Accepta 2879 is a high performance, multi-component water treatment formulation designed for use in low to medium pressure steam boilers and reverse osmosis systems.
Accepta 2879 contains catalysed bisulphite, for rapid and complete oxygen scavenging, phosphates for the control of precipitation and powerful antiscalants/dispersants to mobilise hardness or iron oxide sludges and prevent scale.
Accepta 2879 gives total protection from scale and corrosion in low to medium pressure steam boilers using de-alkalised or reverse osmosis make-up water with inadequate natural alkalinity and without deaeration, operating at up to 40 barg.
The constituents of Accepta 2879 include bisulfite, phosphate, organo-phosphonate and organic polymer.
- Rapid acting multifunctional formulation for boiler systems.
- Excellent scale and corrosion protection for low to medium pressure steam boilers.
- Combined oxygen scavenger, precipitation control, antiscalant and dispersant.
|Specific Gravity @ 20oC:||1.26|
|Freezing point:||Not Available|
|Solubility in water:||Complete|
*Full details of the product properties are available in the Safety Data Sheet. See below.
Application & Dosage Information
Alkalinity contribution: 10 ppm (as CaCO3) per 100 ppm of product. Suitable where make-up M Alk <10% of TDS.
The dose of Accepta 2879 is the sum of that required to react with the oxygen in the feedwater plus the required reserve.
Accepta 2879 should be dosed to the feed line as far as soon as practicable after leaving the hotwell.
Accepta 2879 may be dosed direct from the drum, or diluted with good quality softened, condensate or feed water. If dosing tanks cannot be filled daily, stored solutions should be protected from oxygenation by atmospheric contact by means of a floating blanket or membrane.
The dosage of Accepta 2879 will vary depending on the average feedwater calcium acidified hardness (CaFW), the feedwater oxygen content and the boiler pressure.
Without a deaerator, the oxygen content of the feedwater in equilibrium with the atmosphere is described below.
|Temperature (oC)||ppm O2|
The phosphate residual level that should be maintained in the boiler is a function of the boiler pressure and boiler design.
For Germany and the Benelux it is suggested to refer to the VdTÜV guidelines for boiler feedwater and boiler water.
Table 1 specifies the suggested boiler water phosphate concentration for boilers operated on feedwater that contains solids:
|Boiler Pressure (bar)||>1 <= 22||> 22 <= 44|
|PO4 (ppm)||10 - 20||5 - 15|
For the UK it is suggested to refer to the British Standard BS2486:1997 for the proper control guidelines for boiler feedwater and boiler water.
Table 2 specifies the suggested boiler water phosphate concentration for shell boilers up to 30 bar:
|Heat Flux (kW/m2)||<= 300||> 300|
|PO4 (ppm as PO4)||30-60||10-30|
For countries outside of Germany, the UK and the Benelux it is suggested to follow the applicable local industry standard.
Product dosage factors for this product are:
- Calcium factor: 162.9 ppm per ppm Ca (as CaCO3)
- Oxygen factor: 102.8 ppm per ppm O2
- Sulphite residual factor: 10.27 ppm per ppm SO3
- Phosphate residual factor: 259.9 ppm per ppm PO4
- Boiler pressure (barg)
- Average feedwater calcium acidified hardness Ca HFW (ppm)
- Feedwater oxygen level (ppm)
- Boiler Concentration ratio (NC)
- Feedwater flow (kT.day-1)
Determine product dosage rate for hardness (Remember to take into account the dilution of the make-up water by any steam condensate being returned to the boiler).
Hardness dosage (ppm) = (Ca HFW) x (162.9)
Determine product dosage to maintain the proper phosphate residual in the boiler water: PO4 residual dosage = (ppm PO4 residual desired) x (259.9) / NC
Determine the total phosphate dosage necessary:
Total PO4 dosage (ppm) = Step 2 (ppm) + Step 3 (ppm)
Determine product dosage rate for oxygen:
Oxygen dosage (ppm) = O2 level (ppm) x 102.8
Determine product dosage for residual sulphite:
Residual SO3 dosage = [Desired SO3 residual (ppm) x (10.27)] / NC
Determine product total dosage rate for oxygen:
Total O2 dosage = Step 5 (ppm) + Step 6 (ppm)
The final dosage should be selected between Step 4 and Step 7 in the following way:
- If Step 4 (ppm) < Step 7 (ppm), chose Step 7 (ppm), so the product demand for oxygen corrosion control is satisfied *;
- If Step 4 (ppm) > Step 7 (ppm), chose Step 4 (ppm)
Accepta 2879 must be fed continuously into the feed-water line upstream of the boiler feedwater pump.
Any interruption in feed will immediately result in scale formation corrosion feedwater line and in the boiler.
To ensure proper distribution, entrance to the feedwater line should be via a stainless steel injection quill extending beyond the internal surface of the feedwater line.
It is recommended that Accepta 2879 be fed neat, however where dilution is required, feedwater, cooled condensate (<32°C) or demineralised make-up should be used.
If feedwater is used for attemperation, Accepta 2879 must be fed down-stream of the attemperation water takeoff. Failure to observe this guideline will result in steam contamination and deposition in turbines, process equipment and the condensate system.
Accepta 2879 must not be combined with alkaline products such as amines, caustic or phosphates.
Do not add other chemicals to neat or diluted Accepta 2879 without first bench testing dilutions for stability.
It is always advisable to carry out a 'Control Of Substances Hazardous to Health' (COSHH) assessment before use.
Safety, Storage & Handling
For full details concerning safety precautions, storage and handling procedures for Accepta 2879 please refer to the latest Safety Data Sheet. To download the latest safety data for this product use the following link: