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1. Important Safety Procedures.
Qualified/Authorized
maintenance personnel should read and follow these straight forward
instructions.
- Always disconnect the air and
electrical supply before carrying out any form of maintenance on
an Actuator, also ensuring that the Air Chamber Reservoirs are
drained.
- Never attempt to remove Pistons
from the Actuator body by using air pressure when the End Caps
have been removed.
- Do not shorten or distort the
Safekeys:- correct
length Safekeys are supplied with the maintenance kit, it is
advisable to replace Safekeys during overhaul.
- When replacing items, use only
approved spares supplied by Hytork® or it's Stockist Distributors.
2.
Mounting And Operating Instructions
- 2.1. Actuator To Valve
Installation
- The mounting hole sizes and the
bolt hole circle are to ISO5211. These holes are ISO Metric
Course on metric models (UNC Course on imperial models) as
standard.
- When mounting the Actuator to a
valve using a Mounting Kit, the Pinion Drive, coupling device
and valve stem should be correctly aligned to prevent any side
loading to the bottom Pinion Radial Bearing and the Valve Stem
seal area.
- Ensure that the square coupling
shaft to be operated is a close, but free sliding fit into the
female drive in the Actuator Shaft.
- 2.2. Operating Pressures
- Minimum operating pressure that
the AFS800 should be operated on as a standard product is 3.5
bar (50 psi).
- The Maximum operating pressure
that the AFS800 can be operated on is 7 bar (100 psi).
- 2.3 Operating Media
- It is recommended that a clean,
dry, lubricated air supply be used. Other media's may also be
used, but consult your local Hytork®
Valve Automation Centre
for confirmation as to the suitability.
- The air supply should be
filtered to a minimum of 0.1 microns, filtration levels that do
not meet the minimum air filtration specification may adversely
affect the life expectancy of the Actuator.
- NB: If the site has a
lubricated air supply and the intention is to install a low
temperature AFS800 fitted with EPDM seals, the lubrication of
the air line must not use mineral oils. All other types of seals options that can be used on the
AFS800 will be unaffected by the use of mineral oil lubricants.
3. Piping instructions
- The AFS800 series of Actuators can
be connected to mains air with solid or flexible tubing See Fig.1
for additional information.
- Fig.1. Illustrates the AFS800 and denotes special piping
instructions.
4. Spares recommendations.
- When disassembling and carrying
out maintenance work on the AFS800, a Hytork® AFS800 Spares Kit
must be used to replace all 'O' ring seals,
Durastrip Bearing, thrust
washers etc. This Spares kit is available from Hytork® or it's
stockist Distributors.
Spares kits for the Control End Caps (one per unit) are not
available, however exchange End Cap Assemblies are available from
Hytork® or it's Stockist Distributors. See Section 1 for
Important Safety Instructions before starting.
5. Disassembly of AFS800 Actuator.
(See fig.1. For Actuator construction details)
- 5.1 Removal of End Cap/ chamber
assemblies.
NB: Always ensure that prior to disassembly, that both Air
Chambers have been fully vented (see fig.1. for location of vent
screws).
- Remove the End Cap balance pipe
(link pipe between Chambers) by the removal of the banjo bolt
located on the Dummy Chamber End Cap porting face and undoing
the union on the Control Chamber Porting Block.
- Undo the pipe unions of the pipe
fitted between the Solenoid Mounting Block and the Control
Chamber Porting Block.
- Unscrew the two fixing screws
holding the Solenoid Mounting Block.
- With the Solenoid Mounting Block
removed, remove the pipe that connects the Solenoid Mounting
Block and the Control Chamber Porting Block.
- Remove the Control Chamber
Porting Block by removal the three locating screws.
- Unscrew the two Safekeys located
in the Chambers, and gently pull to remove them from the
Chamber. If the Safekey tends to spring, then rotate the Chamber
slightly to assist release.
- When both Safekeys have been
removed, withdraw the Control and Dummy Chambers.
- Unscrew the two Safekeys
(cast identity letters C & D) located in the body next to
each End Cap, and gently pull to remove them from the body. If
the Safekey tends to spring, then rotate the End Cap slightly to
assist release.
- When both Safekeys have been
removed, withdraw the Control and Dummy End Caps. Stripping
of the control End Cap for overhauling of the internal valve is
not recommended (due to the test procedures required), exchange
Control End Caps are available from Hytork® and it's Stockists
Distributors
- 5.2 Removal of Pistons.
- With both End Caps removed,
rotate the Pinion using a wrench (spanner) to drive the Pistons
apart until the Pinion rotates freely, indicating total
disengagement of Pistons to Pinion.
Insert a M16 screw into the Piston extraction hole located in
the Piston head, using the extraction bolt rotate the Pistons in
the Actuator body approximately 10°.
Rotate the Pinion using minimum force and the Pistons will push
free of the Actuator body, Carefully supporting the Piston,
extract the Pistons from the Actuator main bore.
- 5.3 Removal of Pinion.
- Remove the Snap Ring (Circlip),
Steel Thrust Washer and Thrust Bearing from the top of the
Pinion and carefully remove the Pinion from the cylinder body.
Care must be taken to ensure that no damage is cause to the
Pinion or Pinion cross Bores during the removal of the Pinion.
If necessary remove any burrs/site damage marks, etc. from the
top of the Pinion before removing it.
- 5.4 Inspection.
- Clean and inspect all parts for
damage and wear.
6. Assembly instructions.
- IMPORTANT: ALL Hytork®
AFS800 Spares Kits are supplied with Safekey Assemblies cut to an
exact length which will fit the circumference of the End Caps and
Chambers when fully assembled into the Actuator. Any shortened
Safekeys must not be used.
If in doubt contact Hytork® or your local Stockist Distributor.
- 6.1 Inspection.
- Check that all components are
clean and free from damage.
HYTORK® recommend that all 'O' rings, bearing strips, washers,
etc. are replaced using only a HYTORK® AFS800 Series Spares kit.
- 6.2 Installing the Pinion.
- Lightly grease the Pinion with
Lithium Based Grease (Subject to Actuator temperature
specification), ensuring that grease is applied to the 'O' ring
and Bearing Strip Grooves of the Pinion.
Install one steel Thrust Washer over the top of the Pinion and
slide it down to the top of the gear form. Take the top Pinion
Durastrip Radial Bearing and fit it into the top Pinion location
groove, slide one of the Durastrip Thrust Bearing Washers down
over the Radial Bearing Strip, this will now hold the Radial
Bearing in the correct position for assembly.
Fit the top 'O' ring into the Pinion groove. Fit the bottom
radial strip into the bottom Pinion location groove and hold in
position using the bottom 'O' ring. Lightly grease the Pinion
bores of the body before assembly. Carefully insert the Pinion
into the body until the top of the Pinion rests in the top bore
but the bottom Radial Bearing Strip groove is still protruding
from the bottom of the Actuator. Gently slide the Pinion up
through the body making sure that the ends of the bottom Bearing
Strip are not trapped and the 'O' ring slides or rolls into the
'O' ring groove as the Pinion is pushed home into the body.
With the Pinion in this position, install the outer Durastrip
Thrust Washer, followed by the Steel Washer.
Finally to secure the Pinion fit the Snap Ring into the narrow
groove in the top of the Pinion (making sure that the Snap Ring
locates properly in the groove).
- Standard Mode Of Operation.
This mode is used for most Fail Closed situation.
Clockwise rotation of the pinion will draw the pistons together.
(Closed Position.)
7. Alignment of Pinion for correct
Piston installation.
- 7.1 (Refer to fig.2.) To install the Pistons for
standard Air Fail Closed operation, proceed as follows:
- Rotate the Pinion so that the dot on the top of the Pinion
is positioned close to the single dot on the Actuator body.
Accurate Pinion alignment can now take place by lining up the
centre of the slot on the top of the Pinion with the centre of
the single dot on the body.
- 7.1 Installation of the Pistons
(See fig.2.).
- Before attempting to fit the
Piston Durastrip Bearings, bend the locating tangs outwards so
that location of the strip is unhindered.
- Ensure that the dovetail on the
Bearing Strip is correctly aligned to the dovetail grooves
machined into the Piston.
- With the Bearing strip tang
facing away from the Piston head, push the Bearing strip into
the dovetail groove, until the tang is located on the centre
line of the Piston.
- The tang must now be pushed into
the retaining slot on the Piston, once completed lightly grease
the Piston 'O' rings with Lithium base grease (Subject to
Actuator Temp specification).
- Liberally grease the Actuator
main bore and the Pistons using Lithium based grease and fit 'O'
rings into the 'O' ring groove of the Pistons.
- Insert the Pistons into the
bore, one Piston in each end with the teeth facing each other,
to ensure that the Piston racks lines up with the Pinion gear.
The alignment groove in the front face of the Piston must be
lined up parallel to the Pinion and the 'gun sights' cast in the
body.
- Push both Pistons together until
they are both in contact with the Pinion, so that when the
Pinion is rotated clockwise (see fig.2.) the Pistons are drawn
together. When the Pistons are together and the Racks are
correctly engaged with the Pinion, the top Pinion drive flats
should be at right angles to the axis of the body (assuming the
Actuator has been fitted with Standard Pistons).
- NB: Actuator can be
fitted with 'A' style Piston which will allow for 3° under and
over travel, however this will require the fitting of Bottom
Mounted Stop Block, operating/installation instructions for the
Bottom Mounted Stop Block
can be obtained from Hytork® or it's Stockist Distributors.
8. Reverse Action Mode Of Operation.
- This mode is used for most fail open
situations. Anticlockwise rotation of the pinion and pistons
moving towards each other.
- Alignment of Pinion for correct Piston
installation. (Refer to fig.3.)
- To install the Pistons for standard Air
Fail Open operation, proceed as follows.
- Rotate the Pinion so that the dot on the
top of the Pinion is positioned close to the three dots on the
Actuator body.
- Accurate Pinion alignment can now take
place by lining up the centre of the slot on the top of the
Pinion with the three dots on the body.
- 8.1 Installation of the Pistons. (See
fig.3.)
- Assemble Bearing strips and 'O' Rings and
grease as described in section 7.1.
- Insert the Pistons into the bore, one
Piston in each end with the teeth facing each other as shown in
fig.3.
- The alignment groove in the front face of
the Piston must be lined up parallel to the Pinion and the 'gun
sights' cast in the body.
- Push both Pistons together until they are
both in contact with the Pinion, so that when the Pinion is
rotated anti-clockwise (see fig.3) the Pistons are drawn
together. When the Pistons are together and the racks are
correctly engaged with the Pinion, the top Pinion drive flats
should now be approximately parallel to the axis of the body
(assuming the Actuator has been fitted with Standard Pistons).
NB: Actuator can be fitted with 'A' style Piston which
will allow for 3° under and over travel, however this will
require the fitting of Bottom Mounted Stop Block,
operating/installation instructions for the Bottom Mounted Stop
Block can be obtained from HYTORK® or it's Stockist Distributors.
- 8.2 Installing the End Caps.
- Install the 'O' Ring seals to the slotted
screws of the Chamber End Cap Safekeys.
- Lightly grease the End Cap 'O' Rings with
Lithium based grease (Subject to Actuator temp specification).
- Grease the ends of the body bore and the
Chamber End Caps making sure that the grease goes into the
grooves.
- Install the 'O' Ring into the square
bottomed groove in the Chamber End Cap and insert the Cap into
the body.
- Ensure that the port entries are on the
same side as the Namur Pad and the alignment groove on the
Chamber End Cap top cast faces are lined up parallel to the 'gun
sights' cast in the body.
- Holding the Safekey close to the entry
hole to prevent kinking, insert the Safekey into the hole and
gently push into place, before finally tightening.
- Pipe Actuator in accordance in reverse
order of section 5.1 (as shown in fig.1.).
- 8.3 Installing the Chambers.
- Install the 'O' Ring seals to the Chamber
Safekeys.
- Lightly grease the external Chamber End
Cap 'O' Rings with Lithium based grease (Subject to Actuator
temp specification).
- Grease the Chamber End Cap and the
Chamber seal areas, making sure that the grease goes into the
grooves.
- Install the 'O' Ring into the square
bottomed groove in the Chamber End Cap and fit the Chamber onto
the End Caps.
- Ensure that the cast in text is located
at the bottom of the castings and that correct alignment of the
Chambers is achieved by aligning the marks on the Chamber End
Cap and Chamber to coincide.
- Holding the Safekey close to the entry
hole to prevent kinking, insert the Safekey into the hole and
gently push into place, before finally tightening.
9. Testing the HYTORK® Actuator (No Solenoid
Valve or Positioner fitted)
After overhaul of the Actuator the following
test measures should be carried out to confirm correct functioning
of the Actuator.
- Requirements.
- 2 x regulated 1/2" air supply lines.
- Mixture of Tepol and water or an
equivalent detergent solution.
- Brush.
- Control Chamber Testing. (see Fig.4.).
- Connect a 1/2" air supply via a 0-100 psi
regulator to the Chamber porting block with the pressure
regulator set to zero (ensure that both Chamber vent plugs are
fully tightened See Fig.1.).
- Increase the supply line pressure in to
20 psi and allow chamber to fully charge, incrementally increase
the supply pressure to the Chamber by 5 psi until such time as
the Actuator exhausts out of the Closing port of the Actuator
(>S<).
- If the Actuator fails to exhaust from the
closing port before a pressure of 35 psi has been reached or
continues to exhaust for an extended period of time, a further
inspection will be required on the internal valve contained
within the Control Chamber.
- Once the Chamber Valve has exhausted
increase the supply pressure to not less than 50 psi and not
higher than 100 psi (the Chambers are now isolated from the
Actuator and will only be required to function in the event of
loss of supply pressure).
- Function Testing Of Actuator. (see Fig.4.).
- Connect a second 1/2" air supply,
regulated to not less than 50 psi and not more than 100 psi to
the closing port
- Once the pressure has stabilised, apply
the selected leak testing solution to the End Caps and Chambers
paying particular attention to joint lines, Chamber porting
block and Safekey seals.
- Using a brush and the soap solution, form
a bubble over the opening port of the Actuator. Once a bubble is
formed, any growth would indicate that air is escaping past the
Piston 'O' rings.
- If no leaks are found disconnect the air
supply from the closing port and re-connect to the Actuator
opening port.
The Actuator will now open, leak testing of the centre chamber
of the actuator should be performed paying particular attention
to the Pinion top and bottom 'O' ring seal areas.
- Using a brush and the soap solution, form
a bubble over the opening port of the Actuator. Once a bubble is
formed, any growth would indicate that air is escaping past the
Piston 'O' rings.
- If no leaks are found remove the
regulated air supply from the opening port of the Actuator
- Failure Mode Function Testing Of The
Actuator. (see Fig.4.).
- To ensure that the Actuator will function
in event of air loss remove the air supply from the Chamber
porting block, the Actuator should now close in approximately 9
seconds (no load applied).
Fig.4. Illustration of AFS800 test
ports
Sketch to aid in component
recognition of AFS800.
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