Adding Valueby
Establishing andMaintaining a
Continuous SteamTrap
Management Program
1
Value ofContinuous Steam TrapManagement Program
•Energy Savings
•Improved Productivity andProduct Quality
•Lowered Maintenance Costs
2
Energy Savings•Systems that have not beenmaintained and evaluated in 3-5 years produce 15-30% trapfailure
•Most traps fail open, whichcauses escape of live steam tothe condensate system and inmost cases to the atmosphere,resulting in significant steamloss
3
Possible Steam Loss through25% Failed Traps
@ $12 per 1000# steam
# of Traps inSystem
# of FailedTraps
Calculatedw/ 1/8”Orifice
$ LossPer Hour
Annually@ 2080 hours
100 traps 25 1895 #phrloss $22.74 $47,299
150 traps 37 2804 #phrloss $33.65 $69,992
300 traps 75 5685 #phrloss $68.22 $141,897
4
Production and ProductQuality Improvement
•What is the value ofcontrolling condensate systemsto improve productivity?
•Can we improve product qualityby managing condensate andsteam systems?
5
6
May May MayBeforeEvaluation
AfterEvaluation
7
Starting Temp = 98.6°Ending Temp = 186.5°Temp Rise = 87.9°
Minutes to Set Point = 8 minutes
Rate of rise = 10.99° per min
Starting Temp = 111.3°Ending Temp = 199.1°Temp Rise = 87.75°
Minutes to Set Point = 14 minutes
Rate of rise = 6.26° per min
Objectives of #6 (before) and #9 (after) wereto ramp to set point as quickly as possible
May MayBeforeEvaluation
AfterEvaluation
8
Starting Temp= 134.6°Ending Temp = 151.1°Temp Rise = 16.5°
Rate of rise = 2.08° per min
Starting Temp= 122.3°Ending Temp = 139.9°Temp Rise = 17.7°
Rate of rise = 1.6° per min
Objectives of #1 (before) & #4 (after) were tocontrol a ramp of 2° per minute to the set point
May MayBeforeEvaluation
AfterEvaluation
°
9
Elements ofContinuous Steam TrapManagement Program
•Knowledge of Basic SteamPrinciples
•Knowledge of the BasicSteam System Conditions
•Tracking and ReportingEvaluations
10
Elements ofContinuous Steam TrapManagement Program
•Understanding SteamPrinciples
•Understanding the SteamSystem
•Tracking and ReportingEvaluations
11
Commitment to a Continuous Education ofSteam Principles and Application of Steam
Products• Training
• Department of Energy
• www.energy.gov
• UE Systems
• http://www.uesystems.com/
• Armstrong International
• www.armstronginternational.com/armstrong-university
• Spirax Sarco
• www.spiraxsarco.com/resources/steam-engineering-tutorials.asp
• Watson McDaniel
• www.watsonmcdaniel.com
• Available literature and website sizing
12
Steam TablesThis table states the heat values and the
pressure/temperature relationships of saturatedsteam. It contains valuable information forcalculating steam and condensate loads, steamand condensate pipe sizing, and determiningflash rates in steam/condensate applications.
This table discloses thePressure/Temperature Relationships.
At a stated pressure, the related temperature is shown. Insaturated steam, pressure and temperature arecorresponding values.
Example:
From Column 1: From Column 3:100.3 psig (gauge pressure) = 338° F (related temperature)
Pressure TemperatureRelationship
Amount of BTU per #of Steam @ this
pressure
Volume of Steam@ each Pressure
13
Flash Steam
What is flash steam?When pressurized hot condensate or boilerwater is released to a lower pressure, part of itis re-evaporated, becoming what is known asflash steam.
How does it affect my trap performance?The percentage of flash that occurs is basedon the upstream pressure before the steamtrap and the downstream pressure on thedischarge side of the trap.Flash steam can cause back pressure thataffects the performance of a steam trap andcan affect how we determine the operationalstatus of a trap.
Percentage Flash SteamSteam
PressurePSIG
Flash Tank Pressure
0 2 5 10 15 20 50 75 100
5 1.7 0.9 0.0
10 2.9 2.2 1.3 0.0
15 4.0 3.2 2.4 1.1 0.0
20 4.9 4.2 3.3 2.0 1.0 0.0
30 6.5 5.8 4.9 3.7 2.6 1.6
40 7.9 7.1 6.3 5.0 4.0 3.0
50 9.0 8.3 7.4 6.2 5.1 4.2 0.0
75 11.4 10.7 9.8 8.6 7.6 6.7 2.5 0.0
100 13.3 12.6 11.8 10.6 9.6 8.7 4.6 2.1 0.0
125 14.9 14.2 13.4 12.2 11.2 10.3 6.3 3.8 1.8
150 16.3 15.6 14.8 13.7 12.7 11.8 7.8 5.4 3.3
210 19.2 18.5 17.7 16.6 15.6 14.7 10.8 8.5 6.5
335 23.7 23.0 22.3 21.2 20.2 19.4 15.6 13.3 11.5
14
Percentage Flash SteamSteam
PressurePSIG
Flash Tank Pressure
0 2 5 10 15 20 50 75 100
5 1.7 0.9 0.0
10 2.9 2.2 1.3 0.0
15 4.0 3.2 2.4 1.1 0.0
20 4.9 4.2 3.3 2.0 1.0 0.0
30 6.5 5.8 4.9 3.7 2.6 1.6
40 7.9 7.1 6.3 5.0 4.0 3.0
50 9.0 8.3 7.4 6.2 5.1 4.2 0.0
75 11.4 10.7 9.8 8.6 7.6 6.7 2.5 0.0
100 13.3 12.6 11.8 10.6 9.6 8.7 4.6 2.1 0.0
125 14.9 14.2 13.4 12.2 11.2 10.3 6.3 3.8 1.8
150 16.3 15.6 14.8 13.7 12.7 11.8 7.8 5.4 3.3
210 19.2 18.5 17.7 16.6 15.6 14.7 10.8 8.5 6.5
335 23.7 23.0 22.3 21.2 20.2 19.4 15.6 13.3 11.5
Calculating Flash Steam Rate
% Flash Steam = SH-SL x 100H
SH = Sensible heat in the condensateat the higher pressure before inletof trapSL = Sensible heat in the condensateat the lower pressure below outletof trapH = Latent heat in the steam at thelower pressure to which thecondensate is being discharged
Example:
125.3 psig upstream, dischargingto0 psig downstream condensate line
From the steam table:
324.74-180. X100= 14.9% Flash970.2
15
Elements ofContinuous Steam TrapManagement Program
•Understanding SteamPrinciples
•Understanding the SteamSystem
•Tracking and ReportingEvaluations
16
Things are not always asthey appear!
17
How much steam pressuredo you have?
Things are not always asthey appear!
18
This plant stated thatthey had 90 to 100 psig
steam pressure atall times.
Looks likemin pressure
approx. 64.5 psig
Steam PressureSupply Line
May 12th
Looks likemax pressure
approx. 87 psig
BeforeEvaluation
19
PRESSURE
Things are not always asthey appear!
Stall in a heat exchanger,causing trap to appear
failed closed
Does it affectproductivity and quality?
20
T2
T1
Liquid IN
Liquid OUT
Steam In
Steam Trap
Recirculatingwater through
the heatexchanger
Controlvalve
responding tohigh set point
Condensatereturn lifting
about 15’
21
Unstableheat transfer
acrossheat exchanger
TEMPERATURE
BeforeEvaluation
22
Unstableheat transfer
acrossheat exchanger
May 12thRATE OF RISEBefore
Evaluation
23
TEMPERATURE
May 18thMEDIA TEMPERATURES
AfterEvaluation
24
TEMPERATURE
May 18thMEDIA TEMPERATURES After
Evaluation
25
TEMPERATURE
P3P2CVP4
PRESSURE
May 12thMay 12th
BeforeEvaluation
26
T2
T1
Liquid IN
Liquid OUT
Steam In
Steam Trap
Recirculatingwater through
the heatexchanger
Controlvalve
responding tohigh set point
Condensatereturn lifting
about 15’
27
May 18thCONDITION INHEAT EXCHANGER
AfterEvaluation
28
PRESSURE
May 18thMEDIA TEMPERATURES
AfterEvaluation
29
TEMPERATURE
ControlValve
100% Open
Back pressurein excess of 25 psig
30
Preheat Coil Trap-control valve 100% open
-high load
Trap discharge lineinto condensatecollection line
263° F approximately22.55 psig back pressure inreturn line downstream of
steam trap
31
Steam TablesThis table states the heat values and the
pressure/temperature relationships of saturatedsteam. It contains valuable information forcalculating steam and condensate loads, steamand condensate pipe sizing, and determiningflash rates in steam/condensate applications.
This table discloses thePressure/Temperature Relationships.
At a stated pressure, the related temperature is shown. Insaturated steam, pressure and temperature are correspondingvalues.
Example:
From Column 3: From Column 1:263° F (related temperature) = 22.55 psig (gauge pressure)
Back Pressure in return condensate line
32
260° F approximately20.72 psig pressure in
the steam trap
Inside of Trap
Preheat Coil Trap-control valve 100% open
-high load
33
Trap Inlet233° F approximately
7.27 psig pressure at inletto the steam trap
Preheat Coil Trap-control valve 100% open
-high load
34
Trap Outlet
260° F approximately20.72 psig back pressure
discharge outlet of thesteam trap
22.55 psig back pressure in return line20.72 psig pressure at discharge of trap20.72 psig pressure inside of trap
7.27 psig at inlet of trap
Trap cannot operate properly because of system conditions!
Preheat Coil Trap-control valve 100% open
-high load
35
36
Steam Table
Example:
15.3 inches of Vacuum = 180° F (relatedtemperature)
This table discloses thePressure/Temperature Relationships
Here in Inches of Vacuum
Heating airtemperatures to 180°F
Things are not always as they appear!
37
Heating Airwith Steam
Incoming AirTemperature = 95.3°
F
38
Heating Airwith Steam
Discharge AirTemperature =
147°F
39
Heating Airwith Steam
Steam pressurebefore control
valve
Approximately 65psig
40
Heating Airwith Steam
Steam Pressureafter
Control Valve
Approximately 40psig
With a 25 psig dropacross this valve, youwould be discharging
approximately2500 #phr of steam
41
Steam Trap
From the steam tables217 deg f =
Approximately 1.5 psiBack Pressure
Heating Airwith Steam
Condensate LinePressure after
Steam Trap
Approximately 1.5psig
With a 1.5 pressuredifferential across this
trap,you would bedischarging
approximately 2500 #phrof condensate
42
Inlet piping tosteam trap
From the steam tables206°F =
Approximately -1.6 psigor 3.0 inches Hg
Heating Airwith Steam
Condensate LinePressure Before
Steam Trap
Approximately 3.0inches Hg or
Vacuum
This means that theheat exchanger on the
steam side is in avacuum, trying todischarge into a
condensate line that is1.5 psig back
pressure.
43
HotWater
HotWater
Heating Airwith Steam
(actually hot water)
258°F = 19.55 psig183°F = Hot Water176°F = Hot Water
44
AfterSteam Trap
BeforeSteam Trap
Heating Airwith Steam
Condensate LinePressure Before
Steam Trap
Approximately 1.5psig
Was the trap blowing orwas it constantly
discharging condensateas it should?
45
Elements ofContinuous Steam TrapManagement Program
•Understanding SteamPrinciples•Understanding the SteamSystem•Tracking and ReportingEvaluations
46
Example ofComprehensive Report
47
This analysis reveals a reduction in failedtraps to below 10% on average, and clearlydemonstrates the importance of intermediate
evaluation to the process application.
48
Web-basedSteam TrapEvaluationDatabase
49