Steam Systems Basics, Challenges and Troubleshooting

1. Steam Systems
Basics, Challenges and
Troubleshooting
John Cilyo
Senior Account Executive
Spirax Sarco Inc.
For
Steve Jalowiec, PE, CHFM

2. Steam Systems & Chaos
Theory
In mathematics, chaos theory describes the
behavior of certain dynamic systems – that is, systems
whose states evolve with time – that may exhibit
dynamics that are highly sensitive to initial conditions
(popularly referred to as the butterfly effect). As a result
of this sensitivity, which manifests itself as an
exponential growth of perturbations in the initial
conditions, the behavior of chaotic systems appears to
be random. This happens even though these systems
are deterministic, meaning that their future dynamics are
fully defined by their initial conditions with no random
elements involved. This behavior is known as
deterministic chaos, or simply chaos .

3. Steam Systems & the 2 nd Law
Second Law of Thermodynamics
• The entropy of an isolated system not in equilibrium will
tend to increase over time , approaching a maximum value at
equilibrium.
• In a simple manner, the second law states "energy systems have a
tendency to increase their entropy rather than decrease it." This can
also be stated as "heat can spontaneously flow from a highertemperature region to a lower-temperature region, but not the other
way around." (Heat can flow from cold to hot, but not spontaneously
—- for example, when a refrigerator expends electrical power.)
• A way of thinking about the second law for non-scientists
is to consider entropy as a measure of disorder . So, for
example, a broken cup has less order (more entropy) than an intact
one, and it is more difficult to repair a broken cup (reducing its
entropy) than to break an intact one (increasing its entropy).
Likewise, solid crystals, the most organized form of matter, have
very low entropy values; and gases, which are very disorganized,
have high entropy values.

4. Basic Steam System

5. Another view of a Steam System
Loads
Radiators, Sterilizers
Heat Exchangers, etc
Steam
Header
Steam
Traps
BOILER
Condensate
Return
Piping
(Treated)
Make up water
Deaerator
Condensate
Return Tank

6. Steam System Basics
• Boiler Design
• Water Tube, smaller steam space, need to be run closer to
•
•
design pressure
• Fire Tube, large steam chest, can be run a lower than design
pressure.
Definitions
• "Carryover" means that you have a problem with the TDS (total
dissolved solids). You need to properly define the PPM values
needed. Fire tube boilers have a normal TDS of 3000 ppm, while
water tube designs need 2000 ppm. Everyone uses the 3000
ppm value regardless of boiler type and that is their first mistake.
• "Priming" is a mechanical condition caused by too great of a
takeoff velocity (50 to 100fpm).This is corrected mechanically.
Testing
• With the boiler running, take a condensate sample from a drip pocket on
the main header. If you see a high TDS value (say 2000 PPM), you
have a carryover issue. If your value is 5 ppm or is immeasurable, you
have priming. Remember, steam has no TDS!

7. Steam systems have many end uses in
hospitals; radiators, heat exchangers,
humidification but probably none as critical
as Steam Sterilizers

8. Your Objectives
(Challenges)
• Deliver good quality steam to heating,
humidification and process equipment.
• Operate the system safely.
• Get maximum efficiency from heating
equipment - energy $$$
• Maintain the system at a reasonable cost.

9. Steam Has Another Objective In
Mind!
(Challenges)
• Condenses anywhere and everywhere it
can.
• Happily fills the system with air, in the
worst possible locations.
• Carries entrained water, gases, chemicals
and dirt into every nook and cranny.
• Will slow down and stop flowing as soon
as differential pressure is lost.

10. Your Mission Is To Stay Ahead of
Potential Problems
(Challenges)
•
•
•
•
•
•
•
Test/maintain steam traps routinely.
Clean strainers!
Clean and maintain regulators/control valves
Routine maintenance of condensate pumps.
Keep an ear open for excess pipe-line waterhammer & correct the root-cause.
Watch for repeat instances of valve wire-draw &
correct root-cause (wet steam, valve sizing)
Recognize that water hammer in heat
exchangers and heating coils is correctable.

11. Challenges
No problem – right?
All it takes is money and manpower!
Anyone here have enough of both?
But there is help:
• Boiler Water Treatment Company
• Steam Specialty Companies
• Steam Consultants
• Some of these can help for free, some will
cost.

12. Steam System Challenges
• Remember Steam Systems are dynamic systems
• Never Steady State
• Loads coming on and off
•
•
•
•
Sterilizers
Heating coils
Steam Absorption Chillers
Manual Building Heat (Old fashion radiators)
• System Sizing
• Sized for steady state or instantaneous loads (sterilizers)

13. Steam System Troubleshooting
Myths
• My boilers never carry over, prime, etc.
• The water level is always steady in the gauge
glass.
• I don’t need trap maintenance, failed traps will
become apparent on their own. (The water
hammer will tell me about a bad trap.)
• Boiler water treatment is a scam.
• Boiler blow-down wastes energy and water.

14. Steam System Troubleshooting
Steam System Chemistry
• Feed Water Quality
• Softener
• Deaerator
– Dissolved O2 and non-condensable gases
• Chemical Treatment
• Totaled Dissolved Solids (TDS)
• Blow down
• Continuous Surface
• Bottom Blow Down

15. Typical Steam System Chemistry
(May vary with chemical supplier and boiler manufacturer)
Test
pH
Sulfite % So2
(Higher in lay-up)
Typical
Limits
Low/Hi
Softener
Feedwater Boiler Condensate
Return
See chart
> 8.5
30/60
XX
Alkalinity P
200/400
Alkalinity M
Deaerator
8.3 – 9.4
XX
XX
250/500
Silica
Monitor
trends
< 150 mg/L
XX
XX
Conductivity
3000/3500
XX
XX
Calcium
< 0.3/FW
XX
Iron
Copper
Primary
Treatment Chem.
Dissolved O2
XX
XX
XX
< 0.1/FW
XX
XX
< 0.05/FW
XX
XX
Per
mfg
7 ppb
XX
XX

16. Typical Boiler Water Treatment Test Report
(partial)
Status
Polytreat
Sulfite
Alkalinity
Silica
TL-200
as SO3
P
M
Conductivity
Calcium
Iron
Copper
pH
Boiler 2
Lead
18.5
110
370
510
-
77.6
2886(N)
-
Boiler 3
Open
-
-
-
-
-
-
-
-
6.0
129
0.17
8.60
45
0.05
0.03
0.03
MR1 cond.
-
-
-
-
-
Kitchen Dish.
-
-
-
-
-
-
Softener 2
Pwr. Plnt. cond.
condensate
Sub base. large
Feedwater
Recommended
Low/
High
Limits
3.6
__10__
20
_30_
60
8.35
_200
_
400
_250
_
500
2.2
72
0.26
0.10
0.03
_8.0_
8.5
Record
__3000__
3500
_< .3_
FW
_< .1_
FW
_< .05_
FW
Courtesy of Barclay Water Management, Inc.

17. Steam System Troubleshooting
• Water Level Control
• Sight glass levels are not reliable
• Variable feed versus on/off
• Steam Flow Metering & Data
• Data is invaluable for system troubleshooting
“
You cannot manage what you
cannot measure”
Lord Kelvin

18. Why is proper condensate drainage
important?

19. Water hammer!
Result of a drip trap being removed, that was
draining a 100 psig line, before a valve

20. Steam System Troubleshooting
• Steam Traps
• Properly located
• Drip Legs properly sized
• Trap Selection and sizing
• Steam Trap Testing &

21. Steam System Troubleshooting
•
•
•
•
•
•
•
•
Steam Traps
Main Header Main header drip legs are full size
Other drip legs are properly sized
Drips located 300’ or less and any change of
elevation
Drip stations located ahead of automatic valves
Steam traps are properly sized
Steam traps are working and maintained
Missing insulation
• heat goes to cold
•
another consequence of the 2nd law thermodynamics!

23. Ineffective vs Proper Drain Points
Steam Flow
Condensate
Correct


Cross Section
Full
Diameter
Pocket
Steam Trap Set
Incorrect
Steam Flow
Cross Section
Steam Trap Set

24. Steam System
Troubleshooting
Steam Trap Testing
•
•
•
•
Visual *
Temperature **
Ultrasonic ***
Continuous monitoring systems ****
• conductivity

25. Steam System Troubleshooting
• Belts & suspenders
• Steam separators & filters
Dry Steam
Wet Steam
Condensate Outlet

26. Steam Conditioning
Dry Steam saves energy
Example: Process requires 4,645,000 Btu’s / hr
Available: 30 psig steam @ 274oF
@ 100% Dry (saturated) steam supplies 929 Btu / lb.
∴ process requires 5,000 lb/hr.
@ 90% Dryness Fraction, steam supplies 836 Btu/lb.
∴ process now requires 5556 lb /hr. A 11% Increase
@ 80% Dryness Fraction, steam supplies 743 Btu/lb
∴ process now requires 6251 lb /hr. A 25% increase

27. Steam System
Troubleshooting
• Condensate equipment operating properly
• Pumps
• Flash tanks
• Loads
• Varying loads
• Instantaneous loads - Sterilizers

28. Steam System Troubleshooting
Now what do I do
If you suddenly have problems
• What has changed?
• Go back to basics
• Start at the boiler plant and work your way out into
•
the system
Left Hand Analysis

29. Courtesy of Walt Graham Thermo Diagnostics, Co, LLC

30. Now what do I do
•
•
•
•
•
Steam Trap Repairs
Steam Trap Survey & Assessment
Steam Trap Maintenance Program
Boiler Water Treatment Modification
Steam Conditioning Equipment
• Separators
• Filters
• Repair damaged insulation
• Steam Metering (for troubleshooting)

31. Thank you!
• Questions or Comments
• Special Thanks to
– John Cilyo, Spirax Sarco
– William Wethey, Barclay Water Management
• Contact Information
–
–
–
–
Steve Jalowiec, PE, CHFM
Waterbury Hospital, 64 Robbins Street, Waterbury CT
Work 203-573-7197
Cell 203-228-3480