case studies Archives - Page 2 of 2

12th June 2018 by Iseki Iseki

DEERING, ALASKA, USA

Village Safe Water, Alaska

Client: Village Safe Water, Alaska
Country: ALASKA, USA
Length of Pipe: 1.68 km
No. of Valves: 53
Volume of Flow: 8 litres / second
Specialist Feature: Operation in arctic conditions

Deering is situated 800km North West of Anchorage. This small village consisting of some fifty houses, a school and a laundry sits on a narrow peninsular with the sea on one side and a small river estuary on the other. There are no roads leading to or from Deering so approach to the village has to be made by sea or air. A vacuum system was chosen to serve this village because of its versatility, ease of installation and its ability to transport the relatively low flows of sewage from the individual properties at high speed through small bore pipes to the vacuum collection station without the danger of the sewage freezing. The foam insulated polyethylene pipes were installed just above the permafrost. Glycol trace heating was installed to the foam, this is designed to stop the pipes freezing during the winter months when the temperatures can get as low as minus 50°C.

The electric supply to the village is provided by a small generator, so a new generator dedicated to supplying the power required by the vacuum system was also provided. The installation of the system commenced in 1997, however, work quickly came to a stop when the civil contractor uncovered the remains of an old village, many artefacts were discovered some inches below the surface during the excavation of the pipe trench. A team of archaeologists quickly set up a laboratory in Deering to examine and preserve the artefacts. This was a very slow process which resulted in no further pipe work being installed that year. In 1998 work recommenced but once again progress was slow.

Vacuum Pipework
Over 1500m of Polyethylene pipe were installed. Pipe sizes ranging from Ø90mm to Ø160mm.

Summary
As a result of the vacuum system being installed the residents of Deering can now take their drinking water from the river without the danger of it being contaminated by sewage which was previously disposed of by hand into the sea around the estuary.

Possible Applications of Iseki Redivac’s Vacuum Technology
Rural community sewerage schemes
Industrial developments
Supply bases
Housing developments / compounds
Hazardous waste collection
Airports & military installations
Beach developments
Remote villages

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Deering Main road

Vacuum Station

Toilet with Iseki Vacuum Valve installed in sump

12th June 2018 by Iseki Iseki

Zayed Sports City Stadium, UAE

Client: Abu Dhabi Municipality
Country: United Arab Emirates
Length of Pipe: 300 m
No. of Valves: 36
Volume of Flow: 50 litres/second
Specialist Feature: Collects sewage from 70,000 seat stadium

Situated in the heart of Abu Dhabi the Capital City of the U.A.E. is the prestigious Zayed Sports City Stadium, the venue of international sporting events and competitions. Guided by the belief of H.H. Shaikh Khalifa Bin Zayed, the Crown Prince in 1974 the complex was completed by 1980 and has a seating capacity of 70,000 spectators.

The Stadium plumbing and waste water collection system lies deep within the structure and finds its way into a gravity collector sewer constructed in a gallery around the perimeter of the stadium, at depths exceeding 4 metres.

Located in saline water conditions with an upper surface just below the ground level, the prospects of relaying the sewer in such ground conditions was a daunting if not impossible task. An alternative consideration to reline the damaged pipes was also very difficult primarily due to severe access problems.

Iseki offered the vacuum technology as a solution. The proposal was to intercept the incoming gravity flows above ground in collection sumps and via a vacuum interface valve and ring main collect the sewage in a steel vessel located in the vacuum station cleverly positioned beneath the seating.

Careful design ensured comprehensive operation of the system both under maximum design conditions of 70,000 spectators attending the 1994 Arab Gulf Football Tournament and normal day to day attendance with the very small flows generated by the employees at the complex.

The system whilst being fully automatic is monitored via telemetry in the Town Drainage central control complex thus alleviating maintenance costs but ensuring efficient and continuous working. With the installation now totally above ground future inspections or replacements will be particularly straight forward and cost-effective.

Vacuum Pipework
200 mm diameter polyethylene pipework around the service gallery connecting into the vacuum station

Vacuum Station Equipment
3 No rotary vane vacuum pumps each rated at 400m³/hr

2 No dry well discharge pumps each rated at 50 l/sec duty assist

Vacuum collection vessel volume – 16 m³ fully protected with epoxy coating and tested to Lloyds certification

Motor control cabinet – fully automatic with switchable programmable PLC. All pumps start in rotation and all conditions are remotely monitored via station telemetry in the Town Drainage dept central control which minimises personnel attendance.

Bespoke valve monitoring system which monitors the open / closed mode of each interface valve located around the stadium, the data is transmitted onward to central control such that each point of discharge within the Stadium can be individually observed.

Exhaust gases are filtered by passing them through an activated carbon filtration unit and are finally discharged via a vent stack to the rear of the stadium.

Summary
This project demonstrates the unique versatility and Engineering flexibility of the technology in providing solutions to difficult drainage problems.

Possible Applications of the Vacuum Way
Rural community sewerage schemes
Industrial developments
Supply bases
Housing developments / compounds
Hazardous waste collection
Airports & military installations
Beach developments
Remote villages

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Stadium

Interface valve mounted in wall cabinet.

Collection Sump

Discharge pump and pipework

Black PE Vacuum pipe visible in roof prior to cladding

12th June 2018 by Iseki Iseki

All England Lawn Tennis Club, Number 1 Court, Wimbledon

Client: All England Lawn Tennis Club
Country: UK
Length of Pipe: 600 m
No. of Valves: 54
Volume of Flow: 120 litres/sec
Specialist Feature: Roof rainwater drainage. Large invert lifts from gutter to vacuum ring main.

As part of an on-going development of the excellent facilities at Wimbledon, the All England Lawn Tennis Club commissioned the design and construction of a new Number 1 Court. The chosen design included a symmetrical cantilevered roof with no supporting columns within the seating area, thus ensuring that all spectators will be able to enjoy unobstructed views of the tennis. However, this aesthetically pleasing design led to the problem of draining the stormwater since it was not desirable to have downpipes from the high-level gutter to ground level.

Following on from the success of the Centre Court drainage system the designers looked to Iseki to construct a new Roof Drainage system for the new Number 1 court. The Vacuum Way proved an ideal choice, with the interface valves located high in the roof space, draining both the inner and outer gutters via dual ring mains back to a single collection station, together with the system’s ability to cope with a full range of rainfall conditions.

The Interface Valves open and close automatically as the flow dictates and are switched off during play on the court, thus ensuring complete silence for the players. The complete system is constantly scrutinised via an Iseki valve monitoring system to check that valves and equipment are working fully and efficiently during the championships and automatically for the rest of the year.

No. 1 Court under construction

Vacuum ring mains

Vacuum Pipework
Vacuum sewers in polyethylene, sized from 90mm to 200mm diameter, with electro-fusion joints.Vacuum Station Equipment
3 liquid ring vacuum pumps each rated at 925 m³/hr duty/assist/assist (Nash) 3 No dry well discharge pumps each rated at 60 l/sec duty/assist/assist (Sihi) 25m³ Vacuum collection vessel fully protected and tested to Lloyds certification Motor control cabinet – fully automatic with programmable PLC. All pumps start in rotation and all conditions are remotely monitored via building management system to a central control office, which minimises personnel attendance. Bespoke valve monitoring system which monitors the open / closed mode of each interface valve located around the roof, such that each valve within the roof area can be individually observed from the collection station. This data is also passed through to the control office. Exhaust gases from this system are exhausted to atmosphere under the stands, whilst the water is discharged via a pressure main to the storm water drain in the road outside.

Summary
This project demonstrates the versatility of The Vacuum Way in its use for collecting effluents other than sewage. This roof had the difficult geometry of the gutter being some metres below the crown of the roof, which was where the main drainage pipes had to run for aesthetic reasons. This meant that a powered system of some kind had to be used and Iseki were able to offer the most cost effective and efficient solution.Possible Applications of the Vacuum WayRural community sewerage schemes Industrial developments Supply bases Housing developments / compounds Hazardous waste collection
Airports & military installations Beach developments Remote villages

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Vacuum Interface Valve suspended in roof

Valve Monitoring panel located in pumping station

Vacuum ring mains

Vacuum Ring Main suspended from roof structure

Narrow Streets unsuitable for conventional gravity sewerage system

12th June 2018 by Iseki Iseki

TAI WAI & TAI PO, Hong Kong

Client: Government of Hong Kong
Country: Hong Kong
No. of Vacuum stations: 2
No. of Valves: 110
Volume of Flow: 40 litres/second
Specialist Feature: Vacuum sewers installed in narrow streets that restricted access.

When the villages of Tai Wai and Tai Po in the New Territories of Hong Kong urgently required a replacement for their old septic tanks with a proper sewer system they were faced with a serious problem. They needed a completely new sewerage network, but the very narrow streets would not allow for trench digging machinery and conventional large bore sewage pipes simply could not facilitate the complexity of pipe runs required. Therefore a conventional gravity system could not be used. Iseki Redivac provided the answer. The Iseki Redivac technology only requires shallow narrow trenches to be dug enabling the connection of approximately 400 buildings. Connection to some of the more remote properties was a challenge to the designers and construction teams with each property seeming to present more obstacles and needing tighter connections. The principle of the system is that when sufficient effluent has entered the valve chamber it ‘triggers’ an Iseki Redivac interface valve which introduces vacuum to the chamber drawing the effluent into the sewer pipe at velocities of around 6 meters/second. At this speed, the sewers can accommodate tight bends, curves and even inclines whilst providing a self-cleaning, low maintenance system.

Vacuum Pipework
Vacuum sewers in PN10 polyethylene pipe sized from Ø90mm to Ø160mm with electro-fusion joints.

Vacuum Station Equipment
Two vacuum stations each operate with two rotary vane vacuum pumps. The two sets of pumps in Tai Wai and Tai Po stations are rated at 630 m³/hr and 250m³/hr respectively.
The sewage discharge pumps installed are centrifugal screw type pumps supplied by Hidrostal. Both vacuum vessels are fully coated inside and out as well as being certified to Lloyd’s standards. The motor control centre is fully automatic with PLC logic control. All pumps start in rotation and all conditions are monitored with a data logging system.

Summary
For Tai Wai vacuum technology was the only option available to the designers, as the trenches had to be dug by hand. At Tai Po the substantially lower installation costs and the need for fewer pumping stations made the Iseki Redivac system the preferred choice based on cost efficiency alone. The two sewer systems were installed over ten years ago and are still providing a reliable efficient service to the community.

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Narrow Streets unsuitable for conventional gravity sewerage system

Narrow Passageways

Interface Valve in bespoke chamber

Vacuum Vessel being installed

8th June 2018 by Iseki Iseki

UNIVERSITY CITY, Sharjah, UAE

Client: Sharjah Municipality
Country: United Arab Emirates
Length of Pipe: 44 km
No. of Valves: 410
Volume of Flow: 4 stations each 50 litres/sec
Specialist Feature: Versatile system that was designed, built and commissioned in 6 months

The Sheikh perceived the need for a University in the Emirates and he personally took on the task of coordinating the project. However this created a tall order with a time scale such that when Iseki were invited to offer a solution only 20 weeks remained before the planned opening. This fast track approach rendered the use of a vacuum sewerage system a must. Iseki Engineers designed the scheme on site ahead of construction. The use of local suppliers in Sharjah enabled the HDPE pipe to be manufactured to the required quality and delivered to site, allowing pipe laying to proceed immediately. Local companies were also used to manufacture the large vacuum vessels, whilst the balance of equipment, such as pumps, was shipped out from Europe. A tall order, delivered on time with the versatility of Iseki personnel and technology.

Vacuum Pipework
Vacuum sewers in PN10 polyethylene sizes from Ø90mm – Ø200mm with electro-fusion joints

Vacuum Station Equipment
Four stations each operating with three rotary vane vacuum pumps each rated at 400m³/hr (Busch) together with two dry well discharge pumps each rated at 50 l/s (full duty)Vacuum collection vessel 25m³ fully protected for Middle East conditions and tested to Lloyds certification. Motor control cabinet fully automatic with a PLC. All pumps start in rotation and all conditions are monitored with a data logging system.

Bespoke vacuum interface valve monitoring system which monitors the open/close mode of each valve at all locations around the project.

Summary
This sewerage system could only have been designed and built within the allocated time span using ‘The Vacuum Way’ An achievement we are proud to be a part of.

Applications for Iseki Redivac’s Technology
Rural community sewerage schemes
Industrial developments
Supply bases
Housing developments / compounds
Hazardous waste collection
Airports & military installations
Beach developments
Remote villages

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University of Sharjah

Avenue

Vacuum Vessel

Electrical Control Panel situated in the Vacuum Station

Pipe laying in progress

Vacuum Station building in keeping with the local architecture

8th June 2018 by Iseki Iseki

ROSEDALE ABBEY VILLAGE England

Client: Ryedale District Council
Country: UK
Length of Pipe: 2000 m
No. of Valves: 28
Volume of Flow: 10 litres/second
Specialist Feature: Steep gradients, rocky ground, stream crossings.

The picturesque village of Rosedale Abbey lies deep within the North York Moors National Park – an area of great natural beauty and environmental sensitivity. Very popular with holidaymakers, the village contains peaceful caravan parks and several restaurants and pubs. The population varies greatly between winter and summer.

The village is situated alongside the river Seven and is in a steep sided valley. In the past, inadequate sewerage within the village meant that the risk of polluting the river was always present, particularly so in the summer months.

Having made the decision to install a mains sewerage system to serve the village, Ryedale District Council designers were faced with some difficult problems to overcome. The river and a tributary stream had to be crossed by the sewers and the environmental impact of the construction work had to be kept to an absolute minimum. This meant that fixing pipes to the existing bridges was not acceptable – the pipes had to cross under the deeply cut stream and river.

To use conventional sewerage techniques would have meant pumping stations at each crossing together with some deep trenching works in difficult ground. Iseki were asked to assess the possibility of using The Vacuum Way and were able to offer a cost-effective and well engineered sewerage system. This enabled the environmental impact to be kept to a minimum with shallow, narrow trenches and a single pumping station located away from the attractive village centre.

Vacuum Pipework
Vacuum sewers in polyethylene, sized from 110mm to 160mm diameter, with electro-fusion joints.

Vacuum Station Equipment
2 liquid ring vacuum pumps each rated at 370 cubic metres/hr.

2 No dry well discharge pumps each rated at
10.5 l/sec duty-assist.

Vacuum collection vessel volume 4.5 cubic metre fully protected with suitable paint and tested to Lloyds certification

Motor control cabinet – fully automatic with programmable PLC. All pumps start in rotation and all conditions are remotely monitored via station telemetry in a central control office, which minimises personnel attendance.

Bespoke valve monitoring system which monitors the open / closed mode of each interface valve located around the village, such that each valve within the village can be individually observed from the collection station.

Exhaust gases are filtered by passing them through a biological filtration unit situated close to the collection station which is within the sewage treatment works site

Summary
The ‘Vacuum Way’ enabled the river and streams to be crossed without the need for separate pumping stations. The shallow trenches offered specific construction advantages on the steep streets of the village. The system is sufficiently flexible to cope well with the wide seasonal variety in sewerage flows.

Possible Applications for Iseki Redivac’s Technology
Rural community sewerage schemes
Industrial developments
Supply bases
Housing developments / compounds
Hazardous waste collection
Airports & military installations
Beach developments
Remote villages

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Vacuum sewer crossing river

Vacuum Station building in keeping with the local architecture

Crossover connection

Cost effective solutions to many difficult drainage problems

8th June 2018 by Iseki Iseki

CSORNA, HUNGARY

Client: Mestermernok
Country: Hungary
Length of Pipe: 34km
No. of Valves: 420
Volume of Flow: 24 litres/second
Specialist Feature: Flat terrain and high water table

The village of Csorna is situated some 150km north of Budapest and 30 km east of the nearest town, Gyor. The landscape in and around Csorna is flat with a high water table making a vacuum sewerage system an obvious choice due to the ground conditions. The system was installed during 1997 by Hungarian civil contractor Mestermernok. The day to day running of the vacuum system is the responsibility of the local water company operating from a nearby sewage treatment works. A computer link between the vacuum station and treatment works enables the maintenance crew to monitor and control the vacuum system’s operation from their control room at the treatment works.

Mestermernok have installed equipment to the main control panel which allows the PLC logic to be reprogrammed from the town of Gyor via use of a telephone/modem link. The Csorna vacuum system is very efficient and economical to operate with an electricity consumption of less than 0.5kwh per cubic metre of sewage collected.

Vacuum Pipework
There are some 34km of vacuum sewers in PN10 polyethylene pipe from Ø90mm to Ø160mm with electrofusion joints laid at an average depth of 1.2m.

Vacuum Station Equipment
22m³ steel horizontal vacuum vessel.

Three Nash SC4 liquid ring vacuum pumps each producing some 700m³/hr. The vacuum pumps operate on a duty/assist/assist basis.

Two dry well discharge pumps operating on a duty/ standby basis each with a capacity of 24l/s.

Control panel with programmable PLC which controls all pump operations and automatic recovery systems to assist with the efficient running of the vacuum system.

Valve Chambers
The valve chambers (designed by civil contractor Mestermernok) were constructed from pre-cast concrete rings complete with conical base unit and intermediate landing platform. 420 chambers have been installed to date serving some 1100 houses making the vacuum system one of the largest in Europe.

Summary
The village combines difficult geographical conditions – flat land with a high water table and covering many square kilometres. Many conventional gravity pumping stations would have been required whereas only one vacuum station was needed allowing minimal disruption to the village and providing the most cost-effective solution.

Applications for Iseki Redivac’s Technology
Rural community sewerage systems
Industrial developments
Supply bases
Housing development/compounds
Hazardous waste collection
Airports & military installations
Beach developments
Remote villages

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Village of Csorna

Vacuum Station at Csorna

Liquid Ring Vacuum Pumps

Valve Chamber Inspection

8th June 2018 by Iseki Iseki

CHAPPES, FRANCE

Client: Communes de Chappes
Country: France
Length of Pipe: 3000 m
No. of Valves: 50
Volume of Flow: 3 litres/second
Specialist Feature: River crossing

Situated approximately 150km south east of Paris, the village of Chappes is near the town of Troyes in the beautiful Champagne region. The village was without a mains sewerage system and relied on septic tanks for the disposal of sewage. Communes de Chappes made the decision that a sewerage system should be installed to serve the village in order to avoid the pollution of the River Seine and to eliminate other environmental contamination caused by inefficient or dysfunctional septic tanks.

The nearby village of Fouchere was also in the process of installing a sewerage system and had chosen Iseki Redivac’s technology as the most cost-effective solution. After consultation with Iseki Redivac and comparing the installation cost of vacuum and gravity sewers, the vacuum way was chosen as the most suitable option. Not only was the vacuum system easier and cheaper to install but the remarkable capabilities of the technology meant that only one pumping station was required.

The River Seine runs through the middle of the village and conventional sewers would require at least two main pump stations and many lift stations to serve the village. Iseki Redivac’s engineers were able to design the sewer network so that the sewer main was able to cross the river by attaching the protected pipe to the underside of the bridge. Such was the effectiveness of the design and quality of construction that the completed vacuum sewerage system has proved very reliable and has exceeded the initial performance parameters.

Vacuum Pipework
Vacuum sewers in polyethylene sized from Ø90mm to Ø160mm with electro fusion joints.Vacuum Station EquipmentTwo rotary vane air cooled vacuum pumps with a capacity of 200m³/hr.Two dry well discharge pumps rated at 5l/s, duty and standby.
Vacuum vessel has a 4m³ volume and is epoxy coated inside and out and tested to Lloyds Certification. The motor control cabinet is fully automatic with a programmable PLC. All pumps start in rotation. The valve monitoring system which monitors the open/closed mode of each interface valve located around the village can be individually observed from the vacuum station.

Exhaust gases are filtered by passing them through a Biological Filtration Unit situated adjacent to the vacuum station.

Summary
Poor ground conditions, challenging topography, river crossings and the need for installation to take place over a short time span, causing minimal impact to the normal life of the village, made Iseki Redivac the only realistic choice.

Applications for Iseki Redivac’s Technology
Applications for Iseki Redivac’s Technology
Rural community sewerage systems
Industrial developments
Supply bases
Housing development/compounds
Hazardous waste collection
Airports & military installations
Beach developments
Remote villages

Download this Case Study as a pdf

Vacuum Sewer Main crossing the river

Vacuum Sewer attached to the bridge abutment

Trench with vacuum pipe, valve chamber and monitoring cable

Chappes, France

Shallow vacuum pipework entering station

7th December 2017 by Iseki Iseki

ADDCAP OFFSHORE BASE, ABU DHABI, UAE

Client: ADDCAP
Country: United Arab Emirates
Length of Pipe: 3000 m
No. of Valves: 32
Volume of Flow: 10 litres/second
Specialist Feature: Design allows for on-going development and expansion of base facilities

Vacuum Station

Abu Dhabi Drilling Chemicals and Pipes are suppliers of materials to the oil and gas industry. Following the decision to move from their island base a few miles off the coast, a new site was selected on the mainland close to Abu Dhabi city. This new supply was to be located on a flat low lying area of desert sand adjacent to the Gulf. To be built on the new site was a central office block together with storage facilities, with warehousing that would develop as demand required. Provision was to be made within the vacuum sewer network design for the future addition of an accommodation block for employees on the base.The site measured 1km by 1km and was flat with saline ground water at approximately 1meter deep. Be-cause of the widely spaced buildings and the poor ground conditions, a conventional sewerage system would have been expensive and hard to install. Also, with the development taking place over a number of years, a large degree of flexibility was required such that changes to layout and flow patterns could be ac-commodated by the system.

GRP Collection Sump with concrete anti-floatation collar

Vacuum Pipework
The polyethylene pipework around the Base ranges in size from 90mm to 160mm diameter.

Vacuum Station Equipment
2 No liquid ring vacuum pumps each rated at 370 cubic me-tres/Hr (Nash) acting in duty/assist configuration, served by a water cooling unit to ensure peak efficiency.
2 No dry well discharge pumps each rated at 10 l/s duty/standby
Vacuum collection vessel volume – 16 cubic metre fully pro-tected with epoxy coating and tested to Lloyds certification
Motor control cabinet – fully automatic with programmable PLC. All pumps start in rotation and all operating conditions are monitored via station telemetry.

Bespoke valve monitoring system which monitors the open / closed mode of each interface valve located around the site.
Exhaust gases are filtered by passing them through an activat-ed carbon filtration unit and are finally discharged outside of the collection station building.

Shallow vacuum pipework entering station

Summary
The Vacuum Way proved the ideal solution – pipes were in-stalled at shallow depths, largely above the sea water table and the inherent flexibility of the system in terms of future de-velopment was greatly appreciated by the Client.

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