ITT Skotch Trifecta T4600 Series Manual

Technical Manual No. IOT4600F Effective 8/31/2018
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ITT Engineered Valves, LLC
33 CENTERVILLE ROAD
LANCASTER, PA 17603-2064
TEL: [phone]
FAX: [phone]
www.engvalves.com
INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS
MODEL T4605F, T4606F & T4607F
SkotchTrifectaVALVE SYSTEM
WARNING
Valves and valve actuators supplied by ITT Engineered Valves, LLC are designed and
manufactured using good workmanship and materials, and they meet the applicable industry
standards. These valves are available with components of various materials, and they should be
used only in services recommended herein or by a company valve engineer. Misapplication of
the product may result in injuries or property damage. A selection of valve components of the
proper material and consistent with the particular performance requirement is important for
proper application.
Examples of misapplication or misuse of products include use in an application in which the
pressure/temperature is exceeded or failure to maintain the equipment as recommended and use
of products to handle caustic and/or hazardous substances when not designed for that purpose.
If valve exhibits any indication of leakage, do not operate. Isolate valve and either repair or
replace.

Technical Manual No. IOT4600F Effective 8/31/2018
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Record of Revisions
Revision Description Date
- First Issue 08/31/18

Technical Manual No. IOT4600F Effective 8/31/2018
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TABLE OF CONTENTS
SECTION PAGE
I. Description ................................................................................. 5
II. Operation ................................................................................... 6
III. Installation ................................................................................. 9
IV. Commissioning .......................................................................... 11
V. Disassembly & Maintenance Instructions ................................. 11
VI. Leak Testing .............................................................................. 19
VII. POC Switch Testing .................................................................. 20
VIII. Miscellaneous Instructions for Special Options ........................ 23
IX. Spare Parts Order Information ................................................... 24
X. Reference Information ............................................................... 24

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DRAWINGS
03-010 Valve Assembly – Model T4600F Systems
117374 Dimensions - Series T4600F Gas Burner Valve System - NEMA 4
117375 Dimensions - Series T4600F Gas Burner Valve System - NEMA 7
60-021 Electrical Schematic - Fail in Last
60-022 Electrical Schematic - Fail Closed
60-018 Wiring Diagram - AC Solenoids
60-024 Wiring Diagram - DC Solenoids
116763 Wiring Diagram - GO Prox Switches
117473 Pneumatic Schematic – Fail Closed
117474 Pneumatic Schematic - Fail in Last

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I. DESCRIPTION
The Series T4600F Trifecta Burner Valve System provides all the isolation and venting
functions necessary for automated operation of gas-fired burners in utility and industrial
power plants. These include double block of the main gas line and venting the chamber
between blocks to atmosphere. Hence, the term "Double Block and Vent" or “Double
Block and Bleed”. The vents are sized in accordance with Industrial Risk Insurers (IRI)
and National Fire Protection Association (NFPA) recommendations. To satisfy code
requirements, Proof of Closure (POC) switches utilizing valve seal overtravel are
supplied as standard to prove the valve is closed. Optional switch to monitor valve open
position can offer added feedback for plant DCS systems.
The Model T4605F valve system, which is the Fail-in-Last Position model, utilizes a dual
coil momentary contact pilot solenoid valve for pneumatic operation and requires
compressed air and electric power to open and close. The system fails in last position on
loss of air or electric power. It will not hold this position indefinitely if air is lost.
Model T4605F valve systems can never be Factory Mutual (FM) approved due to the
mode of failure.
The Model T4606F and T4607F valve systems, which are the Fail Closed models, utilize
a solenoid operated spring return pilot solenoid for pneumatic operation and require
compressed air and electric power to open. The system closes on a loss of pneumatic or
electric power.
Model T4606F valves incorporating specific options are Factory Mutual approved for
Natural Gas Safety Shutoff Valves per FM Approval Standard Class 7400. Valves
meeting the requirements of FM are tagged as such.
Model T4607F valves are not Factory Mutual listed with valve configuration.
Outside of the solenoid valve that controls the actuator all other aspects of the valve
system are the same between the all model numbers.
A single Skotch gas valve is typically installed in place of a multiple valves arrangement.
Consult order specification for detailed specifications of equipment supplied on each
project.

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II. OPERATION
Refer to solenoid assembly nameplate or purchase order specifications to determine
appropriate line voltage and type. Operation is in accordance with referenced drawings.
Check specific order options and wiring diagrams (60-018 for AC voltage or 60-024 for
DC voltage) for electrical terminals supplied inside the junction box.
A. Open Block Valves (Close Vent)
T4605F, T4606F and T4607F valves follow similar opening protocol.
With pneumatic supply pressure regulated to a minimum of 70 psig and a
maximum of 120 psig, apply line voltage across terminal points 1 and 2 for AC
solenoids (Terminal points 18 and 19 for DC Solenoids) located in the junction
box. This energizes the pilot solenoid, allowing pneumatic pressure into the
cylinder.
As pressure is admitted to the cylinder, the outlet valve return spring is
compressed and the outlet valve plug moves out of its seat ring. Concurrently, a
cage slides down over a post until first a soft seal, then a metal back-up seal is
made, closing the vent.
Upon vent closure, the piston continues to stroke. This pushes the inlet valve plug
out of its seat ring, compressing the inlet valve return spring. Stroking stops when
the actuator piston contacts a travel stop internal to the actuator. Flow commences
only after the inlet plug clears its seat. Thus, no flow occurs until the vent is
positively closed.

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B. Close Block Valves (Open Vent)
How the valve is commanded Closed differs for the different model numbers.
For T4605F valves:
Deleting voltage from terminal 1 and 2, and applying voltage momentarily across
terminals 2 and 3 for AC Solenoids (Terminals 20 and 21 for DC solenoids)
energizes the exhaust coil and exhausts pneumatic pressure from the cylinder.
CAUTION
Note: Never energize both solenoid coils simultaneously.
Doing so, will permanently damage the coils.
For T4606F and T4607F valves:
Deleting voltage across terminals 1 and 2 for AC Solenoids (Terminals 18 and 19
for DC solenoids) de-energizes the pilot solenoid and exhausts pneumatic
pressure from the cylinder.
For all models:
Upon exhausting the cylinder, both inlet and outlet return springs move their
respective plugs toward their seat rings. First the inlet valve soft seal makes,
halting flow through the assembly, then its metal back-up. The inlet POC switch
trips after the inlet block valve soft seal starts into its seat. Next the vent cage
moves off its post, opening the vent and relieving downstream pressure. Finally,
the outlet valve soft seal, followed by its metal back-up close, completing the
cycle. Two independent blocks are formed between system inlet and outlet, with
the chamber between the block valves ported to vent. The outlet POC switch trips
after the outlet block valve soft seal starts into its seat.
C. Notes
The quick exhaust module is equipped with a built in speed control valve. It is
located directly above the cylinder exhaust port and can be adjusted with a 1/8”
hex Allen wrench. Turning the adjustment inward or clockwise slows the opening
speed. Note: The speed control function has no effect on closing speed.

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For Model T4605F valves, the solenoid pilot valve is a dual coil momentary
contact type, rated for continuous duty at the service voltage. Note: Never
energize both solenoid coils simultaneously. Doing so, will permanently
damage the coils.
For Model T4606F & T4607F valves, the solenoid pilot valve is a maintained
contact type, rated for continuous duty at the service voltage. Note that terminal
number 3 inside the junction box is not supplied as the solenoid is a single coil
spring return versus dual coil design.
Proof of Closure (POC) switches are provided for both the inlet and outlet valves
to individually monitor the status of each block valve. The outlet valve POC is
located on the top or actuator side and the inlet valve POC is located on the
bottom of the valve assembly. Logic is shown on the referenced wiring diagram.
POC switches change contact states prior to actual commencement of flow. Both
POC switches should be used to prove valve closure. It is recommended they be
monitored individually. Some valves may be equipped with an optional open limit
switch that is located on the bottom of the valve assembly and is tripped by the
inlet valve shaft. Valves with the optional open limit switch will have a total of
three (3) switches on them.
Note: Assemblies supplied with DPDT Switches provide all terminal points
noted on Wiring Diagram. Valves supplied with SPDT switches have a
reduce number of terminals. Reference drawing (60-018 - AC, 60-024 -
DC) for details.

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III. INSTALLATION
A. Unpacking
Do not remove protective plastic plugs until ready to install.
Verify no debris or foreign objects are inside the valve.
Transporting - use proper hoisting procedures to avoid damage to valve. If using a
sling, it should be placed on the body, not the actuator cylinder.
CAUTION
Note: Valve weighs over 515 lbs in base form. Use proper
lifting safety precautions for transporting the valve.
Purge the fuel gas line prior to installing the valve.
Purge all pneumatic air lines prior to connecting solenoids.
CAUTION
Note: Do not lift or pull on the electrical conduit lines Doin
g
so may cause the POC switches to come out of calibration.
Historically many problems at start-up are due to mishandling of the valve
and poor purging of the fuel lines and pneumatic control lines.
B. Valve Installation
WARNING
Prior to installation and/or start-up, piping should be
verified as being free of dirt, grit, welding slag, or other
particulate contamination. Failure to do so may result in
damage to valve internals.

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The T4600F Trifecta Valve System is typically supplied with a female NPT vent
connection and flanged end connections. (Note: Other end configurations
available upon request.) Refer to order specification or purchase order
specifications for type supplied. Valve installation should be in accordance with
standard practices for end connection provided. Flanges are raised face carbon
steel per ANSI B16.5. Threads are per ANSI B2.1. Ensure the weight of the
system is properly supported to prevent excessive stresses. Valve should not be
supported by actuator tie rods. Valve may be installed in any orientation. Ensure
flow direction is appropriate for intended installation. Valves incorporating
welded ends should follow special precaution to insure weld heat does not
damage valve seals and gaskets. Temperatures in these areas should be kept
below 200F.
CAUTION
Vent pipe size should be equivalent to the vent fitting size
supplied. Reducing vent size may result in insufficient flow
capacity. Under NO circumstance should the vent be blocked
or plugged.
C. Pneumatic/Electrical Hook Up
Utilities required for operation are electrical power and clean dry compressed air.
Wiring should be in accordance with referenced drawings and all applicable
codes. Supply air should be connected to the 1/4" NPT inlet port on the solenoid
quick exhaust module. Purge all pneumatic lines before connecting to the
solenoid assembly. The control air lines should be filtered to 40 microns
minimum. Supply air pressure should be 70 to 120 psig at all times.
WARNING
Make certain electrical supply is isolated and tagged out
before proceeding with electrical connections.
Note: Some assemblies may include an optional filter regulator that must be
mounted by the end user.

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CAUTION
Failure to maintain proper pneumatic air line pressure could
result in damage to the valve.
Use suitable thread sealing compound only. Do not use PTFE tape.
CAUTION
The exhaust side of the solenoid should not be restricted.
This will slow the closing rate of the valve. The exhaust
module is supplied with an appropriate exhausting muffler
that ensures proper closing rate. Please consult the factory
for replacement.
IV. COMMISSIONING
After installation, connections should be tested to confirm integrity. T4600F Systems are
equipped with a 1/4" NPT test port in the protruding end of the outlet/vent shaft. See
drawing 03-010. This port is directly connected to the valve's vent chamber and may be
used to confirm seal integrity on start-up and during operation.
V. DISASSEMBLY AND MAINTENANCE INSTRUCTIONS
All T4600F Systems may be completely disassembled without removal from the piping.
However, it is recommended that it be rebuilt in a shop with suitable fixturing, hoisting
equipment and tools.
NOTE: Customers that do not feel comfortable with rebuilding and testing Skotch
valves can have them rebuilt by the factory. Call the number located on the
front cover or [phone] and ask to speak to Skotch, Customer Service for
quotation and instructions.

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Item numbers refer to referenced drawing, 03-010.
WARNING
Verify the T4600F gas valve is in CLOSED position. Ensure
all manual isolation valves are closed and tagged out, all
electrical circuits are de-energized and that the pneumatic
supply and valve are isolated and depressurized before
performing any work on the valves.
IMPORTANT: Special tools are needed for disassembly and assembly. They should be
procured before work begins.
Special tools include:
ITT P/N: 49089, Spring Compressor T4600F. Uses to compress the outlet return
spring during disassembly and assembly.
ITT P/N: 49112, Tool Seat Ring Puller T4600F. Use to remove seat rings from
valve body.
A. Disassembly
WARNING
Individual valve components can be very heavy and difficult
to remove. Use proper caution.
A clean dry area should be provided for valve disassembly. Before disassembling
the valves, the location of the junction box, vent and flange subassemblies should
be marked to facilitate ease of reassembly. Commence system disassembly by
removing accessories such as switch covers, solenoids, switches and junction
boxes from mounting surfaces on the top and bottom of the valve. Uncouple the
vent connection piping.

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Continue as follows (Reference drawing 03-010):
Unscrew Hex Nuts (Item 13) from Tie Rods (Item 27) and remove Rods.
Remove Junction Box Bracket (Item 25) and slide off Actuator Top Cap (Item
24).
Remove Actuator Shaft Wiper (Item 32), Actuator Shaft Seal (Item 33), Cylinder
O-ring Seal (Item 36), Snap Ring (Item 38), Bushing (Item 39) and O-ring (Item
37) from Top Cap.
Grasp the wall and vent port of the Cylinder (Item 23), slide it over the Piston
(Item 18) and off the assembly. Remove Cylinder O-ring Seal (Item 36) from
valve body.
Use wrench to hold flats of actuator shaft on Outlet Valve Subassembly (Item 8)
and loosen top Piston Nut (Item 22). Unscrew top Piston Nut (Item 22) from
Outlet Valve Subassembly (Item 8).
Places the Spring Compressor (P/N 49089) on Piston (Item 18) and secure tie rods
to valve body. Wrench tight the tie rods, in uniform increment, to compress the
Outlet Return Spring (Item 17) and relieving the spring force on the bottom
Piston Nut (Item 22). Unscrew the bottom Piston Nut (Item 22). Do not allow the
Outlet Valve Subassembly to rotate during nut removal. Hold on flats of Actuator
Shaft to keep from turning.
CAUTION
After removing the bottom Piston Nut it is possible for the
Outlet Valve Subassembly to fall from the bottom of the
valve. Properly support the Outlet Valve until it is removed.
Slowly unscrew tie rods of the Spring Compressor (P/N 49089). Note: the two tie
rods must be removed uniformly. The spring will completely relax prior to
disengagement.
Slide Washer (Item 21) and Piston (Item 18) off the Shaft of Outlet Valve
Subassembly (Item 8).

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Discard old Piston Gasket (Item 19) and clean surfaces of sealant.
Remove Piston Seals (Item 35) and Piston Bearing Strip (Item 20).
Remove Outlet Valve Return Spring (Item 17).
Unscrew Hex Nuts (Item 13) from Flange Studs (Item 12) taking note of the
Warning below and slip Bottom Flange Subassembly (Item 10) out of Body
Subassembly (Item 2). Care should be taken to unscrew the nuts evenly around
the bolt circle, so Inlet Valve Spring (Item 9) does not bind during disassembly.
The spring will completely relax before the nuts are unscrewed.
WARNING
When removing the Hex Nuts (Item 13) from the Flange
Studs (Item 12), remove the nuts from the long end of the
exposed threads. Removing them from the short end will not
properly unload the spring.
Remove the Inlet Valve Return Spring (Item 9).
Grasp the shaft of the Inlet Valve Subassembly (Item 7) and pull it out of Inlet
Seat Ring (Item 3).
CAUTION
With the removal of Inlet Valve Subassembly, it is possible
for the Outlet Valve Subassembly to fall from its seat ring
.
The Outlet Valve Subassembly should be properly supported.
Remove Shaft Wiper (Item 32) and Shaft Seal (Item 33) from Bottom Flange
Subassembly (Item 10). Care should be used not to scratch the bearing.
Discard old Bottom Flange Gasket (Item 11).
Remove Vent Seal (Item 30) from Inlet Valve Subassembly (Item 7). There is a
small amount of retaining Loctite on the threads of vent seal retaining screw.
Discard old Wave Springs.

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Unscrew seal retainer screws and remove seal (Item 29) and retainer from Inlet
Valve Subassembly (Item 7). There are retaining Loctite on the threads of the
screws.
Remove Inlet Valve Seat Ring retaining screw (Item 6); there are retaining
Loctite on the threads of the screws. Seat Ring Puller (P/N 49112) can be uses to
extract the Inlet Seat Ring. Insert puller behind the Seat Ring (item 3) while
longer bar on lower flange of body (Item 2), turn hex nut on stud to pull the Seat
Ring (item 3) from Lower Body (Item 2).
Discard old Seat Ring Gasket (Item 5) and clean surfaces of sealant.
Remove the Outlet Valve Subassembly (Item 8) through the bottom of the valve
body.
Remove the Outlet Valve Retainer Screws from the Outlet Valve Subassembly
(Item 8), there are retaining Loctite on the threads of screws (Item 6). Lift Outlet
Seal Retainer and remove Seal (Item 31) from Outlet Valve Subassembly.
Remove Spring Bucket Subassembly (Item 14) by unscrewing Mounting Screws
(Item 16); there are retaining Loctite on the threads. Remove Spring Bucket
Gasket (Item 15) and clean the surfaces of sealant. Remove Vent Shaft Seals
(Item 34) from Spring Bucket Sub Assembly (Item 14). Caution should be taken
not to damage the bushing.
Remove the Outlet Valve Seat Retaining Screw (Item 6); there are retaining
Loctite on the threads of the screws (Item 6). Seat Ring Puller (P/N 49112) can be
uses to extract the Outlet Seat Ring. Insert puller behind the Outlet Seat Ring
(item 4) while long bar on upper flange of body (Item 1), turn hex nut on stud to
pull the Outlet Seat Ring (item 4) from Upper Body (Item 1) through the top of
the valve body.
Discard old Seat Ring Gasket (Item 5) and clean surfaces of sealant.
Discard all seals that were removed from valve.
B. Maintenance
Periodic leak testing of both block valves and verification of proper operation of
both proof of closure switches and open limit switch (when equipped) is
recommended per applicable codes. See Section VI for leak testing and Section
VII for switch setting techniques.

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Upon disassembly, all sealing and bearing surfaces, including metal back-up
seats, should be inspected for nicks or other surface finish damage. Damaged
items should be replaced. Prior to reassembly, scrape any remaining gasket
material from mating surfaces. Wire brush and clean threads of retaining Loctite.
Clean gasket surfaces with a good quality solvent.
C. Reassembly
Bottom Flange Subassembly
Lubricate Shaft Wiper (Item 32), Shaft Seals (Item 33) and sealing surfaces in
Bottom Flange Subassembly (Item 10) with a suitable lubricant, such as, Dow
Corning 55. Install Shaft Wiper (Item 32) and Shaft Seals (Item 33) in Bottom
Flange Subassembly (Item 10). Note the orientation of wiper and seal in Detail A
of drawing 03-010.
Inlet Valve Subassembly
Use Loctite® 222 and recommended primer on cap screws that hold Seal (Item
29) and retainer. Uses Inlet Seat Ring (Item 3) as guide to set Seal (Item 29) and
ensure Seal (Item 29) is concentrate on Inlet Valve Subassembly (Item 7).
Stack the three separate vent wave springs on top of one another, in a nested
fashion. Ensuring the lap joint of the wave springs is staggered. Slide the wave
springs and spring retaining over the vent post of Subassembly. Lay Vent Seal
(Item 30) and seal retainer on top of post. Uses Loctite® 242 and recommended
primer on hex head cap screw and secure Vent Seal (Item 30) in place.
Outlet Valve Subassembly
Uses Loctite® 222 and recommended primer on cap screws that hold Seal (Item
31) and retainer. Uses Outlet Seat Ring (Item 4) as guide to set Seal (Item 31) and
ensure Seal (Item 31) is concentrate on Outlet Valve Subassembly (Item 8).
Spring Bucket Subassembly
Lubricate Vent Shaft Seals (Item 34) with a suitable lubricant, such as, Dow
Corning 55. Install Vent Shaft Seals (Item 34) in Spring Bucket Subassembly.
Note the orientation of the seals in Spring Bucket Subassembly (Item 14), refer to
drawing 03-010 Detail B and C
Actuator Shaft Bushing
Lubricate O-Ring (Item 37), Shaft Wiper (Item 32) and Shaft Seal (Item 33) with
a suitable lubricant, such as, Dow Corning 55. Install O-Ring (Item 37) in
Actuator Top Cap (Item 24). Install Shaft Wiper (Item 32) and Shaft Seal (Item
33) in Bushing (Item 39). Note the orientation of wiper and seal in bushing, refer

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to Detail D on drawing 03-010. Install Bushing (Item 39) in Actuator Top Cap
(Item 24) and use Snap Ring (Item 38) to secure Bushing (Item 39) in place.
Valve Assembly
Use a suitable gasket compound on all gaskets as noted, such as, Permatex Blue
Adhesive Sealant (RTV).
Apply gasket compound to gasket side of Outlet Seat Ring (Item 4). Press the
Seat Ring Gasket (Item 5) on to the Outlet Seat Ring (Item 4). Apply gasket
compound to other side of Seat Gasket (Item 5). Fasten Outlet Seat Ring (with
Gasket) into seat ring holder in Top Body (Item 1). Use Loctite® 242 and
recommended primer on cap screws (Item 6). Place all screws in place than
tighten in criss-cross pattern.
Lubricate the sealing surface of Outlet Seat Ring (Item 4) and circumference of
Seal (Item 31). Slide in Outlet Valve Subassembly (Item 8) from bottom of valve
body (Item 2). Care not to damage Outlet Valve Subassembly (Item 8) and it
should be supported.
Apply gasket compound to the gasket side of Inlet Seat Ring (Item 3). Press on
the Seat Ring Gasket (Item 5) and apply gasket compound to other side of Seat
Gasket (item 5). Fasten Inlet Seat Ring (with Gasket) into seat ring holder in
Bottom Body (Item 2). Use Loctite® 242 and recommended primer on cap screws
(Item 6). Place all screws in place than tighten in criss-cross pattern.
Lubricate the sealing surface of Inlet Seat Ring (Item 3), circumference of Seal
(Item 29) and face of Vent Seal (Item 30). Slide in Inlet Valve Subassembly (Item
7) from bottom of valve body (Item 2). Ensuring the post of Inlet Valve (Item 7)
engaged the cage of Outlet Valve (Item 8). Engage Seal (Item 29) into Inlet Seat
Ring (Item 3). Slide Inlet Valve Return Spring (Item9) on Inlet Valve
Subassembly (Item 7). Install Bottom Flange Gasket (Item 11) on Bottom Flange
Subassembly. Lubricate lower half of shaft on Inlet Valve (Item 7). Install Bottom
Flange on shaft of Inlet Valve (Item 7). Note the orientation of Bottom Flange and
rotate it to position. Secure flange in place using Stud (Item 12) and Nut (Item
13). Care should be taken to tighten the nuts evenly around the bolt circle, so Inlet
Valve Spring (Item 9) does not bind during assembly. Verify Return Spring (Item
9) is in the recess pockets of Inlet Valve (Item 7) and Bottom Flange (Item 10).
Tighten the flange nuts in a criss-corss pattern until snug; making certain flange is
not cocked. Torque the nuts to 200 ft-lbs in criss-cross pattern and recheck.
Apply gasket compound to the gasket side of Spring Bucket Subassembly (Item
14). Press on Spring Bucket Gasket (Item 15) and apply gasket compound to
other side of gasket. Lubricate the vent shaft of Outlet Valve Subassembly. Slide

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Spring Bucket Subassembly with gasket onto the vent shaft of Outlet Valve
Subassembly (Item 8). Care not to damage the Seals in Spring Bucket
Subassembly as it slide over the threaded portion of the Outlet Valve
Subassembly. Fasten Spring Bucket Subassembly into Top Body (Item 1). Use
Loctite® 222 and recommended primer on cap screws (Item 16). Place all screws
in place than tighten in crisscross pattern. Ensure to clean excess gasket
compound that may spilled into o-ring groove of Top Valve Body (Item 1).
Lubricate Cylinder Seal (Item 36) and install Cylinder Seal (Item 36) on groove
of Top Valve Body (Item 1).
Apply gasket compound on the face of the vent shaft of Outlet Valve
Subassembly (Item 8) Press on Piston/Shaft Gasket (Item 19) and apply gasket
compound to other side of the gasket. Slide Outlet Return Spring (Item 17) over
the Outlet Valve Subassembly and on the Spring Bucket Subassembly. Slide
Piston (Item 18) over Outlet Valve Subassembly onto Outlet Return Spring (Item
17).
Place the Spring Compressor (P/N 49089) on Piston (Item 18) and secure tie rods
to valve body. Wrench tight the tie rods, in uniform increment, to compress the
Outlet Return Spring (Item 17). Install Washer (item 21) and Piston Nut (Item
22). Do not allow the outlet shaft to rotate during installation. Hold on flats of
actuator shaft to keep from turning. With Piston firmly seated on vent shaft, fasten
top piston nut and secure in place. Remove Spring Compressor.
Lubricate Piston Seals (Item 35) and Cylinder Seals (Item 36) with a suitable
lubricant. Install Piston Seals (Item 35) and Piston Bearing Strip (Item 20) on
Piston (Item 18). Note the orientation of the Piston Seals (Item 35) refer to
drawing 03-010 and there is a 0.50” to 0.75” gap between either ends of the
Bearing Strip (Item 20). Lubricate the inside of the Cylinder (Item 23). Place the
cylinder over the actuator piston. Rotate cylinder to require orientation. Lubricate
and install Cylinder Seal (Item 36) on Actuator Top Cap (Item 24). Lubricate the
actuator shaft and place Top Cap on Actuator Shaft. Rotate the Actuator Top Cap
to proper orientation. Place Junction Box Bracket on Top Cap in the correct
orientation and fasten in place with Studs (Item 27) and Nut (Item 13). Initially
tighten the flange nuts in a crisscross pattern until snug. Final torque the nuts to 200
ft-lb in a crisscross pattern and recheck.
Lubricate the solenoid mounting o-ring with a suitable o-ring lubricant and place
on the actuator top cap. Mount the solenoid with quick exhaust subassembly to
the actuator top cap using screws and lock washers.
After re-installation of junction box, pneumatic and switches, the valve and
switches should be tested per following procedures in Section VI and VII.

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VI. LEAK TESTING
It is necessary to leak test each block valve and the vent valve individually to properly
qualify the status of each seal. The valves are named in accordance to their position and
function within the valve system.
A. Inlet Valve
1. Verify the valve is in the closed position.
2. Seal the outlet of the valve.
3. Pressurize the inlet with a maximum of 50 psig clean dry air, while
monitoring the leak rate from the vent port. FM specifies a leak rate of 24
in3/hr (400 cc/hr) or less.
B. Outlet Valve
1. Verify the valve is in the closed position.
2. Seal the inlet side of the valve.
3. Pressurize the vent port with a maximum of 50 psig clean dry air, while
monitoring the leak rate from the outlet port. FM specifies a leak rate of
24 in3/hr (400 cc/hr) or less.

ITTEngineered Valves, LLC Page 20 of 24
Technical Manual No. IOT4600F Effective 8/31/2018
REV LEVEL -
C. Vent Valve
1. Verify the valve is in the full open position.
2. Seal the outlet side of the valve.
3. Pressurize the inlet with a maximum of 50 psig clean dry air, while
monitoring the leak rate from the vent port. FM specifies a leak rate of 24
in3/hr (400 cc/hr) or less.
VII. PROOF OF CLOSURE SWITCH TESTING
The intent of the Proof of Closure (POC) switch is to trip during the closure overtravel
(flow < 24 in3/hr) portion of the stroke. The switches should change contact state before
flow commences from each individual valve. The Skotch Trifecta®Gas valve consist of
two block valves with a corresponding proof of closure switch that must be tested
individually.
The POC switches should be tested after the valve has been leak tested.
A. Inlet Valve POC Switch
1. Testing
a) With the valve in the closed position, verify the normally closed
contacts are made.
b) Very slowly open the valve until the normally closed contacts are
open. At this point stop the movement of the actuator and verify
that flow has not commenced by pressurizing the inlet with a
maximum pressure of 50 psig and monitoring flow from the outlet.
The actuator can be opened slowly by regulating the air pressure to
the actuator.
c) If there is evidence of flow the inlet valve switch needs to be
adjusted.
2. Setting
a) With the valve in closed position, remove the inlet valve switch
cover.