Cashco 521 User Manual
INSTALLATION, OPERATION & MAIN TE NANCE MANUAL (IOM)
MODEL 521
TOTAL TFE, GLOBE-PATTERN CON TROL VALVE
I. DESCRIPTION AND SCOPE
The Model 521 is a bellows sealed, globe-style control valve fabricated from a tee-block of isostatically
com pact ed virgin TFE. Sizes are 1/2", 1", 1-1/2" and
2". The split body jacket is CF8 (304 SST) material.
All wetted internal parts are of isostatically compacted
TFE material. The standard stem material is of 316
SST; two optional Hastelloy C-276 stem material
con struc tions are avail able.
End connections are available to mate with 150#,
300# or DIN PN16, 25 or 40 fl anges. Each fl ange
is drilled and tapped to receive stud bolting only.
IOM-521
12-13
BODY IOM
SECTION I
The valve is designed for chemical service with fl uids
that are normally corrosive to metallic materials.
For application pressure vs. temperature zone refer
to Model 521-TB, Graph No. 1 (pg. 3).
Actuators that may be mounted to a Model 521
body are Cashco Model C27 or Model C53, both
fi eld reversible.
II. REFERENCES
Refer to Technical Bulletin 521-TB for complete
tech ni cal specifi cations of a Model 521 coupled with
either Cashco Actuator C27 or C53.
www.cashco.com/techbulletins/521.pdf
Refer to following Installation, Operation & Main te nance Manuals (IOM’s) for either actuator and/or
devices that maybe mounted to a Model 521:
Actuators: www.cashco.com/IOM/C27-C53.pdf
Positioners:
P/P: www.cashco.com/techbulletins/9540l.pdf
I/P: www.cashco.com/techbulletins/srd991.pdf
I/P: www.cashco.com/iom/PS2iom.pdf
SECTION II
SST.......... Cast or Wrought Stainless Steel
HC ........... Wrought Hastelloy C-276
ATO-FC ... Air-to-Open, Fail Close
ATC-FO ... Air-to-Close, Fail Open
CCW ........ Counter Clockwise
CW ........... Clockwise
D or DIR ... Direct Acting
R or REV.. Reverse Acting
IAS ........... Instrument Air Supply
IOM .......... Installation, Operation and Maintenance
SIG .......... Output Signal from Instrument
LOAD ....... Positioner Output Air Pressure
V .............. Vent
Model 521
with ATO - FC Actuator
ABBREVIATIONS
Man u al
SECTION III
III. INSTALLATION
A. Orientation
1. Recommended orientation when installed is
in a hor i zon tal pipeline with the stem vertical. Valves may be installed in a vertical or
hor i zon tal pipeline with the stem between
vertical and horizontal.
2. Outdoors, all installations may be oriented
at any angle from horizontal-to-vertical, as
per A.1. above.
3. Model 521 valves should not be installed
with the stem oriented below horizontal/
down wards.
4. In no case is additional weight to be applied
to the actuator assembly when installed in
an ori en ta tion other than vertical.
WARNING
The valve/actuator unit should not be used as a
“step” to sup port per son nel. Failure to comply
may cause leak age at the bonnet/body joint, al low ing pos si ble con tact with harm ful fl uids.
2. If pipe reducers are located before and/or
after the valve body, keep the reducers as
close as practical to the valve body; this is
especially important where the reducers are
more than one line size larger than the valve
body size, which is common in gaseous
ser vice.
3. Clean the piping of all foreign debris, including chips, weld scale, weld splatter,
oil, grease, sand or dirt prior to installing
the control valve; THIS IS AN ABSOLUTE
REQUIREMENT.
4. Field hydrostatic testing the completed
piping system, including the Model 521,
to 1-1/2 x CWP in di cat ed on Model 521
name plate is ac cept able. If hydro test pres sure ex ceeds the 1-1/2 x CWP limit, the 521
must be re moved for such testing. Before
pres sur iza tion, the valve plug should be
lifted from the seat if of re verse, ATO-FC
action.
5. Flow Direction: Install so the fl ow direc-
tion match es the arrow cast on the valve
body.
6. Valves are not to be direct buried un der ground.
B. Piping System
1. It is recommended that the control valve unit
be installed with a double-block and bypass
as indicated in Figure 1. This arrangement
is recommended especially where main te nance will be done on the valve body while
still installed in the pipeline.
Figure 1: Typical Control Valve Station
7. Insulation may be applied as indicated in
Fig ure 2. Drainage from the packing area
must be ensured when fully installed, sealed
and lagged for outdoors installation. Vented
pipe plug (12) should not be covered.
Figure 2: Body Insulation
8. Undue piping stress/strain or bending
torques may not be transmitted thru the
control valve body. One pipe (inlet or outlet)
should be anchored rigidly for piping that
is “hot” or “cold” with respect to ambient
IOM-5212
tem per a ture; the re main ing pipe (inlet or
outlet) should be sup port ed and guided to
ensure uni di rec tion al ex pan sion/con trac tion. Properly align prior to installing valve
with required fl ange bolting.
9. The Model 521 is designed for a fl anged
con nec tion that is gasketless. The raised
face portion of end con nec tion fl ange serves
as the gasket.
10. An ANSI/DIN adapter gasket (17) is supplied with all Model 521 valves provided
with DIN 16/25/40 end con nec tions. See
Figure 3. The purpose of this adapter gasket
(17) is to en sure prop er compression of the
body’s TFE core (1.2) when used with DIN
piping.
To assist during installation, place pipe
thread sealant on one side of adapter gasket
(17), and press the sealant covered side of
the adapter gasket over the exposed TFE
of the body core (1.2) end connection. The
sealant will hold the adapter gasket (17)
to its proper location prior to joining with a
piping fl ange.
TABLE 1
Body Size End Connection Flange Bolting
In. (DN) 150# 300# DIN 16/25/40
1/2" DN15
1" DN25
1-1/2" DN40
2" DN50
No. Bolt Holes 4 4 or 8 * 4
1/2" Ø - 1-3/4"
13 UNC-2B
1/2" Ø - 2"
13 UNC-2B
1/2" Ø - 2-1/2"
13 UNC-2B
5/8" Ø - 2-1/2"
11 UNC-2B
* 2" - 300 # requires 8 bolt holes; all others 4.
1/2" Ø - 1-3/4"
13 UNC-2B
5/8 Ø - 2"
11 UNC-2B
3/4" Ø - 2-3/4"
10 UNC-2B
5/8" Ø - 2-3/4"
11 UNC-2B
14 mm Ø - 45 mm
M12x1.75-6H
14 mm Ø - 52 mm
M12x1.75-6H
18 mm Ø - 70 mm
M16x2.0-6H
18 mm Ø - 70 mm
M16x2.0-6H
12. Tighten fl ange stud nuts uniformly in a cross-
ing pattern. Ensure fl ange facing align ment.
Do not use fl ange bolting to “pull” fl ang es
into alignment. Tighten fl ange bolting to
torque levels of Table 2 in increments of
1/2 rev o lu tion to ensure uniform loading of
valve’s raised facing.
TABLE 2
Body Size End Connection Flange Bolting
In. (DN) ANSI-150 ANSI-300 DIN 16/25/40
1/2" DN15 10 - 12 ft-# 10 - 12 ft-# 15 - 18 N-m
1" DN25 10 - 12 ft-# 12 - 14 ft-# 21 - 25 N-m
1-1/2" DN40 10 - 12 ft-# 14 - 17 ft-# 18 - 22 N-m
2" DN50 35 - 40 ft-# 17 - 20 ft-# 50 - 60 N-m
Figure 3: ANSI/DIN Adapter Gasket
11. Flange bolting must be of the stud-type.
Each fl ange is drilled and tapped to accept
studs. The studs should be of a length to
penetrate the full depth of the bolt hole thru
the fl ange; DO NOT USE STUDS/BOLTS
OF TOO SHORT LENGTH. See Table 1
for stud size/thread/length requirements.
IOM-521
Figure 4: End Connection - Partial Section
NOTE: If the installed Model 521 has had
the fl ange bolting over-torqued, distortion
of TFE core (1.2) will occur. If dimension
“X” in Figure 4 is 0.040" (1 mm) or less, a
gasket is rec om mend ed upon reinstallation.
If dimension “X” is less than 0.020" (0.5 mm),
body re place ment is recommended.
3
C. Auxiliary Detection:
1. When a fl uid is known to permeate TFE over
a fi nite time period and the fl uid is lethal or
is subject to stringent limits of fugitive emis sions, the vented pipe plug (12) should be
removed and one of, or a com bi na tion of, the
following methods should be considered to
monitor the integrity of the internal primary
stem (9) seal – the bellows sub-assembly
(8):
a. gas detector with alarm
b. pressure indicating gauge
c. pressure switch with alarm
d. inert gas, constant fl ow purge.
SECTION IV
IV. STARTUP
A. General:
1. Ensure that the Model 521 unit has been
properly adjusted and calibrated, including
the po si tion er, if in stalled.
2. Recommend startup to be in “manual”
mode. This procedure assumes double
block (iso la tion) and bypass valves for the
“control valve station" per Figure 1.
3. Start with either of the two block valves
closed, with the other open. The bypass
valve should be closed. Pres sur ize system
if possible/prac ti cal.
4. Back out the airset’s adjusting screw until
loose.
5. Turn on air supply pressure.
6. Adjust the air supply airset (fi lter-regulator) to
the proper level as indicated in the technical
bulletin 521-TB. DO NOT STROKE THE
CON TROL VALVE WITH AN AIR SUPPLY
PRESSURE SET TING GREATER THAN
REC OM MEND ED MAX I MUM PRESSURE!
7. Place loop controller into “manual” mode.
Vary setting from minimum – mid-range—
maximum SIG out put. Ob serve response of
control valve unit to these changes of input
SIG. The valve should fully stroke at the
variation from minimum SIG to maximum
SIG; the mid-range SIG should have the
valve stem travel at/near 1/2 open.
8. Confi rm that action of controller and po si-
tion er – direct or reverse – are producing
the desired response in the control unit.
Confi rm that the control valve “fail” position
is as re quired.
9. Hereafter, the procedure assumes that
actual fl uid fl ow may be established. This
may not be practical/pos si ble in all cases;
if so, vary pro ce dure as required.
Always “heat” or “cool” down the system
pip ing SLOW LY by opening the control valve
station bypass valve in small increments.
10. With one of the control valve station block
valves still closed, and the loop controller
still in “man u al” mode, open bypass valve
and vary fl ow rate manually to observe the
re sponse of the controller and control valve
unit to geth er.
11. Attempt to develop manual control of the
loop by opening/closing the manual bypass
as required, or by manually controlling
main stream fl ow as required.
12. When the control valve is partially open,
crack open, slowly, the closed block valve
while si mul ta neous ly clos ing the bypass
valve; it may be necessary/desirable to vary
the man u al output SIG from the controller
si mul ta neous ly also. Continue this procedure until the by pass is closed and the block
valves are both fully open. The system is still
under “manual” mode control, but all fl ow is
passing thru the control valve.
CAUTION
DO NOT WALK AWAY AND LEAVE A MANUALLY
CONTROLLED CONTROL VALVE UNATTENDED!
13. Vary controller “manual” SIG output until
match ing the “automatic” SIG output, then
change the mode of the controller over to
“automatic”, and the loop will ex pe ri ence a
minimum of upset conditions, and will be in
automatic control.
IOM-5214
SECTION V
V. MAINTENANCE
WARNING
Model 521 control valves fre quent ly are installed
in haz ard ous/le thal fl uid ser vic es. Be fore re mov al
from pipe line or any level of dis as sem bly, con sult
the Own er’s safety pro ce dures for proper fl ushing,
clean ing and han dling of a valve ex posed to po ten tial ly haz ard ous fl uids dur ing de-pres sur iza tion
and re mov al. Owner's safe ty procedures pre empt
any state ments or rec om men da tions con tained in
this IOM.
A. General:
1. Once fl uid pressure has been iso lat ed by
block valves, and piping fl ange bolting has
been only loos ened, care ful ly re move vented
pipe plug (12) from the bonnet (2), applying
the detection procedures of C. 1. above, as
a small quantity of fl uid may be “trapped” in
the void space of the bellows (8) interior due
to permeation. The plug (12) has a “groove”
notched in its threads to assure venting prior
to the threads fully disengaging. Once fully
vented and/or purged as required by safety
procedures, reinstall the plug (12) using a
fl uid compatible lubricant . DO NOT USE
THREAD SEAL ANT FOR VENT ED PIPE
PLUG (12) ON RE IN STAL LA TION.
6. The stem sub-assembly (9) is designed
for non-rotation when installed. DO NOT
AT TEMPT TO RO TATE WITH THE STEM
SUB-ASSEMBLY IN STALLED; FAILURE
TO HEED MAY CAUSE DAMAGE TO THE
STEM SUB-ASSEMBLY (9), THE BELLOWS SUB-AS SEM BLY (8), THE PLUG
(3) AND/OR THE BODY ASSEMBLY(1).
Exhibit special care when handling the stem
(9) sur face where it contacts the packing
(6).
B. Pressure Boundary Leakage Shop Test:
1. Secure the body assembly (BA) in a vise
with the valve stem (9) oriented vertically.
2. Remove vented pipe plug (12).
3. Install a pipe nipple, test pressure gauge and
isolation valve into the 1/8"-NPT (female)
open ing. (See Figure 5.)
2. Maintenance procedures hereinafter are
based upon removal of the valve/actuator
unit from the pipeline where installed.
3. Owner should refer to Owner’s procedures
for re mov al, handling and cleaning of nonreuseable parts and suitable sol vents, etc.
4. Valves supplied from the factory do not use
any sealing aids for the gasket such as oil,
sealant, or pipe dope in the wetted portions
of the valve body as sem bly. Sealing aids
should not be required and are not rec om mend ed.
5. All indicated Item Numbers that are with
re spect to actuator assembly (AA) will be in
pa ren the sis and un der scored; i.e. (20). All
Item Num bers that are with respect to the
body assembly (BA) are not underscored;
i.e. (32). Reference with respect to the
positioner is in double parentheses; i.e.
((AP)).
Figure 5: Pressure Boundry Testing Confi guration
4. Place a suitable adhesive tape (“duct tape”)
around the perimeter of the bonnet/body
fl ange. Place tape on the “joint lines” of the
shell halves (1.1) (see Figure 10). Place blind
fl ang es over the fl anged end connections
and bolt down; one of the blind fl anges must
have a hole thru the face; place tape over
the opening of the blind fl ange.
5. Using a source of acceptable fl uid such as
ni tro gen gas, pressurize the bellows “void
zone” to 30 psig (2.1 Barg). Tightly close off
the isolation valve of 3. above. Disconnect
the pressure source.
6. Poke small holes in the tape at the bonnet/
body fl ange and at the opening in the blind
fl ange.
IOM-521
5
7. For units with Reverse Action (ATO-FC)
ac tu a tors pressurize to a level suffi cient to
initiate travel to approximately mid-stroke
to hold the plug (3) away from the body (1)
seat.
6. Loosen stem nut (20) by rotating nut CW
(viewed from above) to base of threads.
7. Loosen packing (6) by turning packing gland
nut (5) CCW 2-3 revolutions.
8. Apply leak detection fl uid to all the potential
leak paths:
a. Packing gland nut (5). (Tighten as nec es-
sary.)
b. Body (1)-to-bonnet (2) fl ange tape hole.
c. Body (1) and bonnet (2) bolting (13, 14,
1.3, 1.4, 1.5).
d. End connection blind fl ange tape hole.
e. Test pressure piping con nec tions.
9. If leakage occurs at:
a. a. above, there is a packing (6) or a pack-
ing (6) /stem sub-assembly (9) failure.
b. b. above, there is a bonnet gasket (11)
failure.
c. c. above, there is a bonnet gasket (11),
or TFE core (1.2) failure.
d. d. above, there is a bellows sub-as sem bly
(8) failure.
10. Following this test procedure may help
to solve main te nance problems when
combined with visual ex am i na tion of disassembled body assembly (BA).
8. Rotate yoke nut (15) CCW to fully loosen
nut.
9A. For ATO-FC Reverse Action Actuators:
a. Connect a temporary air source
to the actuator and pressurize the
actuator to upper limit of the bench
range specifi ed on the valve name
plate. (Pressure will lift the plug head
(3) away from the body's (1) integral
seat until the plug (3) is 100% open.)
b. Place a wrench on the hex surface of
the swivel lower knuckle (44) and rotate
knuckle CCW (viewed from above ac tu a tor) until lower knuckle dis-engages from
stem (9). Keep track of the number of
full rev o lu tions to dis-engage and record
here. _______________
c. Maintain lift support from above the
C. Separation of Body/Actuator:
1. Reference the Actuator IOM-C27-C53 for
item number call outs and drawings for
actuator.
2. Secure the body in a vise with the actuator
assembly (AA) oriented vertically. Place
matchmarks between the body (1) bon net
fl ange, the bonnet (2) fl ange, and the yoke
(3) to assist in fi nal ori en ta tion when the
body is dis as sem bled and/or the ac tu a tor
removed. If actuator has handwheel - see
Actuator IOM for removal instructions.
3. Secure and rig the actuator assembly (AA)
for a ver ti cal lift using an overhead hoist.
Remove slack from rigging.
4. This procedure assumes that the body as sem bly (BA) has been fully assembled thru
the bonnet (2), including the packing gland
nut (5) and packing (6).
5. Remove vented pipe plug (12) from body.
Figure 6: Swivel-Type Connector
actuator assembly (AA). Dis-engage
(slide) the swivel lower knuckle (44) out
of the upper knuckle (43) slot.
9B. For ATC-FO Direct Action Actuators:
a. Place a wrench on the hex surface of
the swivel lower knuckle (44) and rotate
knuckle CCW (viewed from above ac tu a tor) until lower knuckle dis-engages from
stem (9). Keep track of the number of
full rev o lu tions to dis-engage and record
here. ________________
b. Maintain lift support from above the
actuator assembly (AA). Dis-engage
(slide) the swivel lower knuckle (44) out
of the upper knuckle (43) slot.
IOM-5216
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