• Steam Trapping – Latest Trends
Importance of Steam Trapping
• Trap the Live steam and Remove Condensate Efficiently.
• It’s a crucial link between the steam and Condensate Loop
• What Considerations for selection of Traps -• Mainly – Application & Sizing • Air Venting
• Condensate Removal - at varied conditions
• Performance & Reliability – perform with minimum attention
Conventional vs Latest Trends
• Application - Header Drip legs
CONVENTIONAL TRAP INSTALLATION
1000 traps =5000 valves =5000 possiblestem and body
gasket leaks
PROBLEMS WITH TRADITIONAL TRAPPING
v Length of assembly - 600mmv Weight - 13.5kgv No of connections / welds - 21v No of components - 23v Materials of construction are variable with the
chance of corrosionv Time to install - 4 hours +v Valve leakage - 5 stems to leakv Heat emission - High
HIDDEN COSTS - PIPEWORK
v Each component must be specified/selectedv Each component must be purchased and specs
confirmedv Each component must be accounted for
v Each component may have a material certificatev Pipework must be designed and drawn
v This design must be approved
HIDDEN COSTS – WELDING
v Non Destructive Examination:-– Dye penetrant– Magnetic particle– Ultrasound– Radiography
v Sites think welders’ time is freev Welding could be sub-contracted
v Hot work permit - delay
Compact Trapping Station
• Overall length reduced to 160mm
• Only 1 component to install / select
• Only 2 welds to install in line
• All stainless steel construction for long life
• Time to install - less than 45 mins
• Weight reduced to only 4 kg
• Zero valve leakage - due to piston valve technology
• Heat emission is low - less surface area
TD Traps with swivel connectionCompact Trapping Stations for Main Line Drains
TRAP BYPASS VALVE
TRAP VENT VALVE
TRAP TEST VALVE
STEAM INLET
CONDENSATE
Universal Thermodynamic Trap
( UTD3 )
Pipeline Connector (PC01N) ----having Inlet & outlet isolationpiston valve ((integratedin singlestem-piston)
COMPARISON:PC1+UTD / CONVENTIONAL
Estimated weight : 13 kg 4.0 kg
Assembly Parts & Labor5 ea. 600# rated globe or gate valv es 1 ea. Line strainer8 ea. Sch 80 nipples 16 ea 1/2’’ welds2 ealine “tee” 1 ea. Steam trap1 ea. elbow
CONVENTIONAL PC1+UTD
720mm 160 mm
245mm
Conventional vs Latest Trend
• Application – Steam Tracing
COMPARISON: COMPACT / CONVENTIONALFOR STEAM TRAP ASSEMBLY FOR LP TRACING LINE
Estimated weight : 13 kg 4.0 kg
CONVENTIONAL PC 35 +UBP21CV
720mm150 mm
Ø
200mm
Steam Condensate
Inlet
Outlet
Bypass Valve
Thermostatic Trap with un built check valve
Pipeline connector having trap upstream isolation valve
Model: PC35 with UBP21CV
Model: PC35 with UBP21CV
Glandless Piston valve for upstream isolation valve
Steam from the tracing line
Condensate from the trap Universal Balanced Pressure
Thermostatic Trap with in built check valve (UBP21CV)
Glandless Piston valve for Bypass
Pipeline connector (PC35)
Stalling Conditions on Plate Heat Exchangers and Air Heater Batteries.
• Conventional – Ball Float Steam Traps
• Latest – Automatic Pump Traps
Heat Exchanger
P2
P1
Product Temperature Input
Stall conditions
Heat Exchanger
Stall conditions
P2
P1
Product Temperature Input
Exchanger waterlogging
Exchanger waterlogging causes:
• Reduced heat output
• Control valve hunting
• Product quality problems
• Unreliable process times due to temperature fluctuations.
• Corrosion
• Waterhammer
• Distortion and damage
• Freezing and thermal stresses of plant and piping.
• Unacceptable downtimes for maintenance and repairs.
Plate heat exchanger oversizing causes stall to occur at higher load conditions
• Waterhammer
• Escaping steam
• Frequent repairs
• Costly replacement
Air handling units: maintenance problems
‘Open University’ Project Slide 21
How the APT operates (1)
Condensate enters the body through the inlet swing check valve causing the float to rise.
The float is connected to the trap mechanism via a multi-link pivot.
If the upstream system pressure Ps is sufficient to overcome the back pressure Pb, the build up of condensate will be discharged through the opening two stage trap mechanism.
In this way, the float will automatically modulate according to the rate of condensate entering the APT, controlling the rate of opening and closure of the trap.
‘Open University’ Project Slide 22
How the APT operates (2)
With some temperature controlled equipment, it is possible for the system pressure (Ps) to be lower than the back pressure at (Pb).
If this occurs a standard trap will ‘stall’, allowing the condensate to flood the equipment being drained.
‘Open University’ Project Slide 23
How the APT operates (3)
However, with the APT, the condensate simply fills the main chamber - lifting the float until the changeover linkage is engaged, opening the motive inlet and closing the exhaust valve.
‘Open University’ Project Slide 24
How the APT operates (4)
The snap action mechanism ensures a rapid change from the trapping mode to the active pumping mode.
With the motive inlet valve open, the pressure in the APT increases above the total back pressure and the condensate is forced out through the trap seat into the plant’s return system.
‘Open University’ Project Slide 25
How the APT operates (5)
As the condensate level falls within the main chamber, the float re-engages the change over linkage, causing the motive inlet to close and the exhaust valve to open.
‘Open University’ Project Slide 26
How the APT operates (6)
As the pressure inside the APT equalises with the condensate inlet pressure through the open exhaust valve, condensate re-enters via the inlet swing check valve.
At the same time the outlet ball check valve ensures no condensate can drain back into the main chamber and the trapping or pumping cycle begins again.
Spirax condensate removal solutions-Automatic Pumping Traps
Condensate removal from multi-heater applications using the Automatic Pump Traps
Condensate removal from plate heat exchangers Automatic Pump Traps Trap Monitoring
• Why do we need to monitor Steam Traps?
Performance of Traps -- FM Energy Audit Findings
Current Scenario(FM Audit Findings and Data Base)• 85000 Steam Traps in Oil & Petro Chemical Industries
– At least 30 % need attention for s team loss !
• 1,00,000 Traps in Process Industries – At least 30% need attention for steam loss !
• As a very conservative figure, even assuming 20% as faulty traps, the steam loss at 6 bar pressure wastes @ 40 kg/hr / Trap ; would be1480000 kg/hr
• If we consider plants operating at an average of 12 hrs /day, 300 days a year that would mean overall steam loss of 5328000 Tons per year
Reasons for trap failure – our findings from customer complaints logged in the system
damaged seat16% air lock
6%
wrong alignment
6%SLR more than
crack open25%
strainer choked9%
normal wear and tear
5 %
float puncture12%
wrong application
21%
Steam trap failure
All types of steam traps failures can be classified into two broad categories
• Open condition (Steam Leak)
• Closed condition (Water Log)
Steam trap failure—open conditionIn this condition the trap leaks steam
• Leaks can be detected visually for traps discharging to atmosphere.
• Difficult to differentiate the flash steam from live steam.
• Impossible to detect in traps discharging to closed circuit.
Red light
Sensorexposed
R16CAutomatic
Tr apMonito r
Failed Open -causes
• SLR unit remains more than crack open • Trap is not properly aligned that results in
leakage • Seat is damaged .
Failed Open - Repercussions
• Wasted Steam = Wasted Fuel = Wasted Money• Steam in condensate line • Pressurisation of condensate line• Excessive back pressures acting on other traps
(group trapping)• Failure to maintain constant pressure /
temperature• Reduced pressure differential across good traps• Unsightly escaping steam• Steam starvation if supply is tight.
Steam trap failure –Failed Closed
• Leaks can’t be detected visually.
• Process temp. is not attained which gives the hint of a trap failure.
• Bypass is opened resulting in steam and condensate loss (process)
• Wet steam in process.
Obstruction
Orange Light
Sensordetects
loweredtemperature
Closed failure-causes
• Choking of strainers• Mechanical failure (Float puncture in ball float
traps)• Air lock (due to absence of TV)• Stall• Higher back pressure on steam traps• Wrong sizing of steam traps
Failed closed - Repercussions
• Bypass needs to be opened which results in steam and condensate loss and we have seen it increases the fuel bill by huge amount
• Irregular Temperature Control• Product Spoilage• Decrease in Heat Output• Damage to Plant Equipment
Steam wastage through leaking steam trapsTrap size
Avg. ori fice size in steam traps (mm)
Steam loss ( kg/h)3bar g 6 bar g 8 bar g 14 bar g
DN15 3.0 8 13 20 38
DN20 5.0 24 40 58 100
DN25 7.5 55 100 130 200
DN40 10.0 98 180 220 380
DN50 12.5 155 200 370 580
Trap monitoring methods
• Visual Inspection.• Temperature checking done manually (hot or cold
condition checked)• Sight glass. It enables the maintenance personnel to
visually check the health of the traps.• Ultra sonic method. • Spirax Spiratec Wired Steam trap monitoring system
Limitations of manual checking
• These methods are based on spot checking and the trap is believed to be “OK” until checked the next time.
• Manual checking is prone to errors and dependent on experience of the personnel.
• Generally a few traps are checked and the results applied to the whole lot.
• Some methods (ultrasonic) are very tedious and tiring and need training of personnel. It is very inaccurate if done by untrained personnel.
Current Scenario – Industrial Trap Monitoring• Industry focus on Trap Monitoring currently is once a
month at the best ( Many industries do yearly!)
• Existing solution - R 2 T trap monitor, Handheld Units ( acoustic)
• Shortcomings - Local display, wiring hassle, intermittent monitoring, No centralised data base to asses overallhealth of plant steam trapping – All resulting in huge energy loss and poor process and end product quality !
• No on line data base management system to provide proper MIS to assess energy loss hence oil / monetary loss of process plants!
- The solution???
Innovative Solution by Forbes Marshall
Forbes Marshall Innovative Solution• Wireless Trap Monitoring System (WTMS)
– WTMS is a network for monitoring the health of Steam Traps at dispersed locations in a plant.
– It is a wireless network of Steam Traps which• alerts when there is Steam Leak in trap.
• Alerts when trap water logs without condensate removal.• Monitors condensate temperature online.
Features of WTMS:• First in India.• Online energy loss or savings due to Steam Trap Leak.• Wireless Trap Monitoring System enables
– Immediate action by end user.– Reduction in Steam Loss.– Reduction in product rejections and process downtime.
• Centralized web based Graphical Interface• Traps Database Management according to Area, Type, Faults, Pressure &
Temp, Sizes.• Online Data analysis gives Steam Loss, Monetary Loss – Daily, Monthly,
Yearly basis.• Trap Health Analysis.• Different Analysis Reports enables user to take decision on Plant
Maintenance.
Benefits of WTMS
• Prompts immediate action by end user.• Reduction in Steam Loss.• Reduction in product rejections and process downtime.• Wireless Network of Traps – No need of cabling to
remote trap locations• Centralized web based monitoring enables reduced
operator interference and data available on the internet any time.
• Battery operated – no need of any power source, plus long battery life – 4 to 5 years.*
• Different Analysis Reports enables user to take decision on Plant Maintenance.
• Application -• Multi Utility Reactors in Pharma Industry • Textile Dyeing Industry
• Conventional - Ball Float Traps with condensate Drained
Specific Concernsin Condensate Recovery
in Bulk Drug/API/Chemical Plants
• Single Jacket / Coiled Multi-Utility reactors• Separation of heating and cooling utilities • Fear of Contamination of condensate due
mixture of cooling utilities with it.• Boiler Pitting due to contaminated
condensate• Batch type processes – Varying loads
Spirax Solution:Condensate Recovery System
with UAM & CCDS
• UAM will separate condensate from other utilities & enable recover and reuse condensate & its heat based on Temperature.
• CCDS will separate condensate from other utilities & enable recover and reuse condensate & its heat based on Conductivity.
Utility Automation Module
Why UAM?• Certain process reactions requires both heating as well as
cooling cycle• General opinion is that , this condensate can’t be recovered• Separation possible by channeling condensate & cooling media
into different return lines• Constantly sensing the temperature and separating heating &
cooling media• Controller (R2V) will compare the set point and temperature
sensed by RTD & accordingly controls the valve and also monitors trap Failure.
• Control Valve (PAV) then channelize the heating & cooling media into different return lines
`
OPEN
The Cycle continues….
• The same cooling cycle follows and brine is let in which is between -5’C to -20’C
• The left over brine in the jacket gets mixed with the incoming steam and the condensate temperature which is below 95 ‘C is drained thru the cooling utilities PAV and the purer condensate is recovered.