This section highlights our expertise in pool plant water treatment. Scroll down the page to see how we can help, or select a section from the following:
New Filters / Valves and Pipework | Filter Refurbishment / Relining / Manways | Filter Media Changes | Bulk Chemical Storage / Bunds & Chemicals | Circulation Pumps and Flow Meters | Inverter Drives | Plate Heat Exchangers | Integrated Control Systems / Energy Savings | Pool UV Systems | Chemical Dosing and Control Systems
New Filters / Valves and Pipework
We specialise in the installation and replacement of all types of swimming pool filters and pipe work and offer a complete package from design through to installation and commission. All our filters are “deep bed” and are selected to provide medium rate filtration.
We can offer replacement filers including GRP, Steel, Laminated and Split filters (where limited access is available within the plant room).
Our comprehensive range of GRP filters are manufactured with a liner employing special resins which form a watertight, anti-corrosive barrier, giving a high chemical resistance to chemicals.
An outer fibre-glass shell is then applied to the liner, using the bobbin winding process: The filter standard features are below.
- Polyester shell linings
- Ø50mm Polypropylene arm collectors
- PVC distribution pipe work
- Automatic air relief valve
- Bolt down lid Ø400mm
- Sand and water drain port
- Complete with pressure gauge panel
Our mild steel filters are manufactured to BS5500CAT3/1982 and have 8mm thick plate on the shell and 12mm thick plate on the dished end. The filters come complete with 600mm side and top mounted access Manways with bolted lids.
The filter internals have an upper bell mouth system and a lower lateral set manufactured from PVC connected to a central PVC header the underdrain system supported on a concrete base. Filers can be manufactured in various diameters depending on the application required.
The filters are manufactured from fibreglass and polyester resin; the internal pipework and distribution system is manufactured from PVC and polypropylene. 1.0 metre media bed depth and lateral arm collector system are standard on all models. Its features and benefits include:
- High chemical resistance
- Suitable for salt water pools
- Smooth laminate outer shell providing a durable, robust finish.
- Lateral collector arms in polypropylene
- Ø 400mm bolted top sand charge lid
- Ø 200mm sand service port
- Water drain
- Manual air purge
- 1.0 metre media bed depth
- 2.5 bar max operating pressure
- 50ºC max working temperature
Plant rooms can be congested and have limited access and when filters fail and require replacements it is not possible to get filters into the plant room.
We can offer a solution to this with our split filters which come in a variety of sizes from 1.2m to 1.8m diameter.
The Fibreglass pressure tanks have a number of major advantages over steel tanks including:
- Durability: Fibreglass vessels have a mechanical and chemical resistance superior to steel, plus fibreglass does not rust or corrode and is able to withstand damage from many types of water treatment chemicals.
- Lightweight: Fibreglass tanks weigh only one third that of steel vessels, whilst maintaining the same level of strength and makes them easy to ship and install.
- Easy to Maintain: Once installed they are virtually free of maintenance or repairs. This compares with steel vessels which require the anti-corrosive coating to be maintained periodically, with certified welders required to make repairs to the lining with epoxy coating.
They can be delivered in two parts and assembled on site in the plant room. The two halves seal perfectly, using double o’ring and held together by a flange using bolt and nuts. The filter is specifically designed to fit through existing standard size plant room doors.
We can carry out installation and repair of PVC and ABS pipe work our pipe work range in sizes from ½” – 12”. Cast iron pipework can also be replaced with PVC.
We can install a range of valves from 2” to 10” diameter.
The Valves are wafer butterfly type with cast iron bodies, stainless disc and EPDM seals.
Filter Refurbishment / Relining / Manways
Sterling offer a complete package for the refurbishment of filters. Our services include the removal of existing media by vacuum tanker, shot blasting and relining the internal surfaces of steel filter vessels, and re lining using the Corroless solvent free 3-coat epoxy paint system.
We can also replace existing lateral and nozzle plates systems and header pipe work. We install new 600mmØ manways to comply with current confined space entry requirements.
Where multiple swimming pool filters are to be refurbished, this can take place in stages, allowing the pool to remain in operation whilst the refurbishment takes place.
Filter Media Changes
As standard we remove existing filter media from the vessels using our specialist vacuum tanker unit rather than manual removal. This method of media removal is quick, safe and helps to avoid unnecessary mess and difficulties that can be encountered with this type of work when carried out manually. Safety is of prime importance and this method of removal minimises the risk for this part of the works by removing the need for manual handling of the media to skips and reducing vessel entry requirements.
All redundant filter media is disposed off site to registered landfill sites only in accordance with current legislation. Our price allows for disposal costs. The filters are manually charged with the correct quantities of selected grades of Leighton Buzzard silica sand, which shall be limestone and clay free, or recycled glass. Delivery of media to site will be in 25 kg bags on pallets, in accordance with current EEC manual handling regulations / guidelines.
Leighton Buzzard silica sand (graded limestone and clay free) :
16/30 | 8/16
Graded gravel under beds:
20mm | 10mm | 6mm
ECO-GLASS-FILTER-MEDIA is an environmentally friendly alternative to traditional silica sand.
The media is made from glass recycled in the UK and therefore doesn’t involve the intrusive mining and use of a scarce resource. Going “green” however is no longer cost prohibitive and EGFM is comparable to the price of silica sand whilst improving performance and conserving natural resources.
Bulk Chemical Storage / Bunds & Chemicals
The use of bulk storage tanks as part of the chemical dosing systems are common in leisure centres and we can install a range of sizes of tanks manufactured in GRP or Polypropylene.
The tanks can be either delivered complete or where access is restricted can be built in sections on site.
We also install chemical dosing bunds, which can be designed to suit the size and application required.
Circulation Pumps and Flow Meters
The Pumps are generally Non self-priming, single stage end suction pumps for use on thin, clean water slightly contaminated, but without abrasives. Self-priming Pumps are available if required.
The pumps we offer for smaller applications are manufactured in Polypropylene and fibreglass complete with a Stainless Steel shaft and a Carbon Ceramic seal. The Impeller is manufactured from polypropylene and fibre glass and they have an IE2 Motor with IP55 classification waterproof sealing. These units generally come complete with an integral Strainer Box and Strainer Basket.
The Pumps we offer for larger applications have cast Iron housing and volute and a stainless steel shaft and come complete with Bronze Impellers and Seals for use on Chlorinated Pool water. The Pumps are connected to an electrical Drive motor via a Stainless Steel shaft. These units are generally, standalone pumps and require a separate Strainer Box and Basket to be installed in line with the Pump Suction.
All new motors installed after 2011 should be of Class IE2 Design. This classification of design should then increase to Class IE3 Design or class IE2 Design with a VSD by 2015 to comply with the new directive. Any Motor’s retrofitted should be to this new standard as part of the EuP (European) Directive on Electric Motors (EC640/2009) replacing the old Motor drives
Inverter Drives
Swimming pool halls are expensive to run, consuming large amounts of electricity. The high energy consumption is due to the large volume of water in the pool that continually needs to be circulated, heated, treated, filtered, topped up and replaced.
A 25 m pool can hold as much as a million litres of water. Additionally, the costs for space heating and ventilation are high. In a large hotel, the swimming pool can account for up to 10% of total energy costs.
Swimming pool running costs can be significantly reduced by as much as 50 percent with variable speed drives. These devices control the flow of swimming pool pumps to eliminate the energy waste that is common with conventional pump and fan control methods.
A small reduction in speed can make a big difference in energy consumption. A pump or fan running at half speed consumes only one quarter as much energy as a unit running at full speed. This is because the power required to run a pump or fan changes with the cube of the speed.
Inverter Drives
Swimming pool halls are expensive to run, consuming large amounts of electricity. The high energy consumption is due to the large volume of water in the pool that continually needs to be circulated, heated, treated, filtered, topped up and replaced.
A 25 m pool can hold as much as a million litres of water. Additionally, the costs for space heating and ventilation are high. In a large hotel, the swimming pool can account for up to 10% of total energy costs.
Swimming pool running costs can be significantly reduced by as much as 50 percent with variable speed drives. These devices control the flow of swimming pool pumps to eliminate the energy waste that is common with conventional pump and fan control methods.
A small reduction in speed can make a big difference in energy consumption. A pump or fan running at half speed consumes only one quarter as much energy as a unit running at full speed. This is because the power required to run a pump or fan changes with the cube of the speed.
Because many pump and fan systems run at less than full capacity for much of the time, variable speed drives can produce huge savings. If a 100 kW pump is throttled by 50%, for example, the investment in a variable speed drive will have a payback of only six months of continuous operation.
This will give, Significantly reduction in energy bills, a Rapid return on investment, Lower maintenance costs, and Substantial contribution to the environment by lower CO2 emissions and access to Carbon Trust loans.
The VSD’s (Variable Speed drives) are easy to retrofit to any motor / pump installation by our qualified engineers.
At night, the power to each pump can be reduced typically by some 50% which will only reduce the flow rate by some 20%, giving a flow rate and turn over of some 80% through the night-time period when the pool is not in use.
By cycling the pump between these day and night settings, energy consumption can be cut by nearly half, compared to running the pump continuously at full speed. Note that these figures are guidelines only. The actual settings Reduce pump speed when demand is low must be adjusted for each installation.
Because many pump and fan systems run at less than full capacity for much of the time, variable speed drives can produce huge savings. If a 100 kW pump is throttled by 50%, for example, the investment in a variable speed drive will have a payback of only six months of continuous operation.
This will give, Significantly reduction in energy bills, a Rapid return on investment, Lower maintenance costs, and Substantial contribution to the environment by lower CO2 emissions and access to Carbon Trust loans.
The VSD’s (Variable Speed drives) are easy to retrofit to any motor / pump installation by our qualified engineers.
At night, the power to each pump can be reduced typically by some 50% which will only reduce the flow rate by some 20%, giving a flow rate and turn over of some 80% through the night-time period when the pool is not in use.
By cycling the pump between these day and night settings, energy consumption can be cut by nearly half, compared to running the pump continuously at full speed. Note that these figures are guidelines only. The actual settings Reduce pump speed when demand is low must be adjusted for each installation.
Plate Heat Exchanger's
Sterling Hydrotech Limited offers a range of Plate Heat Exchangers to replace existing Heat Exchangers or old style Shell and Tube units.
Plate Heat Exchangers can be retrofitted on to the Main Circulation pipe work with Side Stream connections, whilst removing the old Heat Exchangers from site.
The Plate Heat Exchangers have high transfer coefficients, which offer high performance and optimum transfer of primary to secondary heat.
They also offer some degree of flexibility with the increase or decrease of the number of plates can offer an increase or decrease in the unit’s thermal properties.
These units still require expert design using the Primary Flow and Temperature parameters to offer the correct transfer of Heat to the Secondary Water Circulation flow and consequently the Water in your pool.
Integrated Control Systems / Energy Saving's
Sterling Hydrotech Ltd provides Integrated Systems linking Dosing Controls, Inverter Drives and UV systems to optimise efficiencies
Our UV systems are fitted with an energy saving ‘green switch’ power switching system. A monitor is used to measure the UV light dose and the power is optimised to meet this requirement. The installation of UV also reduces chemical and water usage.
New circulation pumps are fitted with high efficiency IE2 / IE3 motors to optimise power usage, 85% of the whole of life cost of a pump is the cost of power so using this type of motor reduces energy usage.
Pumps can also be linked to inverter drives which can be used to optimise the circulation flow during the day (typically saving 10% of power usage) and reducing the flow at night to 80% (typically saving 50% of power usage).
Inverter drives can be linked to dosing controllers to ensure that set dosing parameters are met in conjunction with the activation of the inverter drive.
We also fit mixers with timers to prevent unnecessary power usage.
Pool UV Systems
Upgrade your water treatment system with the introduction of UV
Chloramines in your pool water can cause unpleasant smells and even allergic reactions. Hanovia UV systems destroy them as well as dangerous waterborne micro-organisms including Cryptosporidium and Giardia. Your pool users will enjoy fresher-smelling, cleaner and more hygienic water, while you enjoy the reliability and effectiveness of a highly efficient water treatment system.
On commercial new build projects UV now considered as the norm and it can also be easily retro fitted into existing systems to bring the water treatment package into line with current best practice.
Apart from the advantages of its disinfection properties and the removal of chloramines it reduces chemical and water usage. The UV acts as the primary disinfectant and as a result of this the free chlorine level can be reduced from typically 1.5 mg/l to 0.8mg/l. A pool with reduced free chlorine is a much better environment for bathers and with significantly reduced chloramines there will be no ‘chlorine’ smell in the pool hall, reduced red eye and reduced potential for corrosion of the building associated with acid attack.
An energy efficient and environmentally responsible system
- Reduces the need for dilution
- Cuts the use of chemicals and avoids the need for routine shock dosing with chlorine
- Reduces requirements for free chlorine residual
- Creates no hazardous by-products
- Reduces corrosion of steel structures – minimising maintenance costs
Controlling costs
- Cuts your use of chemicals
- Requires little maintenance
- Reduces energy bills if you use the Power Switching option
- Reduces water bills, as there is no need to control combined chlorine levels by dilution and back washing
- Avoids repair and replacement costs from chemical wear and tear on pool fittings
The UV’s installed by us are specifically designed for use on pools. Sterling Hydrotech is an approved installation and service provider for Hanovia, ATG and Siemens and so we are able to install the unit and more importantly support it from a service and maintenance point of view.
The UV’s are selected to provide the required dose of 60mJ/cm based on a typical pool water with a UV transmittance of T10>98%
The UV is installed on full flow (not side stream) and is located in the outlet pipework after the sand filters. The circulation pipework will be modified to incorporate inlet / outlet isolating valves and a full flow bypass valve.
All UV’s installed by Sterling Hydrotech are commercial quality systems specifically designed for use on swimming pools incorporating medium pressure lamps for disinfection and chloramine reduction.
The systems incorporate typically the following:
- Stainless Steel Chamber with medium pressure lamp
- Control panel (Mounted on galvanised Unistrut)
- 20m interconnecting cable
- Energy saving “GreenSwitch” power switching system
- Automatic wiper system
- UV monitor
- Stainless steel in-line strainer
Pipework sections connected to the UV chamber will be stainless steel the remainder is UPVC.
Chemical dosing and control systems
Commercial swimming pools can vary enormously in design, size, turnover and bathing loads all of which need to be taken into consideration when choosing the specification and type of dosing equipment and controller for the pool.
Whether it is for a standard 25m x 13m pool or a 50m competition pool it is important an analysis of the incoming water is taken to ensure compatibility with the chemicals required for the dosing and PH correction equipment to be installed.
If you need to dose chlorine, hypochlorites, acids or alkalis, granular, tablet or liquid – we can provide the knowledge and advice to help you select the right equipment for your application.
Our experienced team can design and install a range of dosing equipment that will meet your requirements.
Sodium Hypochlorite (15% carbouy or 5% site generation from salt)
Calcium Hypochlorite (HTH)
A comprehensive range of dosing pumps, tanks, bunds and feeders to suite a wide range of applications.
- Sodium Bisulphate
- Hydrochloric Acid
- CO2
A comprehensive range of dosing pumps, tanks, bunds etc. to suit a wide range of applications.
PAC is a flocculent and is used to increase the filtration efficiency by causing small particles to bind together which can then be more effectively removed by the sand filters. Some of the small particles are bacteria etc, and in general terms the clarity of the pool water increases significantly as less suspended matter passes through the filters. Although chlorine will destroy bacteria and oxidize organic materials they remain in the water as a suspended solid and without PAC are too small to be removed by sand filtration alone.
This leads to greater chlorine demand and cloudy, dull-looking pool water. The PWTAG recommend flocculation to prevent filter breakthrough of Cryptosporidium (99.9% removal). PAC is being added to many existing installations for the benefits previously given and on new dosing installations there are nearly always fitted and have become the norm.
We can install PAC dosing systems on new or existing installations and can be used on all types of pools from leisure, competition and learner pools.
Did you know your plant room could be subject to chlorine gas, a potentially fatal and extremely harmful gas? Are you and your staff protected from a chlorine gas incident? This is where the GMS plus gas detection system comes in. This flexible multi-function device warns the operating personnel if a defined concentration of gas is reached in the air, alerting them to evacuate to safety.
The GMS plus is a flexible two channel measuring system designed for gas monitoring in up to two rooms. It can either use a single Chloratect sensor or a pair of Chloratect sensors to measure chlorine gas. The gas concentrations are displayed on the display panel. The peak and average values over the past 8 hours can also be displayed. The desired alarm levels can be set using the menu via a control pad. Two values per channel can be specified. An alarm contact is activated for each limit value and the system will also set off an audible and a visual alarm.
Sterling Hydrotech Ltd, can supply, deliver, install and commission a GMS plus unit for you.