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IOM-3600 

           CAUTION

DO NOT attempt to remove the vent from the tank 
or process vessel without first bleeding all pressure 
from the system. ALTERNATIVE MEANS OF VACUUM 
RELIEF MUST BE PROVIDED WHEN THE VENT IS OUT 
OF SERVICE.

III. INSPECTION AND STORAGE

The vacuum relief vent is carefully packaged to 
prevent damage or contamination during shipping.  
Inspect the equipment when it is received and report 
any damage to the carrier immediately. The vent 
should be stored with all the protective flange covers 

           CAUTION

DO NOT change vacuum setpoint by adding additional 
weights to the pallet assembly without consulting 
Cashco Inc. or your VCI representative. 

The 3000 Series Vents are designed to mate to a 
flange. Torque guidelines are provided in Table 1. The 
Vents are 

NOT

 rated for full flange pressure and do 

not require high bolting torque.

Before installing any 3000 Series Vent, remove all 
packing materials from inside and outside the vent.  If 
loading weights were shipped separate from the vent, 
make sure to install the weights.  Tighten cover dome 
cap screws to 15 ft.-lbs.

           WARNING

The vent must be installed in a vertical position as 
shown in Figure 1. The tank nozzle on which the vent 
is mounted should have the same nominal diameter 
as the venting device. It is recommended that the tank 
nozzle flange face be within 1 degree of horizontal for 
best performance of the venting device.

II. SAFETY WARNINGS

Tank or system protection is the primary function of 
the weight loaded Vacuum Relief Vent. It must be 
selected to meet the total pressure and vacuum flow 
requirements within the Maximum Allowable Working 
Pressure and Vacuum of the system on which it 
is installed. Consult API Standard 2000 for tank 
protection sizing procedures. Improperly specified 
relief vents may result in structural damage to the 
tank or system and can cause severe personal injury 
or death.  

When Pipe-Away relief vents are used, back 
pressure in the header system will affect the set point 
of weight loaded vents by the amount of the header 
pressure. Maximum possible header pressure must 
be considered when sizing the pressure relief vent.

SECTION II

SECTION III

in place. Make sure that any loading weights that 
might have been shipped separately, to protect the 
vent during shipping, are accounted for and stored 
with the vent. These weights, when required, will be 
installed during installation. See Section IV.

SECTION IV

IV. INSTALLATION

NOTE:

 Wipe down the Seat Ring and Diaphragm 

when all the packing materials have been removed.

Inspect the gasket seating surface of the tank nozzle 
flange. It must be clean, free of scratches, corrosion, 
tool marks and flat.

FRP and Aluminum vents are furnished with flat 
faced flanges. It is recommended that they be 
installed on mating flat face flanges with a full faced 
gasket. If the flat face of the vent is sealing against 
a raised face steel flange, a spacer or filler ring must 
be used to fill the annular space of the raised face 
steel flange.

Make sure the gasket is suitable for the application.

Summary of Contents for 3000 SERIES

Page 1: ...verpressure conditions As the tank pressure increases as a result of product being pumped into the tank and or because of thermal expansion of the product and vapors the pressure pallet remains closed until the set pressure of the vent is reached When the tank pressure reaches the pressure setting of the vent the pressure pallet lifts allowing the tank pressure to bleed off Figure 2 illustrates th...

Page 2: ...ank or system protection is the primary function of the weight loaded Vacuum Relief Vent It must be selected to meet the total pressure and vacuum flow requirements within the Maximum Allowable Working Pressure and Vacuum of the system on which it is installed Consult API Standard 2000 for tank protection sizing procedures Improperly specified relief vents may result in structural damage to the ta...

Page 3: ...ual increments Proceed through the tightening sequence until the recommended torque is attained Recheck the torque on each bolt in the same sequence as bolts previously tightened may have relaxed through the torque sequence WARNING Minimum clearance between tank roof and vacuum inlet port must be at least equal to the vents nominal flange bore Tank nozzle bore must be greater than or equal to vent...

Page 4: ...ole on the pallet 26 Install new diaphragm 25 Re install diaphragm retainer 24 and washer secure nut 14 tight on stem Inspect and clean seat ring 16 NOTE FRP seat surfaces are integral inside the body Check seat surface for any nicks corrosion pitting or product build up Seat surface must be clean and smooth for vent to perform properly To Remove Seat Ring Make a match mark between the flange 1 an...

Page 5: ... Exercise care so as not to damage the pallet diaphragm and seat surface NOTE When installing the cover 8 ensure the pressure stem assembly 30 is inserted in the cover guide Place a new piece of TFE tape rope seal 34 0 on the face of the body cover flange See Figure 8 Place cover 8 over stem of pallet assembly align bolt holes with the body 1 and install cap screws 10 Using a star crossing pattern...

Page 6: ...e of leakage does not exceed SCFH for 6 inch size and smaller 5 SCFH for 8 inch to 16 inch or 20 SCFH for larger than 16 inch at 75 of set point then a vent is considered satisfactory for all practical purposes A test report should be completed for each vent The report should indicate the total pallet weight and the pressure achieved at the Test Flow Rate for both pressure and vacuum Other general...

Page 7: ...ed Serial Number typically 6 digits PARTS KIT for FIELD REPAIR Contact your local Cashco Inc Sales Repre sentative with the Serial Number and Product code Identifythepartsandthequantityrequired to repair the unit from the BOM sheet that was provided when unit was originally shipped NOTE If the BOM is not available refer to the cross sectional drawings included in this manual for part identificatio...

Page 8: ...8 Cover 9 Name Plate 10 Cap Screws 12 Pipe Plug 13 Upper Body 14 Nut ITEM NO DESCRIPTION 15 Socket Cap Screw 16 Seat Ring 24 Diaphragm Retainer 25 Pallet Diaphragm 26 Pallet 27 Stiffener Plate 28 Pallet Weights 29 Pallet Guide 30 Stem Assy Recommended Spare Part Early Models included a lock washer plain washer and a cotter pin Detail A Detail A ...

Page 9: ...PE LENGTH Size Item 34 0 Item 34 1 Item 34 2 2 23 17 20 3 25 20 22 4 33 28 26 6 38 34 32 8 38 34 32 10 46 41 39 12 56 47 47 14 58 51 55 Quantity 2 per unit ITEM NO DESCRIPTION 29 Pallet Guide 35 Indicator Housing 36 Indicator 37 Cable Connector 38 Cable ATEX 39 Cap Screw 40 Flame Bug Screen 41 Flame Screen Ring 42 Cap Screws ...

Page 10: ...et torque Check flange gap around circumference for uniformity If the gap is not reasonably uniform make the appropriate adjustments by selective tightening before proceeding Round 2 Tighten to 50 to 70 of target torque Check flange gap around circumference for uniformity If the gap is not reasonably uniform make the appropriate adjustments by selective tightening before proceeding Round 3 Tighten...

Page 11: ...ge NOTE Incorrect positioning and or selection of gasket s between the flanges will cause bending stresses at the flange that may damage the flange joint as bolting is tightened This is more likely to occur with aluminum or cast iron materials RECOMMENDATIONS FOR PROPER GASKET INSTALLATION Correct Installation Correct Installation Incorrect Installation Full Faced Gasket Spacer and Full Faced Gask...

Page 12: ...ct leads to heating or cooling of the process gas depends on the process gas and the inlet and outlet pressures The system designer is responsible for determining whether the process gas temperature may raise under any operating conditions 2 Where the process medium is a liquid or semi solid material with a surface resistance in excess of 1GΩ special precautions shall be taken to ensure the proces...

Page 13: ...A5 DA2 DA4 DA5 DA6 DA8 DA0 DA1 DAP SAP SLR 1 SLR 2 PTR 1 ALR 1 ULR 1 PGR 1 BQ BQ OPT 45 BQ CRYO 123 123 CRYO 123 OPT 45 123 OPT 46G 123 1 6 123 1 6 OPT 45 123 1 6 OPT 46G 123 1 6 S 123 1 6 S OPT 40 1000HP 1000HP OPT 37 1000HP OPT 45 1000HP OPT 45G 1000HP CRYO 1000HP 1 6 1000HP 1 8 1000LP 1000LP OPT 45 1000LP OPT 46G 6987 8310HP 8310HP 1 6 8310HP 1 8 8310LP 8311HP 8311LP 345 345 OPT 45 BA1 BL1 PA1 ...

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