Desal Supplies

Unit 9, Canal Street Works

Rochdale, Lancs, OL11 1AB

Tel: +44 (0)1706 869777 / Email:


Stock Range Increased

Desal Supplies have made the decision to increase the range of Pass grooved couplings which are held in stock. To compliment the existing low pressure nylon and high pressure duplex stainless steel ranges we now have a medium pressure stainless steel range available from stock.

The medium pressure range of couplings are rated at 42 barg and are available in sizes from ¾" upto 3" NB. As they are manufactured with a stainless steel body, this allows the construction of pressurised pipework systems and RO plants with an affordable corrosion resistant coupling.

For prices and availability please call +44 (0)1706 655522 or email

Click here for more information

Breakdowns and lost production are expensive, especially in the offshore industry where the failure of a single component can mean loss of vital services; therefore the recent failure of fresh water production on an offshore installation was critical due to the loss of production and possible need for evacuation of the rig. The problem was traced to the failure of the reverse osmosis plant high pressure pump which was a traditional triplex piston pump, the necessary spare parts were not available and due to the age of the pump it was becoming increasing unreliable and expensive to maintain.

An initial appraisal revealed that the cost of refurbishing the existing pump was an expensive and lengthy exercise, typically 12-16 weeks. The option to fit a new Danfoss APP pump was then investigated and it was found that the pump complete with, motor, drive coupling and accessories could be delivered in a much shorter time frame and could also offer cost savings on the initial purchase.

Technically the Danfoss pump has many advantages over the triplex pumps, such as a small footprint (it is smaller than the motor), fewer moving parts for improved reliability and reduced service costs, high overall efficiency, a service interval of 8000 hours between major inspections. The pump is a multi piston unit which results in low pressure pulsations and so does not require pulsation dampeners, it is also lubricated by the fluid being pumped and does not require oil changes at regular intervals.

The initial evaluation was submitted to the client in a technical report which the client was able to review and to place orders against. Danfoss were able to manufacture and test the pump on an accelerated production schedule and the client took delivery of the new pump within 3 weeks.


dow_elementDesal have won an order to supply Nanofiltration (NF) membranes, GF Instrumentation, Pass high and low pressure grooved couplings, for a series of 5 drinking water treatment plants due for installation in the Middle East.

NF90 membrane elements were selected because they provide high permeate productivity whilst removing a high percentage of salts, nitrate, iron and organic compounds such as pesticides and herbicides. The low net driving pressure allows operation at low pressures and gives significant energy savings.

Each plant is designed to treat high sulphate borehole water and produce high quality potable water at pressures not exceeding 16 bar.

As part of the equipment support package Desal will also be supplying Genesys operating and cleaning chemicals for the initial operating period.

For more information please click here.

genesys-subcatsAfter the success of Genesol 703 powdered alkaline cleaner which is extremely effective against foulants which are difficult to remove such as clay and biofilm, Genesys International have recently announced the introduction of two new cleaning chemicals, Genesol 701 and Genesol 704.

Genesol 701 and 704 use the same cleaning mechanism as Genesol 703 whereby the layers of foulants on the membrane surface are disrupted by osmosis and the high ionic strength of the chemical.

The concept of disruption has been further developed by formulating cleaning chemicals with components which promote the formation of micro-bubbles. The combination of osmosis and micro-bubbles at the membrane surface enables the layers of foulants to be loosened, which ensures the cleaning chemical is more effective in breaking down and removing these foulants.

Genesol 701 has been developed specifically to clean cellulose acetate membranes. It is an acidic powder cleaner with high ionic strength. The effervescent ingredient has proven to be very effective at removing clay and colloidal deposits as well as iron and mineral scales.

Genesol 704 is an alkaline cleaner with micro bubbles and cleaning agents for particularly stubborn deposits.

gf-9900GF Signet have recently increased their range of analytical and measurement instruments by introducing the new 9900 SmartPro Transmitter. The multi parameter transmitter provides a single channel interface and is suitable for measuring Flow, pH, ORP, Conductivity/Resistivity, Salinity, Pressure, Temperature, Level and any others which output a 4-20mA signal.

The transmitter has an auto-sensing highly illuminated display and large characters which enables better visibility and reduces the risk of misreading the values displayed.

For more information please use the following link:

When designing an RO or NF water treatment system, accuracy is critical to ensure you get the most from your system.

dow_diamond-transparentThe latest ROSA 8.0 (Reverse Osmosis System Analysis) design software from Dow enables the most precise recommendations to optimise system performance and offers the option of a 5 year warranty for systems with a Dow UF pre-treatment facility prior to the RO system.

ROSA 8.0 includes the addition of 3 alternative feedwater types:

  1. Surface water with Dow UF, SDI
  2. Waste water with Dow UF, SDI
  3. Seawater with Dow UF, SDI

System performance is usually characterised by two operation parameters which are product flow and salt rejection. A given feed water analysis should be available so that feed pressure, temperature and recovery can be referenced. Depending upon the system, the goal is to minimise feed pressure and membrane costs whilst maximising permeate quality and recovery.

The steps to successfully design a system are as follows:

  1. Consider feed source, feed quality, feed/product flow, and required product quality.
  2. Select the flow configuration and number of passes.
  3. Select membrane element type.
  4. Select average membrane flux.
  5. Calculate the number of elements needed.
  6. Calculate the number of pressure vessels needed.
  7. Select the number of stages.
  8. Select the staging ratio (array)
  9. Balance the product flow rate.

The ROSA design software can be used to carry out these designs, it is continually evolving to meet the most demanding of system designs and the new version is available now, to download the software please use the following link:

Alternatively, if you require further information or assistance with membrane designs, please contact us with your requirements at .