1. en l ’an 2000 100 ans d ’expérience sur la vapeur
Armstrong International
100 years of experience in
Steam applications
en l ’an ans d ’expérience sur la vapeur

2. The purpose of a condensate steam trap.
To obtain a maximum efficiency and productivity from an installations, a steam trap should not only provide the separation of water and steam. A number of criteria, grouped in four categories must be satisfied.
Operation and output
Energy conservation
Maintenance and life span
Installation/investment

3. Operating criteria Instant condensate evacuation
Adapt to flow variations
Adapt to upstream pressure variations
Functioning in presence of back pressure
Venting of non-condensables on start-up
Venting of non-condensables at steam temperature
Insensitive to climatic changes
Pressure/flow operating range
Follow the saturation curve.
Check valve fonction

4. Energy conservation criteria
Tight shut off valve and seat arrangement
No leaks at body joints
Tight shut-off at closure or no delay at closure
Efficient at low flow
Possibility of trap insulation
Sub-cooling energy conservation

5. Maintenance and life span criteria
Ability to handle dirt
Resistance to wear
Internal and external corrosion resistance
Resistance to superheat
Water hammer resistance
Resistance to damage from freezing
Easy maintenance
Easy and fast trap testing diagnostic

6. Assembly and investment Criteria
Capacity / size ratio
Price
Ease of installation
Application versatility
Spare parts prices

7. Steam straps various technology
Type Method of operation Family
Mechanical Density differencial I.B.
F.&.T
Temperature Temperature differencial B.M
Capsule
Thermodynamics Speed differencial T.D
Venturi Pressure loss Orifice

8. Inverted bucket steam trap. Principal of operation (I.B.)
Inlet
sortie
Valve and seat
Lever
Inlet Tube
Bucket
entrée
Start up mode
Outlet

9. Steam +
Air
Condensate
Presence of steam = Steam trap closing

10. Condensation phase and incoming condensate

11. Steam trap opening – elimination of condensate

12. Operational Forces

13. IB Steam trap Avantages
No loss of live steam : the steam trap water seal prevent the loss of steam.
Continuous condensate discharge
Long life expectancy
Water hammer resistance
Remove air and CO2 at saturated steam temperature

14. IB Steam trap Advantages
Adapt to upstream pressure variations
Instant response to condensate load variations
Not affected by dirt because of its discharge orifice at the top of the trap and the syphon effect when the orifice is completely open
Fail open steam trap

15. Important details of conception
The mechanism is free-floating
Valve continues to seat itself deeper with
wear, preserving a tight seal.

16. IB Steam trap inconveniencies
For all the models , except the models with connector, the IB should be installed only on horizontal or vertical lines.
Some model have a tendency to pass live steam on superheated steam application, if proper piping installation is not done .

17. Operation principals of Float & Thermostatic steam trap
Thermostatic air vent
levier
Float
Water seal valve
Start up mode

18. Presence of steam - Thermostatic air vent closing

19. F & T steam trap advantages
Can vent a large quantity of non-condensables because the air vent mechanism is distinct from the steam trap condensate mechanism.
Continuous condensate discharge without retaining water upstream of the steam trap
The discharge orifice is surrounded by a water seal, preventing live steam loss.
Capable of handling large capacity of condensate

20. F & T steam trap inconveniences
Because the orifice is at the bottom of the trap and the continuous discharge principle this steam trap is sensitive to dirt.
When steam is shut off, water stays in the steam trap body becoming sensitive to frost damage.
Water hammer can damage the float by implosion and destroy the thermostatic element.
Can’t be used in superheated steam because of thermostatic element limitations.
Fail close position.

21. Operation principals of thermodynamics steam traps
Pressure chamber
Disc
Seat
Discharge
orifice

22. Condensate
Flash Steam
Steam
Inlet
Outlet
At start-up, the condensate removes the disc from the seat

23. The steam penetrates inside the steam trap
Flash Steam
Condensate
The steam penetrates inside the steam trap

24. The steam occupies the chamber capacity – Steam trap closing

25. Condensation of steam in the steam trap chamber

26. Air
The steam trap air binds in presence of non-condensable

27. This problem appears frequently at start-up.

28. Operational Forces

29. Features of a thermodynamic steam trap
Small, light weight, easy to install.
One size orifice for all pressure ranges,
Stock reduction.
Large capacity in proportion to it’s size.
It’s one mobile part make it resistant to ‘’water hammer’’.
Competitive pricing

30. Inconveniences of the thermodynamic steam trap
The disc opening cycle depends on the pressure over the disc. The climatic conditions therefore influence the operation of each cycle, by cooling the body of the trap, where a rapid condensation of the steam and a pressure drop occur over the disc.
Operation cycle, fast at low loads, cause a premature wear and tear.
The operation cycle speeds up when seat wear appears, this accelerates the wearing process and reduces the service life of the steam trap.

31. Inconveniences of the thermodynamic steam trap
Does not close if back pressure reaches 50 % of upstream pressure.
A steam trap leak could drive other steam traps that are connected to the same line system to leak.
Does not close if a pressure drops under 5 psi.
The requirements specified for the surface conditions, makes it very sensitive to dirt.
No instant reaction to condensate loads variations. Retains the condensate between cycles.

32. 2 main reasons why the TD steam trap wear and tear rapidly
Snap closure of the disc
against the seat at each cycle.
High velocity outlet = premature
erosion of disc and lost, of seat
tightness.

33. Operation principals of thermostatic bellow steam strap
Alcohol
Valve
Seat

34. Operation principal of thermostatic bellow steam strap
Condensate
cooling
Steam

35. Operation principal of thermostatic wafer steam trap
Distilled water
+ alcohol
Diaphragm

36. Wafer steam trap opening curve
Saturation curve
Steam
Close Steam trap
temperatue
Delta T
Open Steam trap
Water
Pressure (psig)

37. Operational Forces

38. Advantages of Wafer Steam trap and Bellow Steam strap
In general sizes are small and light
Reduces the amount of flash steam
Allows sensible heat recuperation
Will adapt to pressure and discharge variations
At start-up, it will remove the non-condensables

39. Inconveniences of bellow steam trap
Sensitive to dirt
Upstream condensate retention (sub cooling) causes a reduction in Ph which develops corrosion and premature wear
Sensitive to water hammer
Not adapted for superheated steam
Can fail close

40. Bimetallic Steam Trap Adjusting screw Bimetallic strips Valve stem
Inverted valve

41. Air at Start-Up

42. Condensate
at start-up

43. Condensate
Flash Steam
Steam

44. Steam +
air

45. Operational Forces

46. Opening curve of a Bimetallic Steam Trap
Saturated curved
steam
temperature
Delta T
Close steam trap
water
Open steam trap
pressure

47. Bimetallic Steam Trap Advantages
Ability to handle start-up air loads
Recuperation of sensible heat
Reduces the amount of flash steam
Resistance to water hammer

48. Bimetallic Steam Trap inconveniences
Sensitive to dirt
Sensitive to back pressure
Sensible to upstream pressure variation
Improper continuous air venting
Not adapted for process applications
Valid capacity curves for a given temperature

49. Selection methodology for condensate steam trap
Steam Main Boiler Header Unit Heather Exchanger Tracing Drum dryer
Q=L.M.Cs.t Q=V..Cs.t Q=<1 kg/h.m
r.temps r
Q= Cap. Boiler Q=V..Cs.t Q=L.Ø..35 kg/h.m² 0, r
Qx1, QX QX QX Aucun Q x3 à QX QX3
Application
Calculation of flow in kg/h
Safety margin