TLV COSR-3 User manual

172-65174MA-11 (COSR Pressure Reducing Valve) 16 February 2022
Pressure Reducing Valve for Steam
COSR-3/COSR-16/COSR-21
Copyright © 2022 by TLV CO., LTD.
All rights reserved

172-65174MA-11 (COSR Pressure Reducing Valve) 16 Feb 2022
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Contents
Introduction ........................................................................ 1
Safety Considerations........................................................ 2
Specifications..................................................................... 4
Acceptable Operating Range............................................. 4
Correct Usage of the COSR Pressure Reducing Valve..... 5
Configuration...................................................................... 7
Installation........................................................................ 11
Adjustment ....................................................................... 16
Maintenance..................................................................... 17
Disassembly..................................................................... 18
Reassembly ..................................................................... 23
Troubleshooting ............................................................... 24
TLV EXPRESS LIMITED WARRANTY............................ 26
Service ............................................................................. 28
Introduction
Thank you for purchasing the TLV COSR pressure reducing valve for steam.
This product has been thoroughly inspected before being shipped from the
factory. When the product is delivered, before doing anything else, check the
specifications and external appearance to make sure nothing is out of the
ordinary. Also be sure to read this manual carefully before use and follow the
instructions to be sure of using the product properly.
The TLV pressure reducing valve for steam, model COSR provides a more
stable secondary pressure than conventional reducing valves. The COSR is
designed for long service life, with all major components made of stainless
steel for superior durability.
If detailed instructions for special order specifications or options not contained
in this manual are required, please contact TLV for full details.
This instruction manual is intended for use with the model(s) listed on the front
cover. It is needed not only for installation, but also for subsequent
maintenance, disassembly/reassembly and troubleshooting. Please keep it in a
safe place for future reference.

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Safety Considerations
Read this section carefully before use and be sure to follow the instructions.
Installation, inspection, maintenance, repairs, disassembly, adjustment and valve
opening/closing should be carried out only by trained maintenance personnel.
The precautions listed in this manual are designed to ensure safety and prevent
equipment damage and personal injury. For situations that may occur as a result of
erroneous handling, three different types of cautionary items are used to indicate
the degree of urgency and the scale of potential damage and danger: DANGER,
WARNING and CAUTION.
The three types of cautionary items above are very important for safety: be sure to
observe all of them as they relate to installation, use, maintenance, and repair.
Furthermore, TLV accepts no responsibility for any accidents or damage occurring
as a result of failure to observe these precautions.
Symbols
Indicates a DANGER, WARNING or CAUTION item.
Indicates an urgent situation which poses a threat of death or serious
injury
Indicates that there is a potential threat of death or serious injury
Indicates that there is a possibility of injury or equipment/product
damage
Install properly and DO NOT use this product outside the
recommended operating pressure, temperature and other
specification ranges.
Improper use may result in such hazards as damage to the product or
malfunctions that may lead to serious accidents. Local regulations
may restrict the use of this product to below the conditions quoted.
Use hoisting equipment for heavy objects (weighing
approximately 20 kg (44 lb) or more).
Failure to do so may result in back strain or other injury if the object
should fall.
Take measures to prevent people from coming into direct contact
with product outlets.
Failure to do so may result in burns or other injury from the discharge
of fluids.
When disassembling or removing the product, wait until the
internal pressure equals atmospheric pressure and the surface of
the product has cooled to room temperature.
Disassembling or removing the product when it is hot or under
pressure may lead to discharge of fluids, causing burns, other injuries
or damage.
Continued on the next page
DANGER
WARNING
CAUTION
CAUTION

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Be sure to use only the recommended components when
repairing the product, and NEVER attempt to modify the product
in any way.
Failure to observe these precautions may result in damage to the
product and burns or other injury due to malfunction or the discharge
of fluids.
Do not use excessive force when connecting threaded pipes to
the product.
Over-tightening may cause breakage leading to fluid discharge, which
may cause burns or other injury.
Use only under conditions in which no freeze-up will occur.
Freezing may damage the product, leading to fluid discharge, which
may cause burns or other injury.
Use only under conditions in which no water hammer will occur.
The impact of water hammer may damage the product, leading to
fluid discharge, which may cause burns or other injury.
CAUTION

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Specifications
Install properly and DO NOT use this product outside the recommended
operating pressure, temperature and other specification ranges.
Improper use may result in such hazards as damage to the product or
malfunctions which may lead to serious accidents. Local regulations
may restrict the use of this product to below the conditions quoted.
CAUTION
DO NOT use the trap in excess of the maximum operating pressure
differential; such use could make discharge impossible (blocked).
CAUTION
Use only under conditions in which no freeze-up will occur. Freezing
may damage the product, leading to fluid discharge, which may cause
burns or other injury.
CAUTION
Refer to the product nameplate for detailed specifications.
* Valve No. is displayed for products with options. This item is omitted from the nameplate when
there are no options.
Acceptable Operating Range
Model
COSR-3
COSR-16
COSR-21
Primary Pressure Range
0.1 to 0.3 MPaG
(15 to 45 psig)
0.2 to 1.6 MPaG
(30 to 250 psig)
1.35 to 2.1 MPaG
(190 to 300 psig)
Adjustable Pressure
Range
(All conditions must be
met)
0.01 –0.05 MPaG
(1.5 to 7 psig)
Within 10 to 84% of the primary pressure
Minimum adjustable
pressure of 0.03 MPaG
(5 psig)
Minimum adjustable
pressure of 0.55 MPaG
(80 psig)
Pressure differential
between
0.07 –0.85 MPa
(10 120 psi)
Maximum pressure
differential of 0.85
MPa (120 psi)
Maximum Operating
Temperature
220 °C (428 °F)
Minimum Adjustable
Flow Rate
5% of rated flow
rate
5% of rated flow rate; 10% of rated flow rate for
sizes 65 mm (21/2in) and larger
(1MPa = 10.197kg/cm2)
Model
Nominal Diameter
Maximum Operating
Temperature
Valve No.*
Secondary Pressure
Adjustable Range
Primary Pressure
Range
Production Lot No.

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Correct Usage of the COSR Pressure Reducing Valve
Install properly and DO NOT use this product outside the recommended
operating pressure, temperature and other specification ranges.
Improper use may result in such hazards as damage to the product or
malfunctions which may lead to serious accidents. Local regulations
may restrict the use of this product to below the conditions quoted.
CAUTION
1. The COSR should be operated only within its specifications.
2. Installing an ON/OFF Valve (Solenoid Valve or Motorized Valve)
If an on-off valve, such as a motorized valve, is required to stop supply of steam to
the steam-using equipment, install it at the inlet side of the COSR. If a solenoid
valve is installed at the outlet of the COSR, its opening and closing will cause
heavy chattering and may lead to damage of the piston and main valve. (When
the on-off valve opens, the secondary pressure of the COSR changes from zero
to the set pressure. Passing through an area of the reducing ratio of less than
10:1, where adjustment is impossible, chattering occurs momentarily. To save
energy, it is recommended to install the on-off valve as near to the boiler as
possible.
NOTE: To prevent water hammer, it is recommended that a slow-acting motorized
on-off valve be used. In particular, if a fast-acting on-off solenoid valve is
used for frequent temperature control, the potential water hammer effect
can damage the steam-using equipment and the COSR.
3. Installing a Control Valve
A control valve installed between the COSR and the steam-using equipment
(downstream of the COSR) for controling equipment temperature may raise the
pressure between the COSR and the control valve when the control valve is
closed, depending on the spatial relationship. A safety valve should be installed
downstream of the control valve.
Note: When installing a safety valve to protect the steam-using equipment, be
sure to install it on the steam-using equipment or directly before the inlet of the
steam-using equipment. If the safety valve is installed on the outlet side of the
COSR between the COSR and a control valve, an eventual pressure rise could
activate the safety valve.
Motorized Valve
COSR
Motorized Valve
COSR
Inlet Side
Solenoid Valve
COSR
Solenoid Valve
COSR Outlet Side
COSR
Safety Valve Control
Valve
Steam-using
Equipment
COSR
Safety Valve Control
Valve
Steam-using
Equipment
COSR
Control
Valve
Safety Valve
Steam-using
Equipment
COSR
Control
Valve
Safety Valve
Steam-using
Equipment

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4. Precautions for the Installation of Additional Fittings Before or After the Reducing Valve
In order to ensure stable steam flow, the piping upstream and downstream of the
COSR must be straight runs. If a COSR is installed either directly before or after
an elbow or control valve, unevenness in steam flow may result in chattering and
unstable pressure.
To ensure stable steam flow, it is recommended that the COSR be installed on
straight runs of piping, as illustrated below.
①Inlet (primary side) of the COSR NOTE: d = pipe diameter
Maintain a straight piping run of
10 d or more when a manual
valve, a strainer or an elbow, etc.
is installed.
(Example: if nominal size is 25 mm (1
in), have 250 mm (10 in) or more)
Maintain a straight piping run of
30 d or more when an automated
valve (on-off valve) is installed.
(Example: if nominal size is 25 mm (1
in), have 750 mm (30 in) or more)
②Outlet (secondary side) of the COSR
Maintain a straight piping run of
15 d or more when a manual
valve, a strainer or an elbow, etc.
is installed.
(Example: if nominal size is 25 mm (1
in), have 375 mm (15 in) or more)
Maintain a straight piping run of
30 d or more when a safety valve
is installed.
(Example: if nominal size is 25 mm (1
in), have 750 mm (30 in) or more)
Maintain a straight piping run of
30 d or more when another
COSR is installed. (Two-stage
pressure reduction)
(Example: if nominal size is 25 mm (1
in), have 750 mm (30 in) or more)
Maintain a straight piping run of
30 d or more when a control
valve or an automated valve (on-
off valve) is installed.
(Example: if nominal size is 25 mm (1
in), have 750 mm (30 in) or more)
10d or more
COSR
Valve,
Strainer,
Elbow, etc.
Less
than
10d
COSR
Valve,
Strainer,
Elbow, etc.
30d or more
Automated
Valve COSR
Less than
30d
COSR
Automated
Valve
COSR
15d or more
Valve,
Strainer,
Elbow, etc.
Less than
15d
COSR Valve,
Strainer,
Elbow, etc.
30d or more
Safety Valve
COSR
Less than
30d
Safety Valve
COSR
COSR
Pressure
Reducing
Valve
30d or more
COSR
Pressure
Reducing
Valve
Less than
30d
Control or
Automated
Valve
COSR
30d or more
COSR
Control or
Automated
Valve
Less than
30d

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Configuration
COSR-3/COSR-6 (15 to 25 mm (1/2to 1 in))

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No.
Name
A*
B*
C*
D*
E*
No.
Name
A*
B*
C*
D*
E*
1
Main Body
16
Spring Housing
2
Cover Plug**
17
Adjustment Screw
3
Main Valve Seat

18
Spanner Cap
4
Main Valve

19
Plug –Sensing Line Port
5
Main Valve Holder

20
Lower Pilot Body Gasket



6
Piston

21
Cover Plug Gasket


7
Cylinder

22
Main Valve Seat Gasket


8
Pilot Body
23
Pilot Screen Holder
Gasket


9
Pilot Valve

24
Pilot Valve Seat Gasket


10
Pilot Valve Seat

25
Upper Pilot Body Gasket


11
Diaphragm
26
Cylinder Gasket


12
Pilot Screen

27
Piston Ring


13
Pilot Screen Holder
28
Tension Ring


14
Diaphragm Support
29
Main Valve Spring

15
Coil Spring
30
Pilot Valve Spring

*Replacement parts are available only in the following kits:
A = Maintenance Kit
B = Repair Kit for Main Valve
C = Repair Kit for Piston
D = Repair Kit for Piston Rings
E = Repair Kit for Pilot Valve
**Size 15 mm for COSR-3 is not available

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COSR-3 (32 to 50 mm (11/4to 2 in)) COSR-16 (32 to 50 mm (11/4to 2 in))/
COSR-21 (15 to 50 mm (1/2to 2 in))
No.
Name
A*
B*
C*
D*
E*
No.
Name
A*
B*
C*
D*
E*
1
Main Body
16
Spring Housing
2
Cover
17
Adjustment Screw
3
Main Valve Seat

18
Spanner Cap
4
Main Valve

19
Plug –Sensing Line Port
5
Main Valve Holder

20
Lower Pilot Body Gasket



6
Piston

21
Cover Gasket


7
Cylinder

22
Main Valve Seat Gasket


8
Pilot Body
23
Pilot Screen Holder
Gasket


9
Pilot Valve

24
Pilot Valve Seat Gasket


10
Pilot Valve Seat

25
Upper Pilot Body Gasket


11
Diaphragm
26
Cylinder Gasket


12
Pilot Screen

27
Piston Ring


13
Pilot Screen Holder
28
Tension Ring


14
Diaphragm Support
29
Main Valve Spring

15
Coil Spring
30
Pilot Valve Spring

*Replacement parts are available only in the following kits:
A = Maintenance Kit
B = Repair Kit for Main Valve
C = Repair Kit for Piston
D = Repair Kit for Piston Rings
E = Repair Kit for Pilot Valve
Contact TLV for COSR-21 replacement parts.

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COSR-16/COSR-21 (65 to 150 mm (21/2to 6 in))
No.
Name
A*
B*
C*
D*
E*
No.
Name
A*
B*
C*
D*
E*
1
Main Body
18
Spanner Cap
2
Cover
19
Plug –Sensing Line Port
3
Main Valve Seat

20
Lower Pilot Body Gasket

4
Main Valve

21
Cover Gasket


5
Main Valve Holder

22
Main Valve Seat Gasket


6
Piston

23
Pilot Screen Holder
Gasket


7
Cylinder

24
Pilot Valve Seat Gasket


8
Pilot Body
25
Upper Pilot Body Gasket


9
Pilot Valve

26
Cylinder Gasket



10
Pilot Valve Seat

27
Piston Ring


11
Diaphragm
28
Tension Ring


12
Pilot Screen

29
Seal Ring

13
Pilot Screen Holder
30
Pilot Valve Cover
14
Diaphragm Support
31
Main Valve Spring

15
Coil Spring
32
Pilot Valve Spring

16
Spring Housing
33
Silencer
17
Adjustment Screw
*Replacement parts are available only in the following kits:
A = Maintenance Kit
B = Repair Kit for Main Valve
C = Repair Kit for Piston
D = Repair Kit for Piston Rings
E = Repair Kit for Pilot Valve
Contact TLV for COSR-21 replacement parts.

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Installation
Install properly and DO NOT use this product outside the recommended
operating pressure, temperature and other specification ranges.
Improper use may result in such hazards as damage to the product or
malfunctions which may lead to serious accidents. Local regulations
may restrict the use of this product to below the conditions quoted.
CAUTION
Use hoisting equipment for heavy objects (weighing approximately
20 kg (44 lb) or more). Failure to do so may result in back strain or other
injury if the object should fall.
CAUTION
Take measures to prevent people from coming into direct contact with
product outlets. Failure to do so may result in burns or other injury from
the discharge of fluids.
CAUTION
Installation, inspection, maintenance, repairs, disassembly, adjustment and valve
opening/closing should be carried out only by trained maintenance personnel.
1. Blowdown
Before installing the COSR, be sure to
blow down all piping thoroughly. If this
is not possible, perform a blowdown
using the bypass valve.
Blowdown is especially important for
newly installed piping or after the
system has been shut down for a long
period of time.
2. Removing Seal and Cap
Before installation, be sure to remove all protective seals and caps.
(Found in 2 locations, on the product inlet and outlet.)
3. Installation Angle
Install the COSR vertically, so that the arrow
mark on the body points horizontally in the
direction of steam flow.
Allowable inclination is 10 degrees in the fore-
aft direction and 15 degrees in the plane
perpendicular to the steam flow line.
Blowdown Using Bypass Valve
Open
Closed Closed
COSR

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4. Spacer Installation
If spacing adjustment is necessary
to accommodate installation, install
a spacer on the outlet flange. The
spacer should consist of a spacer,
gaskets, bolts and nuts. Fit gaskets
to both sides of the spacer between
the COSR outlet and the pipe
flange. Fasten with bolts and nuts.
Correct
spacer
location
Incorrect
spacer
location

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5. Piping Support
Install the COSR, paying attention to
avoid excessive load, bending and
vibration.
Support the inlet and outlet pipes
securely.
6. Maintenance Space
Leave sufficient space for maintenance,
inspection and repair.
(Unit: mm (in))
7. Piping Size
If it is expected that the secondary steam flow velocity will be more than 30 m/s
(100 ft/s), install a diffuser in order to keep the flow velocity below 30 m/s (100 ft/s).
If the distance between the reducing valve and the steam-using equipment is great,
a possible drop in pressure should be taken into consideration when selecting the
piping size.
In addition, when installing the strainer, the strainer screen should be either at the
3 o’clock or 9 o’clock position to prevent condensate accumulation.
Straight piping: 10 d or longer upstream,
15 d or longer downstream
(d = pipe diameter)
COSR
Diffuser
COSR
100 (4)
100
(4) 100
(4)
100 (4)
Approx.
300
(12)
400
(16) 400
(16)

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8. Two-stage Pressure Reduction
Two-stage pressure reduction should be performed whenever the pressure cannot
be reduced to the desired level with a COSR due to operating range limitations,
such as when the reduction ratio is greater than 10:1.
9. Accessories
Always install a shut-off valve, pressure gauge and bypass line at both inlet and
outlet.
Ball valves, which will not retain condensate, are recommended for inlet and outlet
shut-off valves. The bypass pipe should be at least one half of the size of the inlet
(primary side) pipe. If installing a strainer before the COSR, horizontal installation
with the basket in the same horizontal plane to the piping is recommended in order
to prevent condensate pooling.
Safety Valve
(Relief Valve)
Pressure
Gauge
Shut-off
Valve
Bypass
Valve
Inlet Outlet
Pressure
Gauge Pressure
Gauge
Pressure
Reducing
Valve
COSR
Bypass
Valve
Shut-off
Valve Shut-off Valve Shut-off
Valve
Inlet
Valve Outlet
Valve
Safety Valve
(Relief Valve)
Primary
Side
COSR
Bypass Valve
Secondary
Side
Pressure
Gauge Pressure
Gauge
Ball Valve COSR Ball Valve
Globe Valve Safety Valve
(Relief Valve)
Pressure
Gauge
Pressure
Gauge
COSR

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External SecondaryPressure Sensing Line
For proper use of COSR with the external secondary pressure sensing line, follow the
installation procedure below.
1) Loosen and remove the bolts (nuts) that attach the pilot body to the main body or
the pilot valve cover (65 to 150 mm (21/2to 6 in)) and remove the pilot body.
2) Install the provided blind pin by first removing the connecting tube from the main
body and then substituting the blind pin.
3) Re-install the pilot body and fasten the bolts (nuts) evenly.
4) Remove the plug Rc(PT) 3/8(or NPT 3/8) and connect the secondary pressure
sensing line with a slightly falling pitch.
The end of the external secondary pressure sensing line should be connected to the
place on the steam-using equipment where the pressure is to be sensed.
A shut-off valve should be installed in the external secondary pressure sensing line.
15 to 50 mm (1/2to 2 in)
65 to 150 mm (21/2to 6 in)
Piping Example:
Body
Inlet Outlet
Plug Rc(PT) 3/8
Hex Bolt (Nut)
Pilot Body
Connecting Tubes
Pilot Body
Replace the factory-installed connecting tube
(hollow tube) with the blind pin (solid plug).
Connecting Tube Blind Pin
Valve
COSR
10 mm (3/8in) Outlet
Pressure Sensing Line
(slightly falling pitch)
1m (3.3 ft) or 15d 15d or more
Steam-using Equipment
Whichever is
larger

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Adjustment
The COSR reducing valve should be properly adjusted for protection of the steam-
using equipment against water hammer.
1. It is necessary to blow down all pipe lines thoroughly. The blowdown is especially
important if the line is new or has been shut down for a long period of time.
Take particular care to ensure that matter such as condensate and dirt does not
remain inside the steam-using equipment.
(Stay clear of any pressurized blow-out from the safety valve.)
2. Make sure that the shut-off valve and the bypass valve located upstream and
downstream of the COSR are completely closed.
3. Remove the spanner cap, loosen the locknut and turn the adjustment screw
counter-clockwise to reduce tension on the coil spring.
4. Slowly, fully open the shut-off valve at the inlet of the COSR. Allow sufficient time
for condensate remaining at the inlet of the COSR to be discharged.
5. Slightly open the shut-off valve at the outlet of the COSR.
6. Turn the adjustment screw until the desired outlet pressure is obtained. Wait
several minutes.
Tighten the Adjustment Screw
Increase Pressure
Loosen the Adjustment Screw
Decrease Pressure
7. Slowly, fully open the shut-off valve at the outlet of the COSR.
8. After setup, retighten the locknut and replace the spanner cap.
9. When shutting down the system, always close the outlet shut-off valve first and
then the inlet valve.
Loosen the locknut
Loosen the adjustment screw
Counterclockwise
Clockwise
Counterclockwise

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Maintenance
Take measures to prevent people from coming into direct contact with
product outlets. Failure to do so may result in burns or other injury from
the discharge of fluids.
CAUTION
Be sure to use only the recommended components when repairing the
product, and NEVER attempt to modify the product in any way. Failure to
observe these precautions may result in damage to the product or burns
or other injury due to malfunction or the discharge of fluids.
CAUTION
Operational Check
To ensure long service life of the COSR, the following inspection and maintenance
should be performed regularly.
Part
Inspection and Maintenance Frequency
Pilot Screen
Disassemble and clean annually.
If there is substantial blockage, install a strainer
(approximately 60 mesh) ahead of the COSR.
Main Valve, Main
Valve Seat, Pilot Valve
and Pilot Valve Seat
Replace after approximately 15,000 hours.
If there is chattering or dirt, premature wear may result.
Piston Ring
Replace after approximately 8,000 hours.
If there is chattering or if scale build-up is severe,
premature wear may result.
Piston
Replace after approximately 30,000 hours.
If hunting or chattering takes place, premature wear
may result.
Diaphragm
Replace after approximately 30,000 hours.
If hunting or chattering takes place, cracks or fatigue
may develop in a short period of time.

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Disassembly
Use hoisting equipment for heavy objects (weighing approximately
20 kg or more). Failure to do so may result in back strain or other injury if
the object should fall.
CAUTION
When disassembling or removing the product, wait until the internal
pressure equals atmospheric pressure and the surface of the product
has cooled to room temperature. Disassembling or removing the
product when it is hot or under pressure may lead to discharge of fluids,
causing burns, other injuries or damage.
CAUTION
It is a recommended practice to dismantle and inspect the COSR once a year for
preventive maintenance purposes. It is especially important to perform an inspection
immediately after the initial run of a new line or before or after equipment such as a
heater is out of service for a long period of time. (Installation, inspection, maintenance,
repairs, disassembly, adjustment and valve opening/closing should be carried out only
by trained maintenance personnel.)
Remove all steam from the piping (both upstream and downstream). If the steam
supply to the system cannot be shut off, change over to bypass operation. Close shut-
off valves at the inlet and outlet of the COSRcompletely. Relieve residual steam
pressure by slightly loosening the spring housing bolt and pilot screen holder or plug
on the sensing line port. Wait for the body to cool before attempting to remove the
COSRfrom the line. Then remove inlet and outlet flange retaining bolts and nuts to
permit removal of the COSR. Secure the COSRin a vise to perform the inspection.
Disassembling the Adjustment Section
Loosen the adjustment screw completely and remove the bolts. Having removed the
spring housing, you will see the diaphragm support, coil spring and spring guide.
Check for seizure or any damaged screw threads.
15 to 150 mm (1/2to 6 in)
Spanner Cap
Nameplate
Adjustment Screw
Ball
Spring Retainer
Coil Spring
Diaphragm Support
Hex Bolt
Spring Housing
Locknut

172-65174MA-11 (COSR Pressure Reducing Valve) 16 Feb 2022
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Disassembling the Pilot Section
The diaphragm is removed by utilizing the notch in the pilot body. Loosen the pilot valve
seat with a box wrench and remove it. Lift the pilot valve spring up and out with a pair of
tweezers. Then loosen and remove the pilot screen holder to remove the pilot screen.
Check for any fault on the pilot valve seat, flaws on the gaskets and clogging of the
pilot screen. Check for deformation, corrosion or faults on the diaphragm. The
diaphragm should be convex (open downward), with the printed “UP” mark on the
top.
15 to 50 mm (1/2to 2 in)
65 –150 mm (21/2–6 in)
Diaphragm
Pilot Valve Seat
& Gasket
Pilot Valve
Pilot Valve Spring
Plug
Pilot Body
Gasket
Notch
Hex Bolt
Pilot Screen
Pilot Screen Holder
& Gasket
Diaphragm
Pilot Valve Seat
& Gasket
Pilot Valve
Pilot Valve Spring
Plug
Hex Bolt
Pilot Body
Gasket
Notch
Connecting
Tubes
Hex Bolt
Pilot Cover
Pilot Screen
Pilot Screen Holder
& Gasket