pc steam trap management presentation - ue · pdf filecontinuous steam trap management program...

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

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