Forbes Marshall FMTD60-O Manual

Forbes Marshall Thermodynamic Trap
FMTD60-O
Installation and Maintenance Manual
Energy Conservation | Environment | Process Efficiency www.forbesmarshall.com

1. Preface .................................................................................1
2. Important Safety Notes ........................................................1
3. Brief Product Information ......................................................3
4. Product Working Principle ....................................................5
5. Installation Guidelines ..........................................................6
6. Start-up and Commissioning ................................................7
7. Maintenance Guidelines ......................................................8
8. Troubleshooting .................................................................10
9. Available Spares ................................................................12
10. Warranty Period .................................................................12
Table of Contents
PLEASE NOTE - Throughout this manual this cautionary symbol is used to
describe a potential damage or injury that might occur if the safety
considerations are overlooked. This symbol denotes CAUTION, WARNING or
DANGER.
Forbes Marshall Thermodynamic Trap

1
Preface:1.
This manual is intended for anyone using, commissioning, servicing, or disposing the below
mentioned products safely and efficiently.
Forbes Marshall Thermodynamic Trap [FMTD60-O] Size: DN 15 (½”).
PLEASE NOTE:
Throughout this manual the following cautionary symbol is used to describe a potential damage
or injury that might occur if the safety considerations are overlooked.
2. Important Safety Notes:
Read this section carefully before installing/operating/maintaining the product. The
precautions listed in this manual are provided for personnel and equipment safety.
Furthermore, Forbes Marshall accepts no responsibility for accidents or damage
occurring as a result of failure to observe these precautions. Note that the product is
designed to perform for non-contaminated fluids only. A contamination in the form of
chemical, foreign particle etc. can lead to problem with product performance and life
of the product.
If these products in compliance with the operating instructions are, properly installed,
commissioned, maintained and installed by qualified personnel (refer Section 2.7) the safety
operations of these products can be guaranteed. General instructions for proper use of tools and
safety of equipment's, pipeline and plant construction must also be complied with.
2.1 Intended use:
Check if the product is suitable for intended use/ application by referring to the installation
and maintenance instructions, name plates and technical information sheets.
i) The product is suitable for use as defined in the technical information sheet. In case the
need arises to use the product on any other fluid please contact Forbes Marshall for
assistance.
ii) Check for the suitability in conformance to the limiting conditions specified in technical
information sheet of the product.
iii) The correct installation and direction of fluid flow has to be determined.
iv) Forbes Marshall products are not intended to resist external stresses, hence necessary
precautions to be taken to minimize the same.
2.2 Accessibility and Lighting:
Safe accessibility and working conditions are to be ensured prior to working on the product.
2.3 Hazardous environment and media:
The product has to be protected from hazardous environment and check to ensure that no
hazardous liquids or gases pass through the product.
FMTD60-O

2
2.4 Depressurizing of systems and normalizing of temperature:
Ensure isolation and safety venting of any pressure to the atmospheric pressure. Even if the
pressure gauge indicates zero, do not make an assumption that the system has been
depressurized. To avoid danger of burns allow temperature to normalize after isolation.
2.5 Tools and consumables:
Ensure you have appropriate tools and / or consumables available before starting the work.
Use of original Forbes Marshall replacement parts is recommended.
2.6 Protective clothing:
Consider for the requirement of any protective clothing for you/ or others in the vicinity for
protection against hazards of temperature (high or low), chemicals, radiation, dangers to
eyes and face, noise and falling objects.
2.7 Permits to work:
All work to be carried out under supervision of a competent person. Training should be
imparted to operating personnel on correct usage of product as per Installation and
Maintenance instruction. “Permit to work” to be complied with (wherever applicable), in
case of absence of this system a responsible person should have complete information and
knowledge on what work is going on and where required, arrange to have an assistant with
his primary goal and responsibility being safety. “Warning Notices” should be posted
wherever necessary.
2.8 Handling:
There is a risk of injury if heavy products are handled manually. Analyze the risk and use
appropriate handling method by taking into consideration the task, individual, the working
environment and the load.
2.9 Freezing:
Provision should be made to protect systems which are not self-draining, against frost
damage (in environment where they may be exposed to temperatures below freezing point)
to be made.
2.10 Product Disposal:
It is necessary to dispose this product only in accordance with local regulations at the
authorized, qualified collecting point specified for equipment’s and its parts—Please refer
the part details mentioned in the material table of this manual.
Please follow all waste disposal guidelines (Management & Handling) as published by local
governing authorities in India & abroad
2.11 Returning products:
Customers and Stockist are reminded that, when returning products to Forbes Marshall they
must provide information on any hazards and the precautions to be taken due to
contamination residues or mechanical damage which may present a health, safety or
environmental risk.
This information must be provided in writing including Health and Safety data sheets
relating to any substances identified as hazardous or potentially hazardous.
Forbes Marshall Thermodynamic Trap

3
3. Brief Product Information:
FMTD60-O
3.1 Description:
Forbes Marshall Thermodynamic Trap, FMTD60-O, with inbuilt strainer and full stainless
steel construction is best suited for header and mainline drains and drip legs.
3.2 Size and End Connections:
DN15 Screwed BSPT/BSP/NPT
3.3 Limiting Conditions:
PMO-Maximum operating pressure 21bar g
TMO-Maximum operating temperature 400°C
Cold hydraulic test pressure 42 bar g
Minimum pressure for satisfactory operation 0.25 bar g
PMOB-Maximum back-pressure should not exceed 80% of the inlet pressure.
3.4 Operating Range:
Figure 1: Forbes Marshall Thermodynamic Trap [FMTD60-O]
Temperature °C
Pressure bar g
Steam
saturation
curve
0510 21
0
100
200
300
400
425
2
1
5

4Forbes Marshall Thermodynamic Trap
Dimensions (approx. in mm)
Size A B C D E Weight
DN 15 33 62 40 36 45 0.5 Kg
Figure 2: Dimensional Drawing of FMTD60-O
Materials:
No Description Material Standard
1 Body St.Steel ASTM A743 Gr. Ca40
2 Cap St.Steel BS 3146 PART2 ANC2
3* Disc St.Steel ASTM A240 SS 420
4* Strainer Screen St.Steel Type 304 ASTM A24
5 Strainer Cap St.Steel BS 3146 PART2 ANC2
3.6 Capacity Chart:
0
5
10
15
20
25
0 50 100 150 200 250 300 350
Differential pressure bar g
Condensate Kg/hr
3.5 Product Dimension and Drawing:
Note: 3*and 4* shown in figure 5

5
4. Product Working Principle:
The Forbes Marshall Thermodynamic Trap works on thermodynamic principle using the dynamic
effect of flash steam as hot condensate passes through the trap.
4.1. Operation of Forbes Marshall Thermodynamic Trap : [Refer figure 3]
1. The Forbes Marshall Thermodynamic Trap operates on thermodynamic principle using
the Bernoulli theorem i.e. the total pressure energy (static and dynamic) for a moving
fluid is same at all points.
2. Condensate enters the trap through post integral strainer screen (E) in the trap. There
is an increase in dynamic pressure of the steam and hot condensate flowing under the
disc (A), as the velocity of flow increases and consequential drop in static pressure since
the total pressure must remain constant, resulting in disc (A) being drawn downward
to the concentric seat rings (C).
3. As the disc (A) is drawn downwards, flash steam passes between the edge of the disc
(A) and the inner face of the cap (D) of the trap. The flash steam occupies the space in
the top surface of the disc (A).
4. The flash steam above the disc (A) exert pressure on the larger area on the top surface
area of disc (A) overcomes the inlet pressure acting on a smaller area at the bottom of
the disc (A). The disc (A) snaps shut against the concentric body seat rings (C) and
prevents further flow.
5. This position of the disc (A) continue until the flash steam above the disc (A) starts
condensing by radiating heat from the cap (D). Post the condensation of flash steam
the pressure acting on top of disc (A) is relief and the cycle mention in points 2,3,4 and
5 is repeated.
6. The Forbes Marshall Thermodynamic Trap has an intermittent discharge pattern. The
frequency of which is determinant by the condensate load and ambinent temperature.
Figure 3 : Forbes Marshall Thermodynamic Trap
A
D
B
E
C
FMTD60-O

6
5. Installation Guidelines: [Refer figure 4]
Note:Before implementing any installations observe the 'Important Safety Notes' in
Section 2. Referring to the installation and maintenance instructions, name – plate and
technical information sheet check the product is suitable for the intended installation.
1. Check materials, pressure and temperature and their maximum values.
2. Before installation, flush the inlet drip leg to remove all dirt and oil. Ensure to remove all
protective seals from the trap.
3. The Forbes Marshall Thermodynamic Trap should be installed in a horizontal plane such that
disc movement happens only in vertically up and down directions.
4. The horizontal mainline should be provided with proper collecting pocket as provided by
equal Tee should end with a drip leg and at the end of the drip leg Forbes Marshall
Thermodynamic Trap should be fitted. Typically recommended drain pocket dimensions
relative to steam main pipe sizes are given below.
Note: Condensate should not be drained through a small pipe connection at the bottom of
mainline.
Figure 4: Recommended installation of Forbes Marshall Thermodynamic Trap on mainline
5. Isolation valves should be installed to allow for safe maintenance and trap replacement.
6. Always open isolation valve slowly until normal operation condition is achieved this will
avoid system shocks. Check for leaks and attend if any.
Note: If the trap is to discharge to atmosphere ensure it is to safe place, the discharging fluid
may be at a temperature of 100°C.
Mains
diameter-D
Pocket
diameter-d1
Pocket
depth-d2
Upto 100mm d = D
1Min d = 100mm 2
125-200mm d = 100mm
1Min d = 150mm 2
250 mm & above d > D/2
1Min d = D 2
D
d2
d1
Steam mainline
FMTD60-O
Hot condensate
to return or drain
To drain
Forbes Marshall Thermodynamic Trap

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6. Start-up and Commissioning:
6.1. Flushing of lines:
As part of pre-installation all fluid handling equipment particularly piping should be
thoroughly cleaned of scale and the internal debris which accumulates during construction.
This is accomplished by blowing or flushing with air, steam, water and other suitable
medium.
Follow these steps to carry out the flushing
1. Close the upstream trap isolation valve and open the bypass isolation valve.
2. Let the condensate drain for 10-15 minutes or until clear condensate starts coming out,
whichever is earlier.
3. Now slowly close the bypass isolation valve and open the trap isolation valve.
Note: For a detailed procedure on flushing of lines please visit Forbes Marshall website.
6.2. Commissioning:
After installation or maintenance ensure that the system is fully functioning by confirming
fluid is passing through it.
1. After flushing of lines is complete, ensure that bypass isolation valve is closed and
upstream trap isolation valve is opened.
2. Check for leaks and attend if any.
FMTD60-O

8
7. Maintenance Guidelines:
Note: Before undertaking any maintenance of the product it must be isolated from both supply
line and return line and ensure pressure is normalized to atmosphere. The product should then be
allowed to cool. When re-assembling ensure that all joint faces are clean.
7.1. Routine and preventive maintenance:
Please refer to the maintenance schedule mentioned in the table below to undertake
routine maintenance of the Forbes Marshall Thermodynamic Trap
7.2. Tool Kit:
To carry out maintenance of the Forbes Marshall Thermodynamic Trap refer the tools
mentioned in the table below.
7.3. Recommended tightening torques:
Table 1: Recommended tightening torque
No. Parameters to be checked
Frequency for checking various parameters
Immediate Daily Weekly Monthly Quarterly Half
Yearly Annually
1Test High Pressure steam traps (17.5 bar g
and above) Y
2Test Medium Pressure steam traps (3.5 bar
g to 17.5 bar g) Y
3Test Low pressure steam traps ( below 3.5
bar g) Y
4Repair / Replace steam traps - when testing
shows leaks Y
5 Clean internals / strainer of FMTD60-O Y
6 Visual Inspection for leakages Y
7 Arresting any other leaks Y
Size Component Tool used and size
DN 15 (½”)
Cap Box spanner 36 mm (A/F)
Strainer cap Box spanner 13 mm (A/F)
Foliac Graphite sealer for main bore cap and
strainer cap (Loctite 577)
Item Component Torque Range
2 Cap 180 - 200 Nm
5 Strainer Cap 170- 190 Nm
Forbes Marshall Thermodynamic Trap

9
7.4. Procedure to service trap: [Refer figure 1]
1. Unscrew the main bore cap (2) using a spanner 36 (A/F). Do not use a pipe wrench
which may cause distortion to the main bore cap (2).
2. Any minor or major damage / scratch on the seating surface of the disc (3) or body seat
(1) will cause the steam trap to pass steam. Since the disc (3) is less hardened than the
body seat (1), fine particle passing through the steam trap (along with the condensate)
could damage the disc (3). This damage will be in the form of scratches on the disc (3)
surface area. If the scratch depth is not much this can be cured by lapping the disc (3)
and the steam trap can be made functional. If the body seat (1) is slightly worn out it
can be refaced by lapping individual on a glass surface plate. The amount of material to
be removed by lapping should not exceed 0.25mm (0.010”).
Lapping Procedure:
a) Requirement: Emery paper, glass surface plate, lapping paste (Aluminum Oxide slurry)
and oil.
b) First, lap the disc on a piece of emery paper (grade 220) to eliminate scratches on the
disc and to prepare the surface for further fine lapping.
c) Apply the lapping paste and oil on to the glass surface and rotate the disc in the shape
of the numeric “8” (Eight).
d) Lapping should be done till all scratches on the disc disappear.
Note: If the scratches on the disc are not curable then the disc should be replaced.
3. When re-assembling the main bore cap (2), place the disc (3) in position with the
grooved side in contact with the body seating face (1). No gasket is required but a finer
smear of molysulf high temperature grease should be applied to the threads. The
assembly of the main bore cap (2) should be tightening to recommended torque as
mention in Table 1.
7.5. Procedure to clean/ replace the strainer screen: [Refer figure 1]
1. Unscrew the Strainer cap (5) using an Allen key (12 A/F), withdraw strainer screen (4)
and clean or if damaged replace with new one.
2. To reassemble, insert the strainer screen (4) in the strainer cap (5) and tighten the
strainer cap (5) with recommended torque as mention in Table 1.
3. No gasket is required but a finer smear of molysulf high temperature grease should be
applied to the threads.
7.6. Steamtraps testing:
Following methods can be used to determine the operating condition of a trap and
determine if its working properly:
1. Testing traps through visual inspection.
2. Testing traps using temperature gun / equipment.
3. Testing traps using sound/ultrasound.
4. Testing traps through online monitoring.
FMTD60-O

10
8. Troubleshooting:
If the expected performance is unachievable after installation of the Forbes Marshall
Thermodynamic Trap, check the following points for appropriate corrective measures.
Failure Mode Possible Cause Remedy
No Condensate
is discharged
(blocked).
Inlet drip leg or strainer screen is
clogged with rust or scale.
Flush inline drip leg and clean strainer
screen. Ifstrainer screen is rusted, replace
with new strainer screen
Differential Pressure is low.
Verify inlet and outlet pressure of the
steam trap. Minimum differential
pressure required is 0.25 bar g
Air – Binding problem. Loosen Main bore cap and tighten to
suitable torque.
Steam trap body is hot but no
condensate discharge.
To release flash steam locked (trapped)
inside the steam trap, pour water on
main bore cap of the steam trap to check
it discharge condensate.
Steam leakage.
Steam Leaking continuously.
Ensure Bypass valve is fully closed.
Check installation i.e. main bore cap to
be on top and fluid flow direction same
as arrow on the steam trap body.
Foreign material or oil film on disc
or body seat.
Clean both disc and body seat, flatness
on disc and body seating faces can be
improved by lapping individually on flat
surface or glass plate.
Note: The total amount of metal from
body seat face removed should not
exceed 0.25mm (0.01”).
Disc stuck to the main bore cap.
Give a light tap on top of the main bore
cap and check if step (inner surface of
the main bore cap) is worn out. If step is
worn out replace with new steam trap.
Back pressure exceeds allowable
value.
Outlet pressure of the steam trap should
not exceed 80% of the inlet pressure.
Forbes Marshall Thermodynamic Trap

11
Note: Never attempt to modify the product. When replacing part with new part, use the spare
parts listed in Section 9.
Failure Mode Possible Cause Remedy
Motor-boating
(chattering) of
disc.
Scratch on disc or body seat.
Check if scratch depth is less then disc
and body seating faces flatness can be
improved by lapping individually on flat
surface or glass plate. If scratch depth is
more replace with new disc. Note: The
total amount of metal from body seat
face removed should not exceed 0.25mm
(0.01”).
Disc or body seat is worn.
Replace with new disc. If body seat is
slightly worn it can be refaced by lapping
on flat surface or glass plate. If body
seat is worn more replace with new
steam trap.Note: The total amount of
metal from body seat face removed
should not exceed 0.25mm (0.01”).
FMTD60-O

12
9. Available Spares: [Refer figure 6]
The spare parts available are shown in heavy outline. Parts drawn in broken line are not supplied as
spares.
Figure 5: Parts Available as spares (Heavy outline) for FMTD60-O
10. Warranty Period:
As per ordering information and agreements in the contract.
Forbes Marshall Thermodynamic Trap
ĦĹÖŎHÓÅ SPARE TYPE SPARE CONSIST OF SPARE
SPECIFICATION SPARE CODE
A,B SCREEN AND
DISC KIT
SCREEN AND DISC
(PACK OF 5 EACH) DN15 SPARE-FMTD60O-SDKIT
DISC
SCREEN
CAP WITH
ALLEN KEY
HOLE

13
FMTD60-O

Doc# FMSS/08/16/UM-FMTD60-O/R1
Forbes Marshall Pvt Ltd
Manufacturing: B-85, Phase II Chakan Indl Area, Sawardari, Chakan
Tal. Khed, Dist, Pune 410 501. Tel: [phone]
Sales: Opp 106th Milestone, Bombay Pune Road, Kasarwadi,
Pune 411034 Tel.: [phone]
CIN No: U28996PN1985PTC037806
Doc# FMSS/0218/UM-FMTD60-O/R1
Disclaimer:
This information is strictly proprietary and legally privileged. All contents herein shall be the property of Forbes
Marshall Pvt Ltd and having protection under the intellectual property rights. No part of this information or data may
be distributed or disclosed in any form to any third party. Any dissemination, use, review, distribution, printing or
copying is strictly prohibited, if you are not the intended recipient or user of this information.
Email : [email protected] www.forbesmarshall.com
ITEM CODE NO.- 99-001-1018375