TURBINE SEAL: AXIAL TYPE DESIGN

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Abraham Bradford
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TURBINE SEAL: AXIAL TYPE DESIGN Our axial type seals are specifically designed for application to hydroelectric turbines and large water pumps for sewage handling, filtration, irrigation, and more.

systems. Depending on the turbine s operating conditions, many custom arrangements can be used.

1 TURBINE SEAL: AXIAL TYPE DESIGN Our axial type seals are specifically designed for application to hydroelectric turbines and large water pumps for sewage handling, filtration, irrigation, and more. Our axial type seals are self aligned, balanced split face seals capable of withstanding the heavy torques, pressures, shaft movements (radial and axial) and thrusts associated with such shaft systems. Depending on the turbine s operating conditions, many custom arrangements can be used. The sealing action takes place between two mating rings; one stationary, the Sealing Ring, the other rotating with the shaft, the Seat Ring. The axial direction of the sealing action prevents damage to the turbine or pump shaft, since the wear is taking place between the Seat and the Sealing Rings, and not on the shaft. The Sealing Ring is held in contact with the Seat Ring by a spring force and the hydraulic force of flushing water. These properties balance the seal at all times.

2 TURBINE SEAL: AXIAL TYPE DESIGN A flow of clean water, free of abrasive particles must be maintained throughout the seal, to provide cooling, lubrication and to reduce wear of the sealing surfaces. Water should be filtered to ensure that impurities larger than 25 microns are removed, in order to prevent abrasives particles entering from under the seal. The clean water supply must be at a higher pressure than the water pressure under the seal. It is recommended to install an automatic differential pressure system with the water supply, maintaining a constant pressure difference above that of the pressure under the seal. On certain models of our seals, the water is injected directly between the mating faces. By controlling the seal water flow in the annular profile between the faces provides the benefits of a double seal since it allows control of the seal s environment through cooling, lubricating and cleansing, as impurities are prevented from entering in between the mating faces. All of our seals include an assembly kit (consisting of: eyebolts, jacking screws and hex keys for use during assembly or disassembly of the housing parts), an o-ring splicing kit, flange sealant, silicone grease, a piping connection identification plate and three copies of the installation, maintenance and operation manual. In order to regulate the pressure differential between the shaft seal and the turbine, a seal water control panel complete with an automatic differential pressure regulator can be supplied with each seal. The positive pressure differential is necessary to prevent abrasive particles from entering the seal chamber. Operational Limits Max. Turbine operating pressure: Max. Recommended barrier water pressure: Recommended water filtration: Radial shaft dislocation: Axial shaft dislocation: Shaft /sleeve finish: 1379 kpa (200 psi) kpa (3-10 psi) above turbine pressure 25 microns ± 1.3 mm (0.06 ) ± 3-25 mm ( ) 63 RMS

Depending on the pressure under the seal, two or more carbon segmented sealing rings are required. This seal is reliable, simple to install, selfadjusts and easy to operate and maintain.

3 TURBINE SEAL: RADIAL TYPE DESIGN Radial type seals are used in hydroelectric turbines, pumpturbines and large pumps. The primary purpose of a mechanical radial shaft seal is to maintain a near watertight seal between the turbine shaft and the head cover. Depending on the pressure under the seal, two or more carbon segmented sealing rings are required. This seal is reliable, simple to install, selfadjusts and easy to operate and maintain. All of our radial type shaft seals are fully split or nonsplit and specifically designed for hydropower generating turbines. The seal can be custom designed and adapted to the existing turbine configuration and specification in order to meet the operating requirements. For small shaft diameters, these seals can be designed with anti-rotation pins positioned in the cover and in the lower chamber ring to maintain a low seal profile. For easier installation we recommend the use of an intermediate ring with the stop pins located between the two sealing rings in order to facilitate installation. If required, an inflatable seal can be supplied to allow maintenance without dewatering the turbine. A basic turbine seal consists of a base ring and a cover ring forming the cavity that houses the sealing rings. The cover ring is secured to the base ring that, in turn, bridges the gap between the turbine shaft and the head cover and also serves to house the inflatable seal (if required). The cover ring can also be designed to act as a reservoir to accumulate water on top of the seal to prevent a dry running condition of the top sealing ring in the event that the turbine is operating under vacuum conditions. Each sealing ring assembly consists of overlapped and interchangeable carbon segments, compression springs and garter springs. The carbon segments are positioned around the shaft to perform the sealing function. The sleeve is split into half rings or quarter sections. The sealing area of the sleeve is machined to a high precision surface finish. The sleeve rotates with the shaft by means of drive screws or a clamping system. A flow of clean water free of abrasive particles must be maintained throughout the seal to provide cooling and lubrication to reduce wear of the sealing surfaces. Water should be filtered to ensure that impurities larger than 25 microns are removed. In order to prevent dirt from entering the seal from below, the clean water supply must be at a higher pressure than the water pressure underneath the seal.

TURBINE SEAL: RADIAL TYPE DESIGN All of our seals include eyebolts and jacking screws for use during assembly or disassembly.

A copy of the installation, maintenance and operation manual are also provided with the seal.

each seal. The positive pressure differential is necessary to prevent abrasives particles from the river entering the seal chamber. Model Max. Turbine operating pressure: Max.

4 TURBINE SEAL: RADIAL TYPE DESIGN All of our seals include eyebolts and jacking screws for use during assembly or disassembly. The seals also come with Hex keys for assembly of the housing components, an o-ring splicing kit, flange sealant, silicone grease and a piping connection identification plate. A copy of the installation, maintenance and operation manual are also provided with the seal. In order to regulate the pressure differential between the shaft seal and the turbine, a seal water control panel complete with an automatic differential pressure regulator can be supplied with each seal. The positive pressure differential is necessary to prevent abrasives particles from the river entering the seal chamber. Model Max. Turbine operating pressure: Max. Recommended barrier water pressure: Recommended water filtration: Radial shaft dislocation: Axial shaft dislocation: Shaft /sleeve finish: TYPE F200, F201, F210, F kpa (30 psi) kpa (3-5 psi) above turbine pressure 25 microns ± 1.5 mm (0.06 ) No restrictions 32 RMS TYPE F310, F311, F kpa (100 psi) kpa (3-5 psi) above turbine pressure 25 microns ± 1.5 mm (0.06 ) No restrictions 32 RMS

5 SEAL AIR AND WATER CONTROL PANEL The seal water control panel is designed to regulate the flow and pressure of water supply to the seal. The support plate is made from painted steel, polished aluminum or a stainless steel plate.

S PARE P ARTS AND A CCESSORIES Fugesco can supply spare parts for your

Our engineering department will study tour existing seal in order to

In many cases we can improve on actual performance by suggesting our

competition with a better surface finish, interchangeability without

With the precision of our manufacturing our sealing rings obtain better

We can increase the wear allowance up to 30 % in some cases, without extra

Pressure Rings We are equipped to roll any diameter of single or double

6 S PARE P ARTS AND A CCESSORIES Fugesco can supply spare parts for your existing turbine seals. Our engineering department will study tour existing seal in order to retrofit any existing technology. In many cases we can improve on actual performance by suggesting our solution at the best possible price without changing your actual configuration or seal housings. Sealing Rings We can reverse engineer any existing design from our competition with a better surface finish, interchangeability without markings or lapping. With the precision of our manufacturing our sealing rings obtain better sealing with lower leakage during initial start-up and regular operation. We can increase the wear allowance up to 30 % in some cases, without extra leakage. Pressure Rings We are equipped to roll any diameter of single or double pressure ring segments for any existing designs. Garter- Compression springs Since the springs are manufactured in-house, we can easily control our product for better materials, necessary tension, faster delivery terms and better prices. Electronic or mechanical wear indicator Fugesco has mechanical and electronic wear indicators for use in wet and dry applications.

Bulletin /06/2012 Supersedes 10/23/00. Installation of John Crane Type 73 Inflatable Mechanical Seal. Page 01 of 10

Bulletin /06/2012 Supersedes 10/23/00. Installation of John Crane Type 73 Inflatable Mechanical Seal. Page 01 of 10 01 of 10 1. Carefully read all instructions and notes before installation. 2. Bench Pre-assembly: a. Insert the support ring (item #1) inside the inflatable boot (item #2) to form inflatable seal assembly