Cashco 1088 User Manual
INSTALLATION, OPERATION AND MAINTENANCE MANUAL (IOM)
I. DESCRIPTION AND SCOPE
IOM-1088
06-05
Model 1088
Vacu-Gard Blanketing Valve
SECTION I
The Model 1088 Vacu-Gard is a tank blanketing valve
intended for installation on top of small storage tanks.
The standard valve comes with FNPT connections.
Flanges may be attached by adding nipples. Valve
bodies with welded fl anges may be ordered from the
factory. There are three styles of the Model 1088 this
SECTION II
II. PRIOR TO INSTALLATION
It is always good practice to clean out blanket gas
supply lines prior to valve installation to get rid of dirt,
sand, loose scales and other foreign particles trapped
in the piping. This is particularly true for new tanks and/
or new piping. One way to accomplish this is to blow
out the lines from the supply side up to the connection
to the Vacu-Gard inlet.
SECTION III
III. INSTALLATION
IOM will cover: internal sensing, integral dip-tube, and
remote sensing. The functionality of the unit will be the
same regardless of the sensing style. Please refer to
the applicable drawings in the back of this IOM manual
for recommended installation schematics.
CAUTION
Follow your company’s safety procedures to avoid
injury to personnel or damage to equipment.
It is always good practice to install a main line fi lter
upstream of any tank blanketing valve. The element
should be approximately 5-40 microns with a fl ow ca-
pacity equal to or greater than that of the Vacu-Gard.
The valve should be installed in the normal upright position. The inlet is horizontal and the outlet is vertical
downward. There is an optional horizontal outlet for remote sensing valves. This option is not available for
the integral dip-tube design. All outlet piping from the
valve body to the vessel must be as large or larger than
the outlet port in the body. Keep piping as short as possible for best valve performance.
For Internal Sensing:
Pipe as recommended above. Note that internal sensing yields only 25% of full capacity.
For Remote Sensing:
The sense line should be a 1/2” O.D. tube (or larger)
and the length should not exceed fi fteen feet. Longer
lengths may be used with larger diameter sense lines.
The sense line should slope downward from the valve
to the tank to allow condensate, if any, to drain back
into the tank. (The sense port is the port on the side of
the body marked with an “S”. A “tee” may be added to
the sense port for gauging pressure in the vessel.
For Dip-Tube Sensing:
The integral dip-tube line must protrude into the tank at
least 6” below the roof. NOTE: The port at the end of
the main valve body opposite the inlet is not a sense
port. (This port should not be used for pressure gauging since the pressure at this point may be higher than
the maximum tank pressue and may cause damage to
the gauge.) This port is an optional horizontal outlet for
remote sensing valve type.
CAUTION
NOTE: The sense chamber is not a dead-ended cham-
ber. In addition to the fl ow when the valve is open, there
is also a very small fl ow from the valve into the ves-
sel through the sense connection. Therefore the sense
tube must be large enough so that the fl ow will not be
restricted. Premature closing of the valve may occur if
excess pressure builds up in the sense chamber due to
a sense line that is too small.
SECTION IV
IV. START-UP
Operation of the Model 1088 is automatic once the set
pressure has been set. (The set pressure is usually
bench-set at the factory prior to shipment.) NOTE:
The set pressure is defi ned as the pressure at which
the valve should be fully closed on increasing tank
pressure.
Refer to applicable drawing dependent on sensing style.
Temporarily keep valve A closed. Use an appropriate
pressure indicating instrument for G2 to measure the
pressure in the vessel.
For external sensing open valves C and E, then valve
B. For internal sensing open valve B. For integral diptube proceed to the next step.
Now very slowly open valve A while watching gauge
G2. NEVER SLAM OPEN VALVE A! The Vacu-Gard
should close when the tank pressure reaches the set
SECTION V
A pressure/vacuum relieving device large enough to
vent excess pressure and to serve as an emergency
vacuum breaker must be installed to protect the tank.
CAUTION
DO NOT overtighten threaded connections since damage or breakage may result. Use tefl on tape and/or
anti-seize compound on pipe thread joints.
pressure. To adjust the set pressure, remove the hex
cap at the top of the valve and loosen the jam nut
around the adjusting screw. Clockwise rotation of the
adjusting screw will increase the set pressure. Counter
clockwise will decrease the pressure provided there is
a manual valve to vent the excess pressure. Do not set
the set pressure beyond the nameplate range. Tighten
the jam nut after adjustments are made and replace
the hex cap.
In the event that the adjusting screw is backed off without
compressing the spring, intentionally or unintentionally,
the valve will begin to open when the tank pressure
reaches about 1” w.c. vacuum.
CAUTION
DO NOT exceed the maximum inlet pressure on the
nameplate.
V. SHUT-DOWN
To shutdown the Vacu-Gard, reverse start-up procedure and bleed off trapped pressure before disassembly.
SECTION VI
VI. MAINTENANCE
The Model 1088 should be periodically actuated and
all sliding surfaces and seals lubricated to ensure
smoothness of operation. The frequency required
depends on the severity of the service conditions. At
least once a year is recommended.
If the valve must be disassembled for any reason, fi rst
make sure all pressure to the valve is blocked and
pressure trapped in the valve is vented safely. Refer to
your company procedure for any special precautions
when handling toxic or other hazardous materials.
2 IOM-1088
CAUTION
To disassemble the valve, refer to the appropriate
drawings.
The working components within the valve body may be
removed without the need to take apart the diaphragm
case. To remove the body internals, simply remove
the item 032 body plug. Be careful not to drop any
components. The item 025 spring could dislodge the
item 020 spindle during removal.
To disassemble the diaphragm case, relax the
compressed spring by fi rst unscrewing the item 001
cap, then loosen the item 003 jam nut and back off the
item 002 adjusting screw. The ring of nuts and bolts
around the periphery can now be removed.
Replace all parts that show signs of damage or excessive
wear. When a part is replaced, make sure the material
is suitable for the service, especially elastomeric
components. If an o-ring needs to be replaced, be sure
to use the correct size and material (see the paragraph
on Soft Goods Kits). Prior to reassembly, make sure all
parts are clean and free of contamination and seating
surfaces are free of deep scratches.
Reassemble in reverse order of disassembly. Use tefl on
tape and/or anti-seize compound on tapered pipe thread
joints. Use lubricant sparingly on other screw threads.
DO NOT overtighten threaded connections since
damage or breakage may result. Very lightly lubricate
all o-rings with a lubricant that is compatible with the
service. Sealing surfaces of gaskets and diaphragms
may also be lubricated. Assemble with special attention
to the following:
DIAPHRAGM CASE: Use one piece of item 027 body
gasket. Be sure the item 017 center bolt is installed with
the threaded end up. There is one item 018 bolt gasket
used between the center bolt and the lower item 016
support plate as shown on the drawing. There is also an
identical gasket used between the upper surface of the
item 013 sense diaphragm and the bottom side of the
upper item 016 support plate. This is to ensure a tight
squeeze on both sides of the sense diaphragm to effect
a tight seal. Item 014 ring gasket is always installed on
the top side of the sense diaphragm. Item 033 washers
are used to center the lower end of the spring. It may
sometimes be necessary to “thread” the spring onto
the washer or onto the item 006 spring button. You will
fi nd that turning the end of the spring in one direction
against the spring button or washers will tend to close
the coils and make installation more diffi cult. However,
turning the spring in the opposite direction will tend to
open the coils for easier installation.
threads on the item 032 body plug. Item 021 o-ring
(smaller than item 022 o-ring) is placed around the
outside internal groove at the lower end of the spindle.
ITEMS 021 AND 022 ARE SPECIAL O-RINGS AND
MUST BE ORDERED FROM THE FACTORY.
If the valve body is installed and in the nomral upright
position, stack the components on the body plug as
follows: insert item 025 return spring into the center
cavity of item 032 body plug. Insert item 024 guide pin
inside the return spring. Place item 020 spindle over
the return spring with the small diameter tip pointing
up. Place the item 019 strainer around the spacer.
Now slowly and carefully insert the stack into the body
cavity, allowing the components to align themselves
before threading on the body plug. Tighten until snug
to bottom of the spacer.
If the valve body is on a work bench, turn the body
upside down and install the internals as follows: insert
the item 020 spindle into the body with the small
diameter tip fi rst. Insert the item 026 spacer and let it
bottom in the body. Insert the item 019 strainer around
the spacer. Insert item 025 return spring into the
spindle cavity. Insert item 024 guide pin into the spring.
Place the center cavity of item 032 body plug over the
spring and slowly and carefully push against the spring
to thread on the body plug. Tighten until snug.
After the valve has been completely reassembled,
it may be installed and put into operation as outlined
above. If the valve will not shut off tight, check for
dirt or other foreign particles on the o-rings or seating
surfaces. Also check to make sure the body internals
have not been damaged by being forced into place.
BODY INTERNALS: Before installation, be sure item
023 o-ring is placed around the groove adjacent to the
3IOM-1088
ORDERING INFORMATION:
NEW REPLACEMENT UNIT vs PARTS "KIT" FOR FIELD REPAIR
To obtain a quotation or place an order, please retrieve the Serial Number and Product Code that was
stamped on the metal name plate and attached to the unit. This information can also be found on the Bill of
Material (parts list) that was provided when unit was originally shipped.) (Serial Number typically 6 digits).
NEW REPLACEMENT UNIT:
Contact your local Cashco, Inc., Sales Rep re sen ta tive with the Serial Number, Product code and the
pressure/vacuum settings. With this information they
can provide a quotation for a new unit including a
complete description, price and availability.
CAUTION
Do not attempt to alter the original construction of any
unit without assistance and approval from the factory.
All purposed changes will require a new name plate with
appropriate ratings and new product code to accomodate the recommended part(s) changes.
PARTS "KIT" for FIELD REPAIR:
Contact your local Cashco, Inc., Sales Rep re sen ta tive with the Serial Number and Product
code. Identify the parts and the quantity
required to repair the unit from the Bill of Materials sheet that was provided when unit was
originally shipped.
NOTE: Those part numbers that have a quantity
indicated under "Spare Parts" in column "A”
refl ect minimum parts required for inspection
and rebuild, - "Soft Goods Kit". Those in column “B” include minimum trim replacement
parts needed plus those "Soft Goods" parts
from column "A".
If the "BOM" is not available, refer to the crosssectional drawings included in this manual for
part identifi cation and selection.
Local Sales Representative will provide quotation for appropriate Kit Number, Price and
Availability.
4 IOM-1088
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