Topstock House Crewkerne

Transcription

1 PRODUCT LITERATURE

2 Based in Crewkerne, Somerset, UK and following in the tradition of Trist; Bestobell and Sterling Mechanical Seals; S M Seals specialise in the design, test, manufacture and supply of an extensive range of mechanical sealing solutions for the Power Generation Industry. Topstock House Crewkerne Design of the reversible pump turbine seal began in the late 1960 s whilst working in close co-operation with our client, this resulted in the first installation and commissioning of this type of seal at the Cruachan Pump Storage Scheme, Scotland in The development was a natural progression from many years experience, dating from 1953, in designing and supplying seals for main Cooling Water Pumps in Fossil and Nuclear fuelled power stations. Its success heralded the start of a new era for our range of Water Turbine Main Shaft Seals for the Hydropower Industry. Following on from testing and development at Cruachan, came a contract awarded for Dinorwig - the largest pump storage station in the UK. Working in partnership with their engineers and through detailed in-house tests and field trials; we have been able to advance considerably the reliability and materials of construction for our seals Our design centre uses the latest design software, which includes 3D and Finite Element Analysis (FEA) modelling. All seals are 3D modelled to ensure compatibility and FEA conducted on critical components to ensure structural integrity. Furthermore, we have an in-house Research and Development lab with which we can simulate our customers operating parameters on our unique scale model test rig, from which we gather and analyze critical data. Refinement of our seals is a continuous program and our test rig data acquisition and signal-processing equipment used in conjunction with design office software allows us to achieve our aims. Mission Statement We are committed to generating long-term commitment to our employees which aids our efforts in developing and supplying quality solutions that exceed all our customers expectations

3 TYPE HH RANGE OF SHAFT SEALS The HH Range of Seals are suitable for all types of turbines, including reversible pump turbines. If there is access for adjustment after installation then face loading can be achieved by using Springs or Weights, when no access is available then Pneumatic Cylinders can be used to load the faces. All HH Type Seals are custom designed and are fully split for ease of installation and maintenance. The main wearing face is made from a special composite material that will regenerate mutually conforming seal faces if damaged by abrasive particles. The design can be adapted to suit either horizontal or vertical shafts (weights can only be used on vertical shafts), and are capable of operating at circumferential velocities up to 30 m/sec (100 ft/sec), and pressures up to 10 bar (150 p.s.i.). With hydrostatic feed these parameters can be increased. HHSS Type Seal (fig 1): The Cone (C) is secured to the shaft, and rotates with the shaft. The composite fibre End Seal (A) is located in the Sleeve (D) and is secured in position by the Retaining Ring (B). Face loading is achieved by Springs (P) and turbine water pressure. Fig 1, As the End Seal (A) wears, the Sleeve (D) slides through the Main O-Ring (H) which is located in Top Plate (G).

4 The Wear Indicator System (J/K) can be linked mechanically to a gauge panel or electronically to a digital display unit (mechanical version shown). All metallic components can be supplied in a choice of materials to suit individual applications. Cooling water, which can be unfiltered penstock water, must be supplied to the seal under all working conditions (whenever the shaft is rotating) if hydrostatic feed is not utilised. If hydrostatic feed is incorporated into the seal, the water supply to this feed needs to be filtered to 25 microns (100 mils). HHSW Type Seal (fig 2): The HHSW seal is only used on vertical shafts as seal loading is achieved by using weights. Once the correct seal loading has been achieved there is no need for periodic adjustment until planned maintenance is required. The weight rings are supplied in different weights so that the rings can be added or subtracted until the desired seal loading has been achieved. Fig 2, HHSC Type Seal (fig 3): The HHSC seal is used only where there is no access to the seal after installation. Seal loading is achieved by using pneumatic cylinders which are controlled by a regulator on a simple control circuit. This arrangement is the most suitable for use on reversible pump turbines. Fig 3,

5 The full HH Type Seal product range includes: HHSS Straight Springs HHSW Straight Weights HHSC Straight Cylinders HHCS Cantilevered Springs HHCW Cantilevered Weights HHCS Cantilevered Cylinders FFHH Flat Face with Cylinders Benefits Positive Sealing - Hydraulically balanced faces dimensioned to suit the application to give minimum leakage. Long Life Seal life is built in and this combined with a wear indicator facilitates planned maintenance. Seal face life in excess of ten years has been achieved. Non-Clogging Smooth contours and no springs in the water prevent clogging in silty conditions. Durable Materials All wetted components are manufactured from corrosion resistant materials. Robust The composite wearing face can be dropped without damage unlike carbon. It can also withstand vibration and abrasives without permanent damage. Space Saving Custom designed seals can usually be engineered to fit into the available space allocated for the main shaft seal. Easy Maintenance Simple robust components are easier to handle and fit than multi-segment carbon glands, thereby, reducing downtime and maintenance costs. Flexible Design Can accommodate axial and radial shaft movements without special precautions.

6 TYPE WPR SHAFT SEAL The WPR Type Seal is suitable for all types of turbines, including reversible pump turbines and as face loading is remotely controlled by water pressure it is particularly suited to turbines where there is no access to the seal for adjustment after installation. All WPR Type Seals are custom designed and are fully split for ease of installation and maintenance. The main wearing face is made from a special composite material that will regenerate mutually conforming seal faces if damaged by abrasive particles. The design can be adapted to suit either horizontal or vertical shafts, and is capable of operating at circumferential velocities up to 30 m/sec (100 ft/sec), and pressures up to 10 bar (150 p.s.i.). With hydrostatic feed these parameters can be increased. Referring to the sketch: The composite fibre End Seal (A) is secured to the turbine shaft/flange/nut cover by a Retaining Ring (B), and rotates with the shaft. The Stationary Seat (Piston) (C) is loaded by water pressure in the Operating Chamber, and slides axially between the O-Rings (F & G) in the Inner (D) and Outer (E) Housings, to compensate for wear. The operating chamber is pressurised by connecting it to either a header tank, the chamber around the seals via a control device or a separate water source through a custom built control circuit through a regulator.

7 Typically the Outer Housing (E) is bolted to either a Support Housing (L) or directly on to a radial flange on the turbine head cover. The Wear Indicator Rod (J) can be linked mechanically to a gauge panel or electronically to a digital display unit (electronic version shown). All metallic components can be supplied in a choice of materials to suit individual applications. Cooling water, which can be unfiltered penstock water, must be supplied to the seal under all working conditions (whenever the shaft is rotating) if hydrostatic feed is not utilised. If hydrostatic feed is incorporated into the seal, the water supply to this feed needs to be filtered to 25 microns (100 mils). Benefits Positive Sealing - Hydraulically balanced faces dimensioned to suit the application to give minimum leakage. Long Life Seal life is built in and this combined with a wear indicator facilitates planned maintenance. Seal face life in excess of ten years has been achieved. Non-Clogging Smooth contours and no springs in the water prevent clogging in silty conditions. Durable Materials All wetted components are manufactured from corrosion resistant materials. Robust The composite wearing face can be dropped without damage unlike carbon. It can also withstand vibration and abrasives without permanent damage. Space Saving Custom designed seals can usually be engineered to fit into the available space allocated for the main shaft seal. Easy Maintenance Simple robust components are easier to handle and fit than multi-segment carbon glands, thereby, reducing downtime and maintenance costs. Flexible Design Can accommodate axial and radial shaft movements without special precautions.

8 TYPE MTSS SHAFT SEAL The MTSS Type Seal was primarily designed for the tube and S type turbines but are now largely used as an externally mounted seal, these are ideal for mini-turbines and cooling water pumps for the fossil and nuclear industries. They are particularly suited to retro-fit work. All MTSS Type Seals are custom designed and are fully split for ease of installation and maintenance. The main wearing face is made from a special composite material that will regenerate mutually conforming seal faces if damaged by abrasive particles. The design can be adapted to suit either horizontal or vertical shafts, and is capable of operating at circumferential velocities up to 10 m/sec (32 ft/sec), and pressures up to 5 bar (72 p.s.i.). With hydrostatic feed these parameters can be increased. Referring to the sketch: The Cone (C) is secured to the shaft, and rotates with the shaft. The composite fibre End Seal (A) is located in the Sleeve (D) and is secured in position by the Retaining Ring (B). The Main O-Ring (H) is located in Top Plate (G) but this can be the turbine/pump head cover. Studs (K) pass through holes in the Retaining Ring (B) and channels in Sleeve (D), and screw into the Top Plate (G). The load between the sealing faces is applied by Compression Spring (L) with Adjusting Nut (M). If installed on a turbine the water pressure will also add load.

9 As the Cone (C) wears the Sleeve (D) slides through the O-Ring (H) and the face load is maintained by the Adjusting Nut (M). All components can be supplied in a choice of materials to suit individual applications. Cooling water, which can be unfiltered penstock water, must be supplied to the seal under all working conditions (whenever the shaft is rotating) if hydrostatic feed is not utilised. If hydrostatic feed is incorporated into the seal, the water supply to this feed needs to be filtered to 25 microns (100 mils). A wear indicator can be supplied to monitor the life of the seal. This can be fitted either to the seal itself or remotely. Benefits Positive Sealing - Hydraulically balanced faces dimensioned to suit the application to give minimum leakage. Long Life Seal life is built in and this combined with a wear indicator facilitates planned maintenance. Seal face life in excess of ten years has been achieved. Non-Clogging Smooth contours and no springs in the water prevent clogging in silty conditions. Durable Materials All wetted components are manufactured from corrosion resistant materials. Robust The composite wearing face can be dropped without damage unlike carbon. It can also withstand vibration and abrasives without permanent damage. Space Saving Custom designed seals can usually be engineered to fit into the available space allocated for the main shaft seal. Easy Maintenance Simple robust components are easier to handle and fit than multi-segment carbon glands, thereby, reducing downtime and maintenance costs. Flexible Design Can accommodate axial and radial shaft movements without special precautions.

10 HYDROSTATIC FEED Hydrostatic Feed is a method of introducing clean filtered water directly into the seal interface to achieve optimum performance. It can be applied to any of the S M Seals range of shaft seals. For effective operation the hydrostatic feed water should be at a higher pressure than the water being sealed. The level of filtration plays an important part in achieving optimum performance and S M Seals can supply a system for filtration of either station cooling water or penstock water. The sketch shown shows a typical example of a S M Seals hydrostatic control system, we can also incorporate an automatic hydrocyclone into this system. Alternatively we can advise customers who may wish to provide their own systems. Benefits Longer Life The injection of a continuous pressurised supply of clean water directly into the centre of the running faces ensures improved lubrication and cooling and also excludes abrasive particles. Improved Performance The use of hydrostatic feed enables higher speeds and pressures to be catered for due to improved lubrication and cooling. Effective Air Sealing Hydrostatic feed water ensures lubrication and cooling of the seal faces on pump turbines when operating in Blow Down condition for pump start or synchronous condenser mode.

11 Vacuum Sealing On turbines subject to either occasional or continuous vacuum conditions hydrostatic feed ensures lubrication and cooling of the seal running faces at all times. Energy Saving Improved lubrication and cooling reduces friction losses in the seal.

12 The SMS Inflatable Static Seal can at the customers request be incorporated into any SMS seal design and can be either Air or Water Pressure Activated. Should any maintenance be required on the main shaft seal the static seal can be activated, allowing access to the shaft seal, without the necessity of dewatering the Turbine. In certain applications it also allows replacement of the wearing face without dewatering the machine, therefore reducing downtime and providing a cost effective solution. Three active seal faces ensure minimal leakage during Static Seal operation. Valves and interlocks incorporated into the control system should prevent inadvertent activation during normal machine operations. Maximum and Minimum activation pressures are dependant upon application and control configuration.

13 Head Office and Design Centre North and Central American Office S M SEALS LTD RESOURCE INTERNATIONAL Topstock House St Augustine 27B North Street Florida Crewkerne USA Somerset TA18 7AL United Kingdom Tel: +44 (0) Tel: +1 (904) Fax: +44 (0) Fax: +1 (904) info@smseals.com solo@se.rr.com sales@smseals.com technical@smseals.com Asian Offices ADVANCED MATERIALS & TRIBOLOGY 114 Sundaram Industrial Estate Off BKSD Marg, Next to USV Ltd Deonar Mumbai India Tel: +91 (0) / Fax: +91 (0) / apexhimanshu@yahoo.com