing. If the
CDS7-DO is mounted from the main valve by a few feet, then it must
be installed with adjustment springs up for ease of adjustment and ser-
vicing. Consult factory for recommendations.
After the Cla-Val 211 Series Altitude Valve is installed in the pipeline
close to the reservoir, install the required remote sensing line from the
CDS7-DO to the reservoir or tank. The sensing line allows the CDS7-
DO to sense the static pressure head of the reservoir. The sensing line
should not be installed in the flowing line between the valve and the
reservoir or into turbulent flow area. These locations do not reflect the
true static head of the reservoir.
The remote sensing line should be 3/4" or larger copper tubing or
Schedule 40 PVC pipe. Galvanized pipe is not recommended. The
sensing line should slope (minimum 2 degrees) upward from the
CDS7-DO toward the reservoir to self-purge air out of the line. The
sensing line should have no high points to entrap air. A shutoff valve at
the reservoir connection is recommended. For above ground reser-
voirs, the connecting point for the sensing line should be a minimum of
12" to 18" above reservoir bottom (if filling from bottom) or at fill pipe
connection (if filling from side). Minimum high-level set-point adjust-
ment is approximately five feet above the remote sensing point of con-
nection.
Note: Please make sure to remove the plastic plug from the drain
port before putting the valve in service if pilot drains to atmosphere.
OPERATION, START-UP AND ADJUSTMENT
When the reservoir pressure (head) is lower than the setpoint of the
spring on the CDS7-DO Altitude Control ports "1" and "D" are intercon-
nected. This relieves the main valve cover pressure to atmosphere.
Line pressure then opens the main valve to start filling the reservoir.
Reservoir sensing pressure increases as the liquid level rises in the
reservoir. When the sensing pressure increases to the set point of the
CDS7-DO control spring, the control shifts interconnecting port "S" and
port "1". This pressurizes the main valve cover chamber and the main
valve closes.
By turning the lower adjusting screw of the CDS7-DO pilot, the liquid
level shutoff point will be changed. Turn the adjusting screw clockwise
to raise the liquid level shutoff point; counterclockwise to lower the liq-
uid level shutoff point. Follow the general operation and start-up
instructions regarding purging air from the valve control system.
ALTITUDE CONTROL WITH
DELAYED OPENING
CDS7-DO
MODEL
INSTALLATION / OPERATION / MAINTENANCE
300105-01
CDS7-DO
STOCK
NUMBER
ALTITUDE
RANGE
(FT H20)
5 - 40
NUMBER
OF
SPRINGS
15
ALTITUDE
CHANGE
PER TURN
DELAYED
OPENING
RANGE (FT)
CHANGE
PER
TURN
1 - 16 1

REASSEMBLY
1. Reassembly is in general, the reverse of disassembly.
REASSEMBLY OF BODY ASSEMBLY SECTION
1. Use the wrench flats on stem (11) to hold when tightening hex nut (34).
NOTE: Use caution when using wrenches to tighten the stem and
diaphragm assembly; careful not to damage special carbon coated sur-
faces on stem (11). A light coating of Dow Corning 33 grease, or equiva-
lent, should be applied to stem (11) before reassembly.
2. Clean and replace the Delrin ball (26) if necessary.
CAUTION: Do not overlook replacing this step; this small part plays a
critical role in proper operation of pilot.
3. Lubricate and replace both o-ring’s (41) and o-ring (40); clean and replace
poppet assembly (13) and center sleeve (14); firmly pressing until fitted
flush into upper body (12).
4. Clean surfaces of lower body (8); place on bench with serrations facing up.
5. Install lower body sleeve (18) into lower body (8).
6. Re-assemble the stem and diaphragm assembly that includes the stem
(11), lower diaphragm washer (10), diaphragm (7), o-rings (40 & 41),
upper diaphragm washer (9), lock washer (35) and hex nut (34).
NOTE: Use wrench flats on stem (11) to hold when tightening hex nut (34).
7. Install stem and diaphragm assembly into lower body (8).
8. Install upper body (12).
NOTE: Using the witness marks made in the dis-assembly procedures; to
correctly align the upper body (12) and lower body (8).
9. Install six of the eight bolts (30), six washers (33) and six hex nuts (31);
tightening securely. The remaining two eight bolts (30), two washers (33)
and two hex nuts will be installed later when re-installing the CDS7-DO
back onto the mounting bracket (27).
REASSEMBLY OF UPPER SPRING SECTION
1. Replace spring (19), lower guide (16) and upper guide (17).
2. Inspect, clean & reinstall adjustment stem assembly (20) into cover (15).
3. Clean O-Ring groove of cover (15).
4. Clean, lubricate and install O-Ring (43) into groove of cover (15).
5. Install cover (15) and four screws (32); tightening securely.
NOTE: Re-adjust the adjusting stem assembly (20) clockwise the same
number of turns as recorded in the disassembly instructions above. The
CDS7-DO Altitude Control Delayed Opening will now be reset to the
approximate set point as it was prior to disassembly.
REASSEMBLY OF LOWER SPRING SECTION
1. Install the two spring guides (4); one on each side of spring (19); placing
on top of exposed portion of stem (11).
2. Install cover (5) over spring & guides, installing eight screws (32); tighten-
ing securely.
NOTE: Re-adjust the adjusting screw (2) clockwise the same number of
turns as recorded in the disassembly instructions above. The CDS7-DO
Altitude Control will now be reset approximately for the same reservoir liq-
uid level shut-off point as it was prior to disassembly.
COMPLETING ASSEMBLY
1. Re-install CDS7-DO Altitude Control assembly back onto main valve;
using remaining two remaining bolts (30), two washers (33) and two hex
nuts (3); securely tightening onto bracket (27).
2. Replace previously removed control tube lines & fittings; securely tighten.
SERVICE SUGGESTIONS
INSPECTION
Under normal operating conditions the CDS7-DO Altitude Control will be
trouble free. Visually inspect and check pilot loop for leaks; check for any
continuous leaks from control tube(s), from the vent hole in the lower
cover or side drain port (“D”) on the CDS7-DO pilot.
The volume of drained water from the side drain port (“D”) of the CDS7-
DO pilot will vary according to the valve size. Continuous draining after
main valve has fully opened will indicate a problem. Refer to the service
suggestions to check for probable causes and remedies.
DISASSEMBLY
During preventive maintenance or service to the CDS7-DO Altitude
Control, all pressure to the control must be shutoff. The CK2 isolation
valve in the main valve control lines should be closed before starting dis-
assembly. Main valves 4" and larger have CK2 isolation valves installed,
however main valves smaller than 4" normally do not, therefore requiring
closure of shutoff valves in the main line at the valve inlet and outlet. The
isolation valve in the sensing line to the reservoir must also be closed.
WARNING: Failure to shutoff and release pressure prior to any disassem-
bly can result in serious damage to equipment or injury to personnel.
1. Disconnect and remove all control tubing’s from the CDS7-DO.
2. Remove two of the eight hex nuts (31) washers (33) and bolts (30) that
hold CDS7-DO to the mounting bracket (27).
3. Remove CDS7-DO Altitude Control from main valve to work on a
bench or clean area. Parts must be kept clean.
DISASSEMBLY OF LOWER SPRING SECTION
1. Remove cap (1), loosen hex nut (31) and unscrew adjusting screw (2)
counter clockwise from lower cover (5).
NOTE: Count the number of turns required to remove the adjusting
screw (2) counter clockwise; record this information for future refer-
ence when reassembling. This will allow the CDS7-DO Altitude
Control to be reset back to approximately the same reservoir liquid
level shut-off point, after being reassembled.
2. Loosen and remove the eight cover screws (32).
3. Remove cover (5), two spring guides (4) and spring (19).
DISASSEMBLY OF UPPER SPRING SECTION
1. Remove (22).
NOTE: Count the number of turns currently on the Adjustment Stem
Assembly (20) before removing; record this information for future ref-
erence when reassembling. This will allow the CDS7-DO to be reset
back to approximately the same set-point, after being reassembled.
2. Loosen and remove the four cover screws (32).
3. Remove cover (15), o-ring (43), upper spring guide (17), spring (19)
and lower spring guide (16).
4. Remove poppet assembly (13), center sleeve (14), o-rings (43) & (41).
NOTE: Use caution when using wrenches on poppet assembly (13);
be careful not to damage special carbon coated surfaces.
5. Remove Delrin ball (26).
CAUTION: Use care not to misplace this small part (it is important that
it be re-installed when re-assembling).
DISASSEMBLY OF BODY ASSEMBLY SECTION
NOTE: Before disassembly, apply a witness mark (a punch mark or
scratch) across upper body (12) and lower body (8). The mark is made
on each half of the assembly so that upon re-assembly the marks can
be later lined up in the correct position.
1. Loosen and remove the remaining six hex nuts (31), washers (33) and
bolts (30).
2. Separate the lower body (8) from upper body (12).
3. Remove the stem and diaphragm assembly that includes the stem
(11), lower diaphragm washer (10), diaphragm (7), O-ring (41), upper
diaphragm washer (9), lock washer (35) and hex nut (34).
NOTE: Use the wrench flats on stem (11) to hold when loosening hex
nut (34) to disassemble.
NOTE: Use caution when using wrenches to disassemble the stem
and diaphragm assembly; careful not to damage special carbon coat-
ed surfaces on the stem (11).
4. Inspect all parts for damage, wear and mineral deposits, clean thor-
oughly.
5. Inspect and clean the diaphragm (7); check for wear or cracks; replace
if required.
6. Check O-ring’s (40) and (42) for wear; replace if required. Inspect and
remove any deposits found in O-ring grove areas.
NOTE: Clean all metal parts thoroughly and replace damaged parts as
necessary. If, upon disassembly, sand and silt are found in the CDS7-
DO Altitude Control, every effort must be made to eliminate this prob-
lem. Filters, or relocating the reservoir sensing line may be required if
deposits are found in the sensing chamber of the control.
CLA-VAL
Copyright Cla-Val 2017 Printed in USA Specifications subject to change without notice.
1701 Placentia Ave •Costa Mesa CA 92627 Phone: [phone] •Fax: [phone] •E-mail: [email protected] •www.cla-val.com
©
N-CDS7-DO (06/2017)
Symptom Probable Cause Remedy
Leak from vent hole
in Lower Cover (5)
Diaphragm (7) damaged Replace
Diaphragm
Hext Nut (34) loose. Tighten Hex Nut
O-Ring (42) or Lower
O-Ring (41) damaged.
Replace O-Rings
(41) and/or (42)
Flow from Supply Port
(S) to Cover Port (1)
restricted.
Silt (foreign matter) in
upper cover.
Clear blockage.
Clean Poppet Assy (13),
and Center Sleeve (14).
Continuous leak from
Vent Port (D).
Main Valve closed.
Silt (foreign matter) in upper
cover, between Poppet Assy
(13) and seating surface of
upper cover (12).
Clean area.
Remove foreign matter.
Upper O-Ring (41) and
O-Ring (43) damaged.
Replace Upper O-Ring (41)
and O-Ring (43)
Continuous leak from
Vent Port (D).
Main Valve open.
Hytrol Main Valve Diaphragm
is damaged or Main Valve
Stem Nut loose.
Service Hytrol Main Valve.
Replace Main Valve
Diaphragm or tighten nut. *
*NOTE: Refer to 100-01 Hytrol IOM for detailed main valve disassembly/ reassembly instructions