Multi Grade Filter Manufacturer – Efficient Water Filtration System

Multi-Grade Filter (MGF) — High-Efficiency Industrial Water Filtration System

Protecting your RO membranes, heat exchangers, and downstream equipment starts here.

Trity Enviro designs and manufactures Multi-Grade Filters built for India's toughest industrial water conditions — high turbidity, seasonal silt spikes, hard groundwater, and continuous 24-hour operations. Every system is custom-engineered to your site's water report and flow requirements.

Talk to our engineers today: +91-9821030072

What Is a Multi-Grade Filter?

A Multi-Grade Filter (MGF) is an advanced pressure vessel filtration system that uses multiple layers of graded media — arranged by particle size and specific gravity — to achieve deep-bed filtration across the entire vessel depth.

Unlike a conventional pressure sand filter that traps particles only at the top surface, an MGF captures contaminants through every layer simultaneously. This means higher dirt-holding capacity, longer run cycles, lower backwash frequency, and consistently cleaner effluent output.

The result: Feed water with turbidity below 1 NTU and SDI below 3 — the exact quality your RO membranes and downstream systems need to perform at full rated life.

How an MGF Works: Four-Layer Depth Filtration

Water enters the vessel from the top and passes through four precisely arranged media layers before exiting as filtered effluent from the bottom underdrain system.

After each backwash cycle, the media layers automatically re-stratify in the correct order due to differences in specific gravity. No manual re-arrangement is required.

Key Features and Benefits

• Deep-Bed Filtration The entire media bed depth works simultaneously, not just the surface. This gives the MGF substantially higher dirt-holding capacity compared to single-media filters.
• Consistent RO-Ready Effluent Quality Our MGF systems consistently deliver effluent turbidity below 1 NTU and SDI below 3 — protecting RO membranes from particulate fouling and extending membrane life by two to three times.
• High Filtration Velocity MGF vessels operate at 15 to 25 m/hr filtration velocity versus 8 to 10 m/hr for a pressure sand filter. This means smaller vessel footprint for the same flow duty and lower civil and installation costs.
• 30% Less Backwash Water Our MGF systems use approximately 30 percent less backwash water than equivalent pressure sand filters — a meaningful saving for water-stressed facilities and plants on metered raw water supply.
• Handles Monsoon Turbidity Spikes Indian raw water sources can spike from 10 NTU baseline to 200 to 500 NTU during monsoon season within hours. Our MGF vessels are sized with 20 to 30 percent additional dirt-holding reserve specifically for this condition.
• Lead-Free, Corrosion-Resistant Construction Vessel material options include FRP, MS-RL, SS 304, and SS 316 to match your water chemistry and operating environment.
• Manual or Fully Automatic Operation Choose between manual multiport valve operation or fully automatic PLC-controlled backwash with DP-triggered initiation — depending on your plant's staffing and operational requirements.

SDI and Turbidity: The Numbers That Protect Your RO Plant

If you operate a Commercial RO Plant, these two parameters directly determine your membrane lifespan and cleaning costs.

A correctly specified and maintained MGF from Trity Enviro consistently meets all three targets under normal operating conditions.

Technical Specifications

MGF Sizing Reference Guide

Sizing your MGF correctly from the start prevents underperformance and avoids costly retrofits. Use this reference as a starting point — our engineers will confirm the final sizing based on your water report.

Quick sizing formula:

Filter vessel cross-section area (m²) = Peak flow rate (m³/hr) ÷ Design filtration velocity (m/hr)

For a 60 m³/hr plant at 20 m/hr design velocity: 60 ÷ 20 = 3 m² cross-section → approximately 2-metre diameter vessel.

Contact our team for a precise sizing calculation at no obligation.

Applications

Our MGF systems are installed across a wide range of industries and plant types:

RO Pretreatment The MGF is the most critical component in any RO pretreatment train. It protects membrane elements from particulate fouling and ensures SDI stays consistently below 3. Our clients report up to 40 percent reduction in membrane cleaning frequency after upgrading to a correctly specified MGF.

ETP and STP Tertiary Polishing In Effluent Treatment Plants and Sewage Treatment Plants, the MGF is used as a polishing stage after secondary treatment. It brings TSS below 5 ppm and turbidity below 1 NTU, meeting CPCB reuse and discharge standards.

Cooling Tower Side-Stream Filtration Continuously filtering 5 to 10 percent of the cooling water circuit through an MGF removes suspended solids and biological matter before they accumulate in heat exchanger tubes. This reduces fouling, cuts chemical treatment costs, and extends time between heat exchanger shutdowns.

Pharmaceutical and Food Processing These industries require particle-free feed water before downstream softeners, DM plants, and membrane systems. An MGF protects the Activated Carbon Filters and other downstream units from premature particulate loading.

Wastewater Treatment and Recycling In ZLD and water recycling systems, the MGF ensures that treated secondary effluent meets the turbidity and SDI requirements for high-recovery RO and membrane bioreactor (MBR) feed.

Residential Townships and Commercial Buildings Protects plumbing, appliances, and point-of-use RO purifiers from sediment damage in areas with inconsistent municipal supply or high-silt borewell water.

MGF vs Pressure Sand Filter: At a Glance

Warning Signs Your Current Filter Is Failing

If you observe any of these in your plant, your filtration system needs immediate attention:

Maintenance Schedule Reference

Why Choose Trity Enviro

Custom-Engineered, Not Off-the-Shelf Every MGF system we supply is designed around your actual water report, peak flow rate, downstream equipment, and site conditions. We do not hand you a standard vessel and a price quote.

India-Specific Water Treatment Expertise Based in Ghaziabad, we understand the specific challenges of North Indian groundwater, Ganga basin surface water, and monsoon-season turbidity variability that generic designs do not account for.

Proven Results Our clients report up to 40 percent reduction in RO membrane cleaning costs and consistent CPCB compliance for treated effluent parameters after switching to our MGF systems.

Complete Support We provide installation, commissioning, annual maintenance contracts (AMC), media replacement services, and retrofit automation for existing manual systems — all backed by rapid on-site response.

Free Water Analysis Send us your water quality report and we will provide a technical sizing proposal and system recommendation at no charge before you commit to any purchase.

Related Products

Explore our complete range of industrial water treatment systems:

• Commercial RO Plant — High-recovery industrial and commercial reverse osmosis systems
• Effluent Treatment Plant — End-to-end ETP design, supply, and installation
• Activated Carbon Filters — Chlorine, colour, and organic removal downstream of MGF
• Wastewater Treatment Plant — Complete wastewater recycling and ZLD systems

Get a Custom MGF Quote

Stop letting suspended solids and high turbidity silently damage your RO membranes and downstream equipment. A correctly specified MGF from Trity Enviro pays for itself through reduced membrane replacement costs, lower maintenance downtime, and consistent regulatory compliance.