Cashco 5100 User Manual

INSTALLATION, OPERATION AND MAINTENANCE MANUAL (IOM)

Model 5100 Pilot Operated

Pressure / Vacuum Relief Vent

I. DESCRIPTION AND SCOPE

IOM-5100

09-09

end-of-line

SECTION I

The maintenance of this Pilot Operated Vent Valve
(POVV) should only be done by quali ed valve
technicians. It is important that the technician be
familiar with the API and corporate standards,
corporate safety policies and the relief vent
manufacturer requirements. When repair services
are performed by an outside company, the company
needs to be a Cashco factory authorized repair
center which specializes in low pressure venting
devices.

II. VALVE DESIGN AND FUNCTION

The Model 5100 Pilot Operated Vents are used on
liquid storage tanks and other process vessels or
systems to prevent structural damage during the
process of  lling or emptying of a tank or for changes
in atmospheric conditions. Excess pressure is
vented to atmosphere..

Storage tanks are pressurized when liquid is
pumped in, compressing the existing vapor or
when increasing temperature causes increased
evaporation or expansion of existing vapor.
Conversely, a vacuum may be created when  uid
is pumped out or as atmospheric temperature
decreases. To prevent structural damage, vapor
must be allowed to escape or enter the tank at a
speci ed  ow rate. The volume rate of venting is
dependent on the tank size, displacement rate and
the  ash point of the  uid. See API Standard 2000
for procedures to determine venting requirements.

For information on repair centers in your area, please
contact:

Valve Concepts, Inc.
%Cashco, Inc.
607 West 15
Ellsworth, KS 67439-0006
[phone] (Phone)
[phone] (Fax)

SECTION II

th

Street

Thus the vent valve is capable of operating at
pressures closer to the maximum allowable
working pressure of the tank. Operating at higher
pressures reduces evaporation and total venting
volume, thereby reducing product loss and the cost
of handling emissions.

Each application must be reviewed to ensure ma­terial compatibility with all metal and soft good
components with the service conditions. The pallet
assembly, wetted components and tubing are 316
SST. Diaphragm material is FKM, unless speci ­cied otherwise.

The pilot valve is factory set to comply with the
speci cations on the purchase order. The adjust­able pressure range is a function of the installed
spring and will be stamped on the metal nameplate.
The set point pressure maybe changed within the
design parameters of the spring while installed on
line or in a maintenance shop. See Section IX
for setting and testing procedures.

A pilot operated relief vent has two principal
advantages over other relief vent designs:

1. Bubble tight shutoff up to 100% of set point.

2. Full open capacity for pressure relief is achieved
within 10% above set point.

This manual is intended to provide recommended
procedures and practices for installation, operation
and maintenance of the Model 5100 POVV. Al­though this manual cannot cover all possible con­tingencies, these guidelines will provide safe and
reliable pilot valve performance.

III. SAFETY WARNINGS:

SECTION III

WARNING

Warning: Before beginning any relief vent inspection
or maintenance, carefully read and understand the
information in this manual. If there are any questions
concerning the information in this manual, please
contact the factory or an authorized repair center
before proceeding.

Tank or system protection is the primary function of
the Pilot Operated Vent Valve (POVV). It must be
selected to meet the total pressure  ow requirements
within the maximum allowable working pressure
of the system on which it is installed. Consult API
Standard 2000 for tank protection sizing procedures.
Improperly speci ed relief vents may result in
structural damage to the tank or system, and can
cause severe personal injury or death.

In the event of a diaphragm failure, the Model 5100
will vent pressure to the atmosphere causing the
pressure relief valve to fail in the OPEN position.
The vent will now function like a weight loaded vent
under this condition with a lower set point. Consult
the factory for any questions related to this over­pressure condition.

CAUTION

DO NOT attempt to change pressure set point beyond
the limit speci ed on the nameplate..

The 1/2” OD SST pilot valve sensing line must be
kept open and unobstructed to ensure that the pilot
“senses” the actual tank pressure. For applications
where tank vapors may condense or polymerize in
the sensing tubing or the pilot valve, a nitrogen purge
may be required to prevent internal obstruction of the
tube. Consult the factory for recommendations.

CAUTION

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

After isolating the relief vent, bleed all pressure
from both main and pilot valve before removing the
Model 5100 POVV.

NOTE: Both the pilot valve and main valve are
exposed to the process vapors. Observe all
plant procedures and Material Safety Data Sheet
recommendations before inspecting, adjusting or
servicing any components.

The vent on the spring bonnet of the pilot must
be clean and unobstructed for proper and safe
operation of the valve.

SECTION IV

IV. SHIPPING, INSPECTION AND
STORAGE:

The POVV 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 POVV
should be stored in a clean environment with all
the protective  ange covers in place to prevent
intrusion of foreign materials. If there are indications
of physical damage or internal contamination, the
valve may need to be disassembled, cleaned and
inspected prior to installation.

2

Lifting lugs may be provided on the main valve for
lifting and handling. To avoid damage to the lower
 ange surface, rest the vent on a soft clean gasket
material until it is ready to be installed. DO NOT
store the POVV directly on the ground.

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,at installation.

IOM-5100

V. INSTALLATION:

SECTION V

The Model 5100 POVV is a precision device that
must be handled carefully to ensure seat tightness.

WARNING

The vent must be installed in a vertical position. 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  ange face be
within 1 degree of horizontal for best performance of
the venting device.

1. At installation, the POVV should be carefully
lifted into position using the lifting lugs on the
body. Use the case assembly (32,33) to help
align the body directly over the tank nozzle.
DO NOT use the pilot valve or pickup line to
pull the POVV into position.

2. Aluminum body vents should be mated to
 at-faced 125# ASME  anges. Mating  anges
should be  at within 0.020” and clean; free
of scratches, corrosion and tool marks. A full
faced gasket is recommended.

4. Center the gasket within the bolt circle of the
tank nozzle  ange.

5. Lubricate all studs and nuts with an appropri­ ate thread lubricant. If stainless steel studs
and nuts are required, use an anti-seize lubri­ cant such as moly-disul de.

6. Remove  ange protective covers and carefuly
set the POVV down on the gasket and face of
the nozzle  ange.

WARNING

Minimum clearance between tank roof and vacuum
inlet port must be at least equal to the vents’ nomi­nal  ange bore. Tank nozzle bore must be greater
than or equal to vent inlet  ange bore. Inlet piping
loads must be supported by appropriate structural

supports, NOT by the vent body.

7. Install lockwashers and nuts. Tighten nuts
to half the recommended torque value using
an alternating crossing pattern. See Table 2.

3. Install the  ange gasket on the nozzel face.
Use either a full faced or ring gasket for
raised face  anges. Ensure that the gasket
material is suitable for the service. See Table
1 for gasket dimensions.

Table 1

Body Flange Gasket Dimensions

CS, SST

150# ASME RF

2’ 4.12 2.38 -- -- --

3” 5.38 3.50 -- -- --

4” 6.88 4.50 -- -- --

6” 8.75 6.62 -- -- --

8” 11.00 8.62 -- -- --

10” 13.38 10.80 -- -- --

12” 16.12 12.80 -- -- --

Alum w/ 125#

ASME FF

2” 6.00 2.00 4.75 .75 4

3” 7.50 3.00 6.00 .75 4

4” 9.00 4.00 7.50 .75 8

6” 11.00 6.00 9.50 .88 8

8” 13.50 8.00 11.75 .88 8

10” 16.00 10.0 14.25 1.00 12

12” 19.00 12.00 17.00 1.00 12

O.D. I.D. B.C. Hole Qty

Table 2

Recommended Minimum Torque Values *

Size

2” 4 5/8”-11 31 81

3” 4 5/8”-11 43 106

4” 8 5/8”-11 29 68

6” 8 3/4’10 51 101

8” 8 3/4”-10 78 142

10” 12 7/8”-9 75 138

12” 12 7/8”-9 93 179

* Torque vlaues are based on a gasket factor m = 3.5,
gasket factor y = 4000 psi, operating pressure = 30 psi

Qty

Holes

Bolt

(UNC)

Torque (lb-ft)

Raised Face Flat Face

8. Make sure that the gasket is compressed
evenly and the  anges are not distorted.

NOTE: Misalignment of  ange faces will cause
bending stresses at the  ange and may damage
 ange joint.

9. Finish tightening nuts to the point that no ad­ ditional rotation occurs.

10. If loading weights were shipped separate from
the vent, install weights on vacuum pressure
pallet. Ensure that all packing has been re
moved.

IOM-5100

3

SECTION VI

VI. PILOT MAINTENANCE:

A. General:

1. Maintenance procedures herein after are
based upon removal of the pilot/vent valve
unit from the vessel/piping where installed.

2. Owner should refer to owner’s procedures for
re mov al, handling and cleaning of non re us­ able parts; i.e. gaskets, suitable solvents,
etc.

3. All indicated Item Numbers that are with
respect to the Pilot Assembly will be in
pa ren the sis and un der scored; i.e. (205). All
Item Numbers that are with respect to the
Vent Valve are not un der scored; i.e. (6).

B. Separation from Main Valve and Disassembly:

1. Disconnect sense tube (57) from  ttings
(48) and (244). Remove the pilot valve as­sembly from the nipple (53) by rotating the
pilot body (201) CCW.

2. Secure body (201) in vise with ‘sensing”
port facing front. Disconnect tubing (243)
from connectors (232),(234).

3. Paint or embed a match mark between
upper case (202), spacer (245) and lower
case (203) along  anged area. NOTE lo-

cation of 1/8” NPT tap from elbow (234) in
relation to body sensing port and straight
connector (232).

WARNING

SPRING UNDER COMPRESSION. Prior to re mov ing
 ange bolts, relieve spring com pres sion by backing
out the adjusting screw. Failure to do so may result
in  ying parts that could cause personal injury.

4. Rotate the closing cap (205) CCW for
removal. Loosen the adjusting screw nut
(214) two revolutions. Rotate Adjusting
screw (213) CCW and remove.

5. Remove diaphragm case nuts (209),
lockwashers (210),  at washers (221) and
cap screws (220). Grasp spring bonnet
(204) and lift up until diaphragm case (202)
clears top of spring button (212).

6. Secure spring bonnet (204) in a vice with
the upper diaphragm case (202) orientated
upwards.

7. Use 5/32” allen wrench to remove cap
screws (237) and lock washers (239) to
separate the bonnet (204) from the upper
case (202). Replace bonnet gasket (222)
and reassemble item numbers (202, 204,
237 and 239). Remove bonnet from vice
and set assembly aside.

8. Lift range spring (215) and spring button
(212), up and set aside.

9. Grasp the  at surfaces of wrench washers
(228) with a wrench and rotate piston stud
nut (235) CCW to remove nut, lock washer
(241), spring guide (211), washers (228).

10. Remove pressure ring (250), upper
pressure plate (246), upper diaphragm
(207) and spacer (245).

11. Remove upper diaphragm washer (219),
upper diaphragm gasket (226), and
diaphragm spacer (247).

For Intermediate & High Pressure Pilots Only:

Remove diaphragm case gasket (255)

and pressure ring (251).

12. Remove lower pressure plate (206), lower
diaphragm (207), lower diaphragm washer
(219) and lower diaphragm gasket (226).

13. Rotate 7/16” hex head cap screws (238)
CCW and remove lock washers (240).
Lift up on lower diaphragm case (203) to
remove. NOTE the alignment of the four

bolt holes and the sense hole in case (203)
with the holes in the body (201).

14. Grasp the cylinder (227) / piston (208)
assembly and lift upwards to extract this
assembly from the body (201). Remove
upper and lower body gaskets (225).

15. From top of assembly, press piston stud
(230) / piston (208) downward through
the center of the cylinder (227) to remove.
Apply Dow Corning 111 lubricant in o-ring
grooves and install new piston O-rings
(224).

4

IOM-5100