Flowserve NAF Duball DL User Instructions

NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

USER INSTRUCTIONS

NAF Duball DL Pocket Valve

FCD NFENIM4163-00-A4 05/17

Installation

Operation

Maintenance

Experience In Motion

1

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NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

Contents

SAFETY 2
1 General 2
2 Lifting 3
3 Receiving Inspection 3
4 Installation 3
5 Operating sequence 4
6 Commissioning 6
7 Operation 6
8 Bill of Materials and recommended spare part kits 7
9 Ordering of spare parts 8
10 Maintenance 8

10.1 Removing the valve from the pipework 8

10.2 Disassembling the valve for inspection and replacement of ball,
seats and stem packing 8

10.3 Reassembly of the valve 9

10.4 Replacing seat rings 9

10.5 Replacing the Pocket ball 10

10.6 Replacing the stem packing 10
11 Fitting an actuator to the Pocket Valve 11

SAFETY

• Assess all risks to eliminate the possibility of personal
injury and material damage. Read these instructions
thoroughly.

•

Always use the necessary protective equipment and comply
with applicable safety direc
hazardous or hot/cold media.

• Never operate a valve without first ensuring there is no risk
of crush injuries. The risk is highest with automated valves.
Take necessary safety precautions to avoid unintentional
stroking of the actuator / valve.

• Never dismantle a valve or part of a valve without ensuring
the line is free of pressure and media.

•

Ball valves must always be dismantled in the semi-open
position to avoid trapping pres

2

• Always check that the valve type and material is suitable for
its intended use. This applies especially to highly oxidizing
and corrosive media. Observe also the risk of erosion or

explosion, as well as decaying medium. If in doubt, always
request a written recommen

tives when working with

sure and media.

dation from Flowserve.

1 General

This instruction provides necessary information for the correct
handling of the NAF Duball DL Pocket Valve. For additional equipment
used together with the valve, please refer to their corresponding
instructions.

If you have any doubt about the correct use and handling of a specific
version of NAF Duball DL Pocket Valve, please contact your Flowserve
representative.

The instructions and list of spare parts in this document are applicable
to the NAF Duball DL Pocket Valve in accordance with our Technical
Bulletin NFENTB4163.

As the NAF Duball DL Pocket Valve is a special applications valve,
special terms and conditions may apply. Please refer to specific
purchase.

NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

2 Lifting

All lifting must be carried out on the valve itself and not on the
actuator. The mounting connection between the valve and the actuator
is designed principally for carrying the operating torque and the
deadweight of the actuator and is not designed to support the weight
of the valve. See Figure 1.

4 Installation

Before installing the valve, please ensure that:

• The pipework is free from impurities

• The pipe end connectors between which the valve is to be installed are
parallel and are correctly aligned

• The distance between the pipe ends correspond to the valve length,
including gaskets.

The valve must not be used for pulling together or aligning incorrectly run
pipes as this will cause improper loads on the valve and pipe which could
lead to severe problems during operation. See Figure 2.

Incorrect installation

Correct installation

Figure 1: Schematic lifting of a valve with mounted actuator. Note that
the final lifting of the valve into a vertical pipe requires different lifting
points.

3 Receiving Inspection

All valves leaving our facility are inspected and tested in accordance
with the relevant requirements or in accordance with the special
provisions specified by the purchaser. Valves equipped with actuators
are subjected to functional testing and are adjusted in such a manner
that every unit is ready for direct installation in the pipework. However,
NAF always recommend that a receiving inspection is to be carried out.

We suggest the following inspection procedure:

• Check that the valve delivered is correct in terms of type, size,
equipment, etc.

• Examine the valve, actuator and valve positioner for possible damage
that may have occurred during transport.

Figure 2: Ensure that the pipe ends align and have the correct gap

A typical application for the NAF Duball DL Pocket Valve is when it’s installed
in the reject pipe of a sand separator. See Figure 3. Make sure that the valve
is mounted in the correct flow direction as indicated by the flow arrow on
the valve body.

NAF strongly recommend that a Duball DL valve is installed upstream of
the Pocket Valve. This valve is to be open in normal operation and only shut
when the Pocket Valve is to be inspected/serviced.

If not supplied by NAF, two on/off valves should be installed on each of
the flush connections (1 & 2 as shown in Fig. 3) in close proximity to the
Pocket Valve. The Pocket Valve and the on/off valves should be operated as
described in Section 5, “Operating sequence”.

The pipes should be supported on each side of the valve in order to
relieve the valve of unnecessary loads and avoid vibrations.

The actuator used on the Pocket Valve should be supported in order
not to introduce unnecessary loads and to minimize any potential
influence from vibration.

Locate the valve so it will be easily accessible for inspection and
service.

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Outlet with

liquor

NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

Inlet with liquor

Duball DL
ball valve

Body flushing

connection 1

Figure 3: Mounting of the Pocket Valve in a Sand Separator application

5 Operating sequence

The NAF Duball DL Pocket Valve is operated by the following sequence:

1. The Pocket Valve is in “Filling mode”. Sand/debris is collected in the
Pocket ball.

2. When the Pocket ball volume is approximately 50% full (volumes for
the different sizes can be seen in Table 1) the “Discharge sequence”
(emptying) is initiated and CCW (counterclockwise) rotation of the
Pocket ball starts. Connection 1 is set to “ON” (open) and body flushing
starts. This flushing inhibits sand/debris to be collected in the body of
the Pocket Valve. Body flushing at connection 1 should remain “ON”
until the Pocket Ball has completed a full discharge sequence.

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3. CCW rotation continues from 0 to 140 degrees.

4. Final Discharge position is reached at 140° and rotation stops.
Connection 2 is set to “ON” (open) and ball flushing starts. It is

Pocket valve

Ball flushing
connection 2

Drain/mud/sand

recommended that the Pocket ball remains in this position for at least
10 seconds. However, due to the nature of the debris in the Pocket ball,
a longer flushing may be needed.

5. Discharging is completed and connection 2 is set to “OFF” (close) and
ball flushing stops. The Pocket ball starts CW (clockwise) rotation back
to the open/fill position.

6. CW rotation continues from 140 to 0 degrees.

7. The “Discharging sequence” is now completed and rotation stops. Body
flushing from connection 1 is set to “OFF” (close) and stops. The valve
is now back in “filling mode”.

A schematic figure of the operating sequence can be seen in Figure 4.

NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

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mode”.

is now back in “filling

Discharging sequence

completed - The valve

12

continues

CW rotation

12

Discharge is

rotation starts

completed - CW

5 - 15 seconds

(not controlled, depending on air capacity etc.)

12

minimum 10 seconds

rotation stops

Final discharge

position is reached -

12

continues

CCW rotation

12

rotation

starts with CCW

Discharge sequence

12

5 - 15 seconds

Figure 4: Schematic figure of the Pocket Valve operating sequence

(not controlled, depending on air capacity etc.)

Sequence no. 1 2 3 4 5 6 7

mode

Filling

Sequence

description.

0°

140°

Valve position

On

Off

Body flushing

(connection 1)

On

Off

Ball flushing

(connection 2)

10 minutes (typical)

Timeline

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6 Commissioning

NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

Before starting up, flush the pipework and run a discharge sequence,
assuming the sequence is set according to “Operating sequence”
above. This allows any impurities that may damage the sealing
surfaces of the valve or impede its operation to be flushed away.

7 Operation

The NAF Duball DL Pocket Valve is installed to safely remove sand/
debris out of the process as effectively as possible while maintaining
process pressure.

It is of great importance that the number of discharging sequences of
the Pocket Valve is adjusted to the process where the valve is installed.
Over-filling of the Pocket Valve can cause excessive wear and signifi­cantly shorten the life time of the valve. However, excessive operation
of the Pocket Valve causes wear to both stem and actuator.

The volume of the Pocket ball cavity can be seen in Table 1. The
volume of the ball, together with the expected volume of sand/debris
to be removed from the process can be used to calculate the suitable
size of the valve. We recommend that a Pocket Valve should not be
calculated to operate more than 5 times per hour using 50% of the
total volume of Pocket ball. This will give some marginal for not over­filling the valve due to process variations. At the same time the number
of discharge cycles will be not be excessive, creating unnecessary
wear of the valve.

Example: The process has an expected need of removing 10 liters of
sand per hour. This means that each discharging sequence must be
able to remove 10/5=2 liters per sequence. Based on only using 50%
of the ball cavity volume per sequence, at least 4 liters of cavity is
needed. The correct size will therefore be a DN200/8” Pocket Valve.

Valve size Pocket ball cavity volume (liters)

DN80/3” 0,44

DN100/4” 0,82

DN150/6” 2,76

DN200/8” 6,86

Table 1: The total volume of the Pocket ball cavity

When the Pocket Valve is taken into operation, it is recommended that
the emptying frequency is set to 3 minutes, i.e. the Pocket Valve is in
the filling position for 3 minutes followed by a discharge sequence.
Once the process is stable, commence with measurements to adjust
the sequence time to allow the Pocket ball to be 50% full by volume. If
sand/debris content varies with time/product, please adjust sequences
time to reach the recommended 50% filling of the Pocket ball.

NOTE: After adjusting the cycle time as per above, the needed number
of discharge sequences exceeds 8 per hour, it must be considered to
replace the valve with a bigger size. Exceeding 8 discharge sequences
per hour will result in an increased need for maintenance and a
significantly higher risk of failure. More than 12 discharge sequences
per hour is not at all recommended and must be avoided.

The water pressure in connection 1 and connection 2 must exceed
inlet pressure by at least 500 kPa during the entire flushing sequence,
to ensure that water is flushed into the valve body and Pocket ball is
cleaned correctly.

The NAF Duball DL Pocket Valve normally operates with an actuator
with travel stops set to 140°. During operation, the valve should rotate
counterclockwise (CCW) to the discharge position and clockwise (CW)
when returning to the filling position. NAF do not recommend running
the valve with a 360° actuator as full rotation may cause additional
wear to the Pocket ball and seat rings.

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NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

8 Bill of Materials and recommended spare part kits

19

12

11

10

9

8

7

6

16

5 20

Figure 5: Exploded view with item/part numbering

13

2

3

4

15

21

14

1

18

17

22

23

Item Qty Part

1 1 Body, main

2 1 Body, cover

3 1 Pocket Ball X

4 2 Seat ring X

5 1 Stem

6 1 Circlip X

7 1 Cover

8 1 Spring X

9 1 Washer X

10 1 Stem packing X

11 1 Washer X

12 1 Bushing X

1)

Quantity depending on size of the valve.

Version is determined by NAF No. on the identification plate of the valve.

Kit A

Table 2: Bill of Materials and Recommended Spare Parts Kits

Kit D

Stem sealing kit

Material and design of the parts vary depending on the version of the valve.

Kit E

Seat and ball kit

Seat seal kit

Item Qty Part

13 1 Anti-friction Washer X

14 1 Body seal X

15 2 Inside seat seal X

16

17 2 Stud

18

19

20 2 Key

21 2 Outside seat seal X

22 2 Seal ring

23 2 Water flushing fittings

1)

1)

1)

Screw

Bolt

Nut

Kit A

Kit D

Stem sealing kit

Seat and ball kit

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Kit E

Seat seal kit

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NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

9 Ordering of spare parts

We recommend that a spare valve is always available for the majority
of applications where the Pocket Valve is used. This is based on the
fact that wear can be significant and a regular maintenance need will
occur over time. Having another valve available will minimize the
process downtime.

When placing an order for spare parts, specify:

• NAF-No: specified on the identification plate of the valve.

• Recommended spare part kit according to Section 8.

• Quantity required.

Ordering example:

NAF-No: 8883KF-0200-BBAHEA-P

Spare part kit: A

Quantity: 1 pc

Caution. Liquid in the valve may be harmful.

5. Release the flanged joint between the valve and the pipework.

Then lift out the valve. Don’t use the actuator for lifting. Apply
all lifting forces to the valve itself and not to the actuator. See
Figure 1.

10.2 Disassembling the valve for inspection

and replacement of ball, seats and
stem packing

For part numbers, see Figure 5. For spare part kits, refer to Table 2.

1. The actuator does not need to be removed for replacing the

seat rings and ball. However if the stem seal is leaking, the stem
packing must be replaced. Even if the stem seal does not leak,
we always recommend replacing the stem packing and body
seal every time the valve is disassembled. This preventative
maintenance will avoid unnecessary extra work and downtime
caused by leakage in the future. We always recommend the use
of a stem sealing kit, spare part kit A. For further instructions on
replacing the stem packing, please see Section 10.6.

10 Maintenance

Many valves are installed in locations where their performance is
of critical importance to the entire process. Such valves should be
inspected regularly and any issues should immediately be corrected.
As the NAF Duball DL Pocket Valve is used in high wear and high cycle
applications, we highly recommend that an inspection is performed
regularly. If the valve is in need of service, schedule maintenance as
soon as possible and make sure that necessary spare part kits are
available.

10.1Removing the valve from the pipework

The procedure for inspection and maintenance requires no special
tools.

Ensure the process line is shut off, free of pressure and

drained of media.

1. Ensure that the recommended spare parts and gaskets for the
pipe flanges are available.

2. Before removing the valve from the pipeline, operate it several
times between the open and closed position to ensure that any

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trapped media / pressure is released.

3. Shut off all compressed air connections and isolate all electrical
connections to the actuator.

2. Operate the valve to make certain that it is completely empty
of process media.

3. Put the valve on a suitable, flat surface with the body cover (2)
facing upwards. Remove the body cover (2).

4. Remove the ball (3), which is done when the ball is in the
position shown in Figure 6. Secure the ball (3), inhibiting it from
moving/rolling.

5. Clean all parts thoroughly. First use hot water and then, if neces­sary, degreasing agent. Do not scrape any of the machined
surfaces with hard tools.

6. Carefully inspect parts individually and replace parts as per
descriptions below.

4. Disconnect all compressed air lines and electric cables
connected to the actuator.

Figure 6. Lifting the ball

10.3 Reassembly of the valve

To replace parts, see sections 10.4-10.6 below. After the inspection
and/or part replacements have been made, reassemble the valve as
described below. For part numbers, see Figure 5. For spare part kits,

refer to Table 2.

1. If the Pocket ball has been lapped with the seat rings, it is of

great importance that the Pocket ball and seat rings are cleaned
before being assembled in the valve body. Use a suitable solvent
and carefully clean the lapping paste from the Pocket ball and
seat rings. Make sure that no lapping paste remains.

2. Grease the seat rings (4) with Klüber Barrierta L55/3 grease (or

similar). The coat of grease must be thin and evenly distributed.

3. Fit the body seal (14) between the two halves (1, 2) of the body.

It is always recommended to use a new body seal from the
stem seal kit.

4. Fit the ball (3) in the main body (1). See Figure 4. Then fit the

body cover (2). Note: The main body (1) and body cover (2) will
only fit in one position.

5. Check that the Pocket ball opening is facing upwards in the

direction of the body cover (2). If not, turn the ball 180 degrees.

NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

10. There should be a small gap between the Pocket ball and the
seat ring to get the correct torque while restricting big particles
from entering the body. Inspect that the gap between the Pocket
ball (3) and seat ring (4) is correct by moving the Pocket ball to
approximately 45°. The gap between the Pocket ball and seat
ring should measure approx. 0.2-0.3 mm.

11. If possible, pressure test the valve with water to check its tight­ness after reassembly. Testing should be done when the Pocket
ball is in filling position. If the valve has been pressure tested,
please check and, if needed, re-tighten the bolts according to
step 3 above.

Testing with the use of gaseous media is not recommended

due to safety issues. Testing the valve body tightness should
not be performed at a pressure higher than 1.5 x maximum
allowed working pressure. Refer to Technical Bulletin
NFENTB4163. Due to the floating action of the ball, the ball
needs a certain volumetric flow to effectively seal the ball
against the seat. We recommend for valve sizes DN150/6”
and larger, that the inlet pipe connection is a minimum of 25
mm/1”.

6. Lubricate all studs/bolts (17, 18) with suitable anti-galling
grease.

7. Lubricate the contact surface of the nuts (19) with a suitable
anti-galling grease and put the nuts onto the studs/bolts (17,

18). Start to tighten the bolted joint of the two body halves
(1, 2) of the body alternately in several stages in a diagonal
sequence. Make sure that the body seal (14) remains in its
designated position.

8. Inspect that there is no visible gap between the body halves and
finally tighten according to the torque in accordance with Table 3

Bolt Torque Nm Bolt Torque Nm

UNC ½” 89 M12 76

5

UNC

/8” 175 M16 187

UNC ¾” 308 M20 364

7

UNC

/8” 493 M24 629

UNC 1” 737

Table 3. Required torque for the bolted joint of the two body halves

9. Operate the valve between the closed and open positions.

10.4 Replacing seat rings

To remove the locket seat rings, use a suitable precision power tool
with a cutting blade (or similar equipment) to carefully remove the
lockings from the seat ring without further damaging the seat ring.

To ensure tightness of the valve, fit new seat rings (4) if the original
ones are severely worn or damaged.

Visually inspect the sealing surfaces of the seat rings (4). A groove on
the inside diameter of the seat facilitates the removal of the seat ring.
Minor damage to the seats can be rubbed down with fine emery cloth.

.

Check the seats on a face plate to ensure that they are perfectly flat.
Change the seats if they are severely worn or damaged.

The ball (3) and seat rings (4) can be temporarily overhauled by
lapping them together. This can be done manually with a compound
with grit size 200. Take great care to ensure that the ball and seat rings
do not become oval.

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Figure 7. Venting using a feeler gauge

Figure 8. Locking the seat rings into place

NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

Inspect the ball (3) visually. Minor damage to the sealing surface can
be removed by rubbing down with fine emery cloth. If the ball has
sustained major damage, it must be replaced to ensure satisfactory
sealing.

The ball (3) and seat rings (4) can be temporarily overhauled by lapping
them together. This can be done manually with a compound with grit
size 200. Take great care to ensure that the ball and seat rings do not
become oval.

If the sealing areas on the Pocket ball are damaged, we recommend
that the valve is returned to Flowserve for overhaul. This applies in
particular if the ball must be reground before lapping. Assemble the
valve before dispatching it to Flowserve NAF.

10.6 Replacing the stem packing

New seat rings (4) can be supplied that have been grounded and
lapped together with a ”Master-ball”. Some additional machining of
the rear side of the rings may be necessary in order to optimize fit.
However, NAF always recommended to order a complete Ball kit D to
ensure best possible tightness and sealing effect. Please refer to table
2 for spare part kits.

The Pocket Valve is equipped with seat rings with an outside and
one inside seats seal (21,15). Furthermore, the seat rings are locked
mechanically in place.

1. Fit the outside seat seal (21) and the inside seat seal (15) onto
one of the seat rings (4). Use some silicone grease. Repeat for
the other seat ring (4).

2. Gently push the seat ring (4), including the outside and inside
seat seal (21, 15), into the seat area. During the assembly, the
seat ring seals (o-rings) need to be vented. The easiest way to
do this is to use a feeler gauge. See Figure 7. Place the feeler
gauge at the outside location where there is a small flat surface
on the outside of the seat ring (4).

3. After seat rings have been vented and fitted properly, they are
to be locked in position. Push the seat ring down into the body
and lock the seat rings in accordance with Figure 8. Locking
should be done in equally the same number of locations as the
original locking. It’s important that the locking is done thor­oughly in order to make sure the seat rings are properly fixed.

If the stem seal is leaking, the stem packing must be replaced. Even
if the stem seal does not leak, we always recommend replacing the
stem packing every time the valve is disassembled. This will prevent
unnecessary extra work and downtime caused by a stem leakage in the
future. We always recommend the use of a stem sealing kit, spare part
kit A.

Make sure that the valve is not under pressure.

1 Remove the actuator.

2 Remove the keys (20).

3 Remove the circlip (6), back off the screws (16), and remove the

cover (7) and the spring (8).

4 Disassemble the valve as described in section 10.2.

5 Press the stem (5) down into the body and remove it.

6 Press the bushing (12) down into the body and remove it.

7 Remove the stem packing (10) and washers (9) and (11). See

Figure 9.

8 Fit a new anti-friction washer (13) to the stem (5) followed by a

new bushing (12). Then fit the stem assembly (5, 12, 13) into
the valve body.

9 Fit washer (11) and a new stem packing (10) using a suitable

silicon grease.

10.5 Replacing the Pocket ball

10

Due to the application, it is of great importance to routinely inspect
the status of the Pocket ball. Wear and damage to the ball will not only
increase risk of leakage but also likely increase needed torque risking
damaging the valve body, stem and actuator.

10 Fit washer (9) and spring (8).

11 Fit cover (7) and tighten the screws (16) alternately in several

stages.

12 Fit the circlip (6).

5

20

6

16

7

8

9

10

NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

11

12

13

Figure 9.Stem packing

13 Assemble and, if possible, pressure test, the valve as described

in Section 10.3. However, first assess whether the seat rings (4)
and pocket ball (3) should be replaced.

11 Fitting an actuator to the Pocket
Valve

1 Fit the actuator to the valve. Ensure that the valve is in the filling

position and that the actuator is in the closed position before
fitting the actuator. Standing the main body (1) on a flat surface,
the valve is in the filling position when the keys (20) in the stem
(5) are perpendicular to the valve flow path and the ball opening
is facing upwards in the direction of the body cover (2).

2 Check the operation and check that the end stops have been

correctly preset or adjust them so the ball is in the correct
position.

Note: The direction of discharge must always be counterclock-

wise (CCW) as viewed from the actuator. Accordingly, returning
to the filling position should always be in the clockwise (CW)
direction.

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NAF Duball DL Ball Valves NFENIM4163-00-A4 05/17

NAF AB

SE-581 87 Linköping

Sweden

Telephone: [phone]
Facsimile: [phone]
e-mail: salesnaf@flowserve.com
Website: www.flowserve.com
www.naf.se

NFENIM4163-00-A4 05/17

To find your local Flowserve representative

or for more information about Flowserve Corporation, visit
www.flowserve.com.

Flowserve Corporation has established industry leadership in the design and manufacture of its products. When properly
selected, this Flowserve product is designed to perform its intended function safely during its useful life. However, the purchaser
or user of Flowserve products should be aware that Flowserve products might be used in numerous applications under a wide
variety of industrial service conditions. Although Flowserve can (and often does) provide general guidelines, it cannot provide
specific data and warnings for all possible applications. The purchaser/user must therefore assume the ultimate responsibility for
the proper sizing and selection, installation, operation, and maintenance of Flowserve products. The purchaser/user should read
and understand the Installation Operation Maintenance (IOM) instructions included with the product, and train its employees and
contractors in the safe use of Flowserve products in connection with the specific application.

While the information and specifications contained in this literature are believed to be accurate, they are supplied for informative
purposes only and should not be considered certified or as a guarantee of satisfactory results by reliance thereon. Nothing con­tained herein is to be construed as a warranty or guarantee, express or implied, regarding any matter with respect to this product.
Because Flowserve is continually improving and upgrading its product design, the specifications, dimensions and information
contained herein are subject to change without notice. Should any question arise concerning these provisions, the purchaser/user
should contact Flowserve Corporation at any one of its worldwide operations or offices.

© 2017 Flowserve Corporation, Irving, Texas, USA. Flowserve is a registered trademark of Flowserve Corporation.

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