1. Shaft Sealing and Water Reduction Strategies in Water & Wastewater Treatment

2. Who We Are…
A leading global manufacturer of industrial fluid sealing systems, advanced polymer composites, cleaners, lubricants, metalworking fluids and industrial specialty products
A company with a strong commitment to innovation, helping our customers with products and programs that help them operate more reliably, efficiently and economically

3. The World of Chesterton
Founded 1884
Headquartered in Woburn, Massachusetts, US
Global Manufacturing
Worldwide distribution and service centers
Revenues of $235 million
1200 people
North America
160 Sales and Service Locations
South America
42 Sales and Service Locations
Europe, Middle East & Africa
234 Sales and Service Locations
Asia Pacific
66 Sales and Service Locations

4. Mechanical Seals
The leader in split seal technology with split seal solutions from 25mm to 900mm that cover the widest range of applications, including pumps, screw feeders, boiler feed pumps and Kaplan turbines. Only split seal with NSF61-certification.
The innovator in sealing technology bringing cassette seal technology that helps lower costs of sealing for the process industries
Innovative and patented SpiralTrac® environmental control technology to increase reliability in slurry handling and contaminated process streams.

5. Mechanical Packing & Gaskets
SuperSet® pump sealing solutions using patented SpiralTrac® technology for increased reliability with minimized flushwater requirements
Valve Sealing Program that offers high performance sealing solutions for all types of valves and offers leak free service for a guaranteed period of 5 years
Chesterton is the market leader in engineered sealing solutions for critical flanges, reactor vessels and tubular heat exchangers with a multi-year low emissions guarantee

6. Focus for Today Sealing Strategies …think about the following:
Seals represent 2 – 5% in the overall acquisition cost of a pump.
70 – 80 % of unscheduled pump shutdowns are seal/packing related.
So it’s critical to understand what sealing system is needed and how you ask for it.
The art is SPECIFYING the best sealing system…without overkill!
ENHANCE operation & MAXIMIZE Value 6

8. Common Sealing Strategies
Mechanical Packing
Single Component Seals
Cartridge Seals
Split Seals
Zero Flush Sealing System

9. Common Sealing Strategies
Mechanical Packing

11. Mechanical Packing
Resilient material formed around the shaft to create a long axial seal
An adjustable gland is used to compress the packing between the stuffing box bore and the shaft
Tightening the gland reduces the clearance
As the shaft rotates, it wears additional clearance into the packing.
This necessitates further gland tightening

12. Mechanical Packing
Friction between the shaft and packing generates heat and wear leading to swift deterioration of the shaft/sleeve.
Also solids or abrasives in the pumped fluid imbed into the packing and wear at the shaft/sleeve
Flush water must be introduced via a lantern ring to lubricate the packing arrangement.
This flush must leak to the environment.

13. FLUSH
WATER
WASTEWATER

14. FLUSH
WATER
WASTEWATER

15. EXCESSIVE WEAR ON PUMP SHAFT SLEEVES

16. EXCESSIVE WEAR ON PUMP SHAFT SLEEVES

17. Packing Summary ADVANTAGES Inexpensive acquisition cost
Don’t have to dismantle the pump

18. Packing Summary DISADVANTAGES Designed to leak
Requires excessive flush water for lubrication and cooling
Shaft/sleeve damage and replacement
Requires frequent adjustment
Housekeeping costs from leakage
Leakage impact: bearing failure; corrosion
Added power consumption
(like driving your car with the brake on)

19. Packing Summary
Perceptions
Easy to install
Easy to replace packing

20. Common Sealing Strategies
Mechanical Seals

22. Mechanical Seals Consists of two extremely flat surfaces, called faces
Held together by product pressure and spring force to prevent product from escaping to the environment.
Visible leakage that comes from compression packing is usually eliminated

23. Mechanical Seals All seals have common basic elements
Primary seal (rotary and stationary faces)
Spring mechanism (single spring, multi-spring, bellows)
Secondary Seals (o-ring, bellows, v-rings)
Metal components

24. Types of Mechanical Seals
In Water and Wastewater:
Component Seals
Single Cartridge seals
Split Seals

25. Component Seals
Most of your low cost seals typically are component seals
Can vary somewhat in cost and widely in performance.
OEM’s offer cheapest seal to get them out of warranty.

26. Component Seals O Rotating face Primary seal Springs Stationary face
Secondary seal O
Consists of the four key components of a seal: Primary seal (Faces), Secondary Seal (Teflon Wedge), spring element and metal parts)
All these elements are installed at the pump manufacturer
Requires precise measurements for proper installation

27. Component Seals
Seal faces must remain clean and undamaged during handling and installation.
Incorrect installation can occur resulting in premature seal failure
The majority of seal failures for component seals come from mis-installation or mis-application. 

28. Cartridge Seals Advantages: Self contained assembly of all components
No special skills required for installation
Hydraulically balanced
Will not fret or damage shaft
A cartridge mechanical seal is a completely self-contained assembly that includes all four elements of a mechanical seal; the primary seal, secondary seals, the spring mechanism and all metal parts. The cartridge seal is fully pre-assembled on a sleeve and enclosed in a gland. The seal faces remain in contact during handling and installation limiting damage and contamination. Measurements required for installing, while significant, are relatively easy to accomplish. Cartridge seals usually require no assembly prior to installation.    There is one item that most distinguishes a cartridge seal from a component seal. It is the location of the drive mechanism (usually set screws). On most component seals, the drive mechanism is inside the stuffing box. This requires tightening before assembly of the equipment. On a cartridge seal, the drive mechanism is outside the stuffing box and seal. This allows for assembly of the equipment before tightening. If the cartridge seal is installed on a pump, the impeller can also be adjusted before the set screws are tightened.

29. Cartridge Seals Disadvantages:
A cartridge mechanical seal is a completely self-contained assembly that includes all four sections of a mechanical seal; the primary seal, secondary seals, the spring mechanism and all metal parts. The cartridge seal is fully pre-assembled on a sleeve and enclosed in a gland. The seal faces remain in contact during handling and installation limiting damage and contamination. Measurements required for installing, while significant, are relatively easy to accomplish. Cartridge seals usually require no assembly prior to installation.    There is one item that most distinguishes a cartridge seal from a component seal. It is the location of the drive mechanism (usually set screws). On most component seals, the drive mechanism is inside the stuffing box. This requires tightening before assembly of the equipment. On a cartridge seal, the drive mechanism is outside the stuffing box and seal. This allows for assembly of the equipment before tightening. If the cartridge seal is installed on a pump, the impeller can also be adjusted before the set screws are tightened.
Disadvantages:
Initial Acquisition Cost higher than Component Seal
Must disassemble pump to remove the seal

30. Cartridge Seals – Desired Features
Hydraulically Balanced
Stationary seal
Stationary face shall be spring loaded to provide self-alignment due to stuffing box misalignment
Dynamic o-ring moves towards clean surface as face wears
Spring should be Hast C and located outside of the pumped fluid

31. Split Seals
The Best of Both Worlds
Split mechanical seals

32. Split Seals No Equipment Disassembly No Coupling Re-Alignment
Multiple trades sometimes required for component or cartridge seals (electrician, pipe fitter, rigger, mechanic)
No Coupling Re-Alignment
Easiest Field Reparability

33. Split Seal Advantages
MOST PRACTICAL SEAL TO INSTALL ON LARGE SHAFT DIAMETERS (Greater than 2.5”)
(Multiple trades issue)
When it is too difficult to change the packing sleeve or non-split seal
When down-time is expensive or critical/unacceptable
Comparable in cost to cartridge seal
Spare parts kits are relatively inexpensive
No re-alignment of pumps required
Newest designs very easy to install.

34. Split Seal Features Both pressure and vacuum Capability
Secondary seal will not damage shaft or sleeve
Springs out of the process fluid
Hydraulically balanced seal
Minimal number of components
Field repairable

35. Seal Selection Criteria

36. Seal Selection Criteria
Fluid Properties
Operating Conditions
Equipment to be sealed
Seal Design Chosen
Material Compatibility / Suitability
Environmental Controls Selected

37. Seal Selection Considerations
Shaft Size < 2.50”: Cartridge Seal
Easiest seal type to install
Due to relatively small pump size, pump dismantling not overly difficult or time consuming.
Shaft Size > 2.50: Split Seal
removal required – not easy to repair on site.

38. Materials of Construction
Water with varying degrees of Solid / Abrasives:
Face materials: HARD FACES = Silicon Carbide vs. Silicon Carbide
Secondary Seals: FKM, EPR or Aflas*
Springs: Hastelloy C** or Elgiloy***
Misc. Metal Parts 316 SS
* Registered TM of Asahii Glass Co. ** Registered TM of Hayes Int’l *** Registered TM of Elgiloy Ltd. Partnership

39. Environmental Controls

40. Environmental Controls
Strategies utilized to control the temperature, pressure and the fluid inside the stuffing box.
The controls ARE the life support system for the seal

41. Environmental Controls
From a major pump manufacturer,
“SEAL ENVIRONMENT IS CRITICAL FOR EXTENDED SEAL LIFE.
The number one cause of pump downtime is failure of the shaft seal. These failures are normally the result of an unfavorable seal environment such as improper heat dissipation(cooling) and poor lubrication of the seal faces or seals operating in liquids containing solids, air or vapors.”

42. Environmental Controls
In Water & Wastewater Treatment, controlling fluid properties and removing trapped air are the most significant concerns
Preventing solids buildup, keeping abrasives from seal faces, & preventing heat generation at the seal faces

43. Environmental Controls
Most common single seal control: FLUSH
Clean, cool fluid with restrictor bushing in the stuffing box throat to create flow
Strategy:
Try to prevent solids build up in stuffing box (15 fps under bushing)
Try to keep abrasives away from faces,
Try to push air out of stuffing box and force liquid film lubrication across seal faces.
Source of Flush water:
City Water
Plant Effluent

44. API Plan 32 – Clean Flush

45. Issues with Flush Water to Seals
Capital cost of flush systems
Reliability of flush water systems
Loss of system causes seal failure
Quality of Flush????
No Worries on quality…
We use City Water
We use Plant Effluent

46. Issues with Flush Water to Seals
City Water: Typical Cost of flush: $.002/ Gal .
Pump shaft size: 2.000”
Typical Flush rate: 2 GPM per pump
$.002 x 2GPM x 60 Min x 24 Hrs. x 365 = $
FYI…NYC = $.0049/gal., ($5151) Philly = $.005/gal. ($5256)

47. Issues with Flush Water to Seals
Plant Effluent: Cost of retreating water that has been through the plant = $$$$

48. Vertical Pump (Flooding)
BACK TO SUCTION
1/8”(3.18mm) ORFICE
Abrasives
Enter seal cavity as pump is flooded.
Air
Trapped around seal face must be vented off
The fluid dynamics in the vertical position are the same as in the horizontal position.

49. Vertical Applications – API Plan 13

50. “State of the Art” Sealing
Seal Design to Minimize Life Cycle Cost
Split seals
Effective Environmental Control
Active Throat Bushings
Reduce or Eliminate Flush Water Requirement
Eliminate flush water system wherever possible
Improve Pump/Seal Reliability
Reduce Plant Operating Cost
Satisfies KISS Principle: reliance on flush water can add unnecessary complexity

51. Active Throat Bushing
Active Throat Bushing is used with Split Mechanical Seals to reduce or eliminate flush fluid required and further enhance seal reliability by driving seal cavity circulation and exchange

52. Zero / Reduced Flush Technology
442 Split Seal
Active Throat Bushing

53. 442C Split Cartridge Seal Eliminates Equipment Teardown
Specifically designed to seal stuffing box pressure AND vacuum.
Fast, economical and easy rebuild of seal in the field, increasing uptime on the pump.
Adjustable gland fits  2, 3 or 4 bolt patterns

54. SpiralTrac Bushings

56. Trapped Air in Stuffing Box

57. Air Migrates to Seal Faces

58. Air Removed by Active Throat Bushing

59. Dirty Process Fluid in Stuffing Box

60. Active Throat Bushing Extracts Solids

61. Active Throat Bushing Technology
From one municipal client…
“…active throat bushings are both an economically and environmentally responsible upgrade for your pumping applications.”

62. Summary Common sealing strategies:
Packing & Mechanical Seals:
Design features
Advantages & disadvantages
Seal Selection & Criteria in Water & Wastewater
Environmental Controls
State of the Art Sealing in Water & Wastewater
Split Seals & Active Bushing Technology

63. Parting Gift Flash Drive
Copy of the M/S 101 presentation (Shaft Sealing Strategies…)
Sample Specifications
Seal Recommendations in Wastewater by application
Product Brochures
Installation Instructions
Environmental Controls used In Water & Wastewater
Videos
Active Throat Bushing

64. 442C Split Cartridge Seal Latest innovation in split seal technology
Simple & Quick to Install
Superior sealing reliability
Simple Field Repair

65. 442C Split Cartridge Seal

66. 442C Split Single Cartridge Seal
Simple & Quick to Install
Superior sealing reliability
Simple Field Repair
Operating Conditions
Materials
Sizes
25 mm to 120 mm
Faces
CB, CR, SC*
Pressure
711 mm Hg vacuum to 31 bar g
Elastomers
FKM, EPDM, FEPM, FFKM*
Temperature
120°C
Metals
(316SS), SuperDuplex
Speed
20 m/s
Springs
Elgiloytm
* - RSC Standard, SSC Optional
* - FFKM optional

67. Competitor Analysis