Nalco PermaTreat PC-191T RO Antiscalant Supplier in Oman
Nalco PermaTreat PC-191T is the antiscalant most reverse osmosis plants in Oman run on when the feed water is high in calcium, sulphate and silica. UV Water Systems supplies Nalco PermaTreat PC-191T in 25 kg cans across Muscat, Sohar, Salalah, Duqm and Nizwa, with technical dosing support for each plant.
This guide covers what the product does, the dose rates we use in Omani conditions, and how to store and handle it on site.
What Nalco PermaTreat PC-191T Does in an RO Plant
PC-191T is a liquid polymeric antiscalant fed continuously into the RO feed line ahead of the high pressure pump. As permeate is removed, the salts left behind in the concentrate stream become more concentrated. Once a salt passes its solubility limit it crystallises on the membrane surface, output drops, and differential pressure climbs.
The antiscalant works on three mechanisms:
- Threshold inhibition — holds scale-forming salts in solution above their normal solubility limit
- Crystal distortion — deforms any crystal that does start to form so it cannot grow into a hard deposit
- Dispersion — keeps particles suspended in the concentrate stream so they leave with the reject
It controls calcium carbonate, calcium sulphate, barium and strontium sulphate, calcium fluoride and silica. It is certified for potable water production and is compatible with polyamide thin-film composite membranes, including DuPont FilmTec elements, which is what most plants in Oman use.
Typical Dose Rates for Omani Feed Water
Dose depends on feed analysis and recovery, not on plant size alone. These are the ranges we see across our installed base:
| Feed water source | Typical TDS | PC-191T dose |
|---|---|---|
| Municipal / desalinated supply | 150 – 500 mg/l | 2 – 3 ppm |
| Brackish well, low hardness | 1,500 – 3,000 mg/l | 3 – 4 ppm |
| Brackish well, high sulphate or silica | 3,000 – 8,000 mg/l | 4 – 6 ppm |
| High recovery brackish (above 75%) | Varies | 5 – 8 ppm |
Never set a dose from a table alone. Send a full feed water analysis — calcium, magnesium, sodium, bicarbonate, sulphate, chloride, silica, barium, strontium, pH and temperature — and we run the projection software to return the exact dose and the maximum safe recovery for that water. Under-dosing scales the membranes. Over-dosing wastes chemical and can foul the membrane with the antiscalant itself.
Dosing Equipment and Installation
PC-191T is dosed neat or diluted, depending on plant size. For small plants under 5 m³/h, dilution to 10% in a day tank gives better pump control at low flow. Larger plants dose neat from the 25 kg can through a suction lance.
Points that matter on site:
- Inject downstream of the cartridge filter and upstream of the high pressure pump
- Use a dosing pump with a pulsation damper and back pressure valve for steady delivery — we supply EMEC dosing pumps from Italy for this duty
- Interlock the dosing pump with the feed pump so chemical never runs into a stopped plant
- Fit a level switch on the chemical tank with a low-level alarm
- Do not mix PC-191T with cationic chemicals or with sodium hypochlorite in a common line
Storage and Handling in Oman’s Climate
Summer ambient temperatures in the interior regularly pass 45°C. Store PC-191T in a shaded, ventilated area below 40°C and keep the can sealed. Shelf life is two years in the original container. The product does not freeze at any temperature reached in Oman, so winter storage needs no special measures.
The chemical is mildly alkaline. Operators should wear gloves and eye protection when filling the day tank. Wash any splash with water. Keep the safety data sheet at the dosing station — we supply it with every delivery.
Buying Nalco PermaTreat PC-191T in Oman
We hold Nalco PermaTreat PC-191T in 25 kg cans in Muscat, with delivery across the Sultanate. Alternatives we stock in the same category include Veolia Hydrex 4109 and Culligan Scale Guard 50M17, both proven on Omani brackish water.
For plants already scaled, the antiscalant will not reverse the damage. That needs a cleaning cycle with Hydrex 4731 acid membrane cleaner first, then a correctly dosed antiscalant to keep the membranes clean afterwards.
Frequently Asked Questions
Can I switch to Nalco PermaTreat PC-191T from another antiscalant?
Yes. No flushing or membrane change is needed. Adjust the dosing pump setting to the new dose rate and monitor normalised permeate flow and differential pressure for the first two weeks.
How much PC-191T will a plant consume per month?
A 5 m³/h plant running 16 hours a day at 3 ppm uses roughly 7 kg a month. A 1,000 LPH plant at the same dose uses under 2 kg. We calculate consumption with the quotation so you can plan stock.
Is PC-191T safe for drinking water plants?
Yes, at the recommended dose. It is certified for potable water treatment and is used on hospital, school and hotel drinking water plants across Muscat.
What happens if the dosing pump fails?
Scaling begins within days on high hardness feed. Differential pressure rises and permeate flow falls. Fit a flow switch or low-level alarm on the chemical tank so the fault is caught the same day.
Technical Support
Send your feed water analysis and plant details and we will return the dose rate, monthly consumption and price. UV Water Systems has supplied and serviced RO plants in Oman for over fourteen years, including hospitals, oil and gas sites, schools and hotels.
Call +968 9763 7786 or email sales@waterfilteroman.com.
0 Comments